Accordingly, we adopted a double-blind within-subject protocol in which we delivered a single-session of anodal versus sham transcranial Direct Current Stimulation (tDCS) over the left dlPFC during the completion of a task assessing attention control. We also assessed its subsequent impact on attentional bias. Neither attention control nor attentional bias did significantly improve following anodal tDCS. Although our results do not support our main hypothesis, we believe the present null results to be particularly useful for future meta-research in the field. We also formulated a series of methodological recommendations for future research aiming at testing the tDCS-induced modification of attentional bias.Neurocognitive models of attentional bias for threat posit that attentional bias may result from a decreased activation of the left prefrontal cortex, and especially of its dorsolateral part (dlPFC), resulting in an impaired attention control. Consequently, a transient increase of neural activity within the left dlPFC via non-invasive brain stimulation reduces attentional bias among both anxious and nonanxious participants. Yet, it is still unclear whether the impact of dlPFC activation on attentional bias is mediated by improvement in attention control. In this experiment, we sought to test this hypothesis in an unselected sample ( Prominent cognitive theorists of anxiety disorders have argued that attentional bias for threat—that is, a differential attentional allocation for threat-related stimuli relative to neutral ones—figures prominently in the maintenance, and perhaps the etiology, of anxiety disorders . AccordiThe aforementioned studies suggested that attentional bias for threat can be modified and, in turn, reduce anxiety symptoms. Yet, despite these promising initial results, recent meta-analyses indicated that modifying attentional bias via ABM yielded only a very limited impact—albeit significant—on reducing attentional bias and anxiety symptoms e.g., . HoweverOne common theoretical explanation for the maintenance of attentional bias focuses on general attention control — i.e. the ability to voluntarily regulate the allocation of attentional resources . This hyAltogether, these findings dovetail with longstanding neurocognitive models of attentional bias e.g.,  suggestiduring the completion of a task—did mitigate attentional bias for threat among patients with a DSM-5 diagnosis of social anxiety disorder  applied over the left dlPFC subsequently decreased attentional bias in a sample of nonanxious healthy participants . Likewisdisorder . Moreovedisorder .However, despite increasing research linking attentional bias for threat, attentional control, and PFC activations, there are several limitations to the previous studies. First, prominent models of attentional systems postulate that attention control is a multifaceted construct e.g., , includiversus sham tDCS over the left dlPFC during the completion of a task assessing attention control and, subsequently to the stimulation, on a second task indexing attentional bias for threat. Following the aforementioned HF-rTMS . All participants were right handed. They were recruited via flyers posted in the Université catholique de Louvain community. Exclusion criteria included metal or electronic implants, epilepsy, pregnancy, cardiovascular disease, lifetime history of psychiatric/alcohol/drug dependence, current pharmacological or psychological treatments, corrective eyewear for altered vision, and insufficient knowledge of French language. These criteria were verbally assessed through a medical interview. Participants’ characteristics appear in Table The research was approved by the Ethical Committee of the Medical School of the Université catholique de Louvain (Belgium) and carried out according to the Declaration of Helsinki. Participants provided informed consent, were debriefed upon completion, and were compensated 30€ for their participation.Descriptive measures. To best characterize our sample, participants completed the Beck Depression Inventory . The efficiency of three independent attentional networks  was assessed using the ANT . There were 48 possible trials, based on the combination of four cues , three flankers , two directions of the target arrow  and two localizations (upper or lower part of the screen). Trials were presented in a random order and each possible trial was presented twice within a block. The task was programmed and presented via E-Prime 2.0 Professional® .Probe discrimination task. To assess attentional bias, we used a probe discrimination task modeled on the dot-probe detection task  or a colon (i.e. “:”) by pressing a corresponding button using the right hand as quickly and accurately as possible. They were also instructed to look at the fixation cross at the start of each trial. The probe remained on screen until a response was given. The inter-trial interval was 1500 ms. There were an equal number of trials for each type of stimuli location (top or down), probe location (top or down), and probe type (“.” or “:”). We used an equal number of trials in each condition as a function of these parameters . Each of the 320 trials appeared in a different random order for each participant and each type of stimulation . Stimuli consisted of 40 different face pairs , each pair displaying neutral-disgust facial expressions, randomly selected from a validated version  of the K2). We used a sham-controlled within-subject design in which all participants serve as their own control, a design that substantially increases statistical power. To stimulate the left dlPFC, the anode electrode was vertically positioned centered over the F3 according to the 10–20 international system for electroencephalogram electrode placement. The reference electrode  was placed vertically at the ipsilateral arm  and applied via a saline-soaked pair of surface sponge rubber electrodes , participants started with the ANT. The ANT lasted approximately 20 minutes. Immediately after the stimulation, participants started with the probe discrimination task. The probe discrimination task lasted approximately 15 minutes. Participants were asked to perform both tasks as quickly and accurately as possible. The order of the two tDCS-stimulation conditions was randomly counterbalanced across participants , and the second stimulation was carried out after an exact 48h-interval. Each session was administrated individually in a dimly lit and quiet room.d = 0.7. Setting the level of α at 0.05, power (1 – β) at 0.80 and expecting a conservative correlation of ρ = 0.50 between repeated measurements, the power analysis  for double cue trials from the mean for no cue trials (No cue – Double cue); the orienting effect by subtracting the mean for spatial cue trials from the mean result for center cue trials ; and the executive conflict effect by subtracting the mean for congruent trials (summed across cue types) from the mean for incongruent trials (Incongruent – Congruent). For both alerting and orienting effects, greater subtraction scores for RT indicate greater efficiency. In contrast, greater subtraction scores for RT on executive conflict indicate increased difficulty with executive control of attention . Second, RTs lower than 200ms or greater than 2000ms were removed from analyses . Then, to assess attentional bias, we calculated a bias score for each participant at each session by subtracting the mean latencies when the probe appeared in the same location as the threatening stimuli from the mean latency when the probe and the threatening stimuli appeared at different locations. Hence, positive bias scores represent attention bias toward social threat, and negative bias scores represent bias away from threat, or equivalently, bias toward neutral faces. This bias score is the most frequently used index to determine attentional bias from a probe discrimination task procedure  and Attention Network  with repeated measurement on the two factors and latencies as dependent variable. To investigate the impact of tDCS on attentional bias, we then computed a paired t-test to compare bias scores following sham and anodal stimulation.To investigate the impact of tDCS on the three ANT networks, we first computed a 2 (Stimulation) × 3 (attention networks) repeated-measures ANOVAs for RT with versus sham) × 3  × 2  ANOVA with repeated measurement on the first two factors and ANT latencies as dependent variable. Likewise, we computed a 2  × 2  ANOVA with repeated measurement on the first factor and probe discrimination’s d scores as dependent variable.Following previous studies in the field e.g., , we also2p) for ANOVA and Cohen’s d using the formula for paired comparison (i.e. mean pairs difference divided by the pooled SD).All statistical analyses were performed using SPSS software package (version 20.0). The significance level was set at an alpha level of .05 . Effect sizes are reported in the form of partial eta-squared  = 0.07, p = .93, η2p < .01, implying that the stimulation did not modulate the attentional networks. Likewise, the main effect of Stimulation, F = .24, p = .63, η2p = .01, was not significant. Yet, consistent with earlier studies, the main effect of Network, F = 130.04, p < .0001, η2p = .87, was significant, implying that the three networks did differ. Results are shown in Table The ficant, F,38 = 0.0t(19)= .34, p = .74, d = .33. A comparison between mean latencies when the probe appeared in the same location as the threatening stimuli and the mean latency when the probe and the threatening stimuli appeared at different locations indicated that there was no significant difference between latencies of the former relative to the latter following the sham condition, t(19) = 0.46, p = .88, d = .10 . Similarly, there was no attentional bias for threat following the anodal stimulation, t(19) = 0.12, p = .90, d = .03.As shown in Table Order × Stimulation × Network interaction for the ANT, F = 2.06, p = .14, η2p = .10. Likewise, the Order × Stimulation interaction was not significant for the probe discrimination task, F = .20, p = .66, η2p = .01. These results confirmed that the present findings did not mirror a stimulation-order effect.The ANOVA revealed a non-significant The main aim of the present study was to examine the mediational role of attention control in the impact of anodal tDCS over the left dlPFC on attentional bias for threat, as compared to sham tDCS. Neither attention control nor attentional bias did improve following anodal tDCS. As such, our findings are at odds with previous observation among healthy volunteers of dlPFC-based beneficial impact of non-invasive brain stimulation procedures on attentional bias for threat e.g., . Likewisr(20) = .15, p = .52, dovetails with this claim. Yet, most of those studies were conducted among individuals with clinical anxiety disorders and trait anxiety score might be less than ideal to depict anxiety and related psychopathology  = .46, p < .05, corroborated this observation in our sample.Fourth, we used the ANT to assess attention control. Yet, most of the attentional bias research has assessed attention control using the Attention Control Scale , a self-online versus offline tDCS-induced mitigation of attentional bias for threat in anxious and nonanxious samples.Fifth, while previous tDCS studies administered the probe discrimination task during the stimulation, ours did after. Although we decided to set up our experiment in accordance to our mediational hypothesis vis-à-vis the potential impact of dlPFC-induced attention control improvement on attentional bias mitigation, to the best of our knowledge, no previous studies did collect post-stimulation data. Accordingly, our failure to replicate the tDCS-induced mitigation of attentional bias may merely mirror the non-persistence of the dlPFC-induced benefits at post-stimulation, that is, during the completion of the probe discrimination task. Consequently, an important next step would thus be to compare the Sixth, although our decision to target the left dlPFC relied on previous rTMS and tDCS studies , vlPFC ha priori power analysis was based upon previous tDCS studies on attentional networks  in the present study. However, such small effect sizes have extremely limited relevance for translational research.Finally, our ks e.g.,  and atteks e.g., . HoweverIn conclusion, these limitations notwithstanding, this study constitutes, to the best of our knowledge, the first attempt to test whether attention control mediates the impact of dlPFC-based anodal tDCS on attentional bias for threat. Although our findings do not dovetail with prior research, we proposed several potential explanations for our failure to replicate. Altogether, we believe the present null findings study to be particularly useful for future empirical investigation and meta-research in the field.


When a voltage of 50 V was applied, the surface temperature reached 54.8 °C. The five-coat sample with hot-pressed at 140 °C could be applied to a heat-resistant para-aramid knit glove with the touch screen of a mobile phone and electric heating performance.An electro-conductive para-aramid knit was manufactured by a dip-coating in a graphene/waterborne polyurethane(WPU) composite for confirming to use as a fabric heating element applicable to a protective clothing requiring durability. The para-aramid knit was dipped in 8 wt% graphene/WPU composite solution up to five-coat cycles. As a result of electro-conductive textile by number of dip-coating cycles, the electrical, and specifically electrical heating performances were increased number of cycles from one to five. The sample with the best electrical and electrical heating performance was the five-coat sample, and to improve those properties it was hot-pressed at 100 °C, 120 °C, 140 °C and 160 °C. After hot pressing, the entire surface of the sample was filled with graphene/WPU composite and indicated smoothly surface, thus the electrical and electrical heating performance was improved than the five-coat sample. The best performance of was indicated hot-pressed at 140 °C, with a surface resistivity and capacitance of 7.5 × 10 To improve the electrical conductivity, conductive materials can be used as electro-conductive textiles, such as carbon-based nanomaterials3 or graphene-based materials11. The types of materials are mainly films11, yarns, textiles13, and fabrics20. They can be used for supercapacitors4, sensors such as strain and piezo sensors8, and electrical heating materials11 in wearable textile electronics. The electrical heating fabric is one of the e-textiles which are used to maintain body temperature in extreme environments such as in work clothing, protective clothing, winter sports clothing, and military uniforms, etc., and those products need to light-weight, flexible and durability for activities21.Electronic textiles, or e-textiles, are a class of fabric structures with integrated electronic elements. The incorporation of electrical conductivity in textiles can add a new dimension to their application potential23. Solution mixing is the most commonly used technique to fabricate polymer composites. Graphene has been extensively used as fillers in composites because of the excellent properties that result. Studies have been conducted on graphene as a filler and polyurethane as a matrix for coatings and adhesives9. Recently, waterborne polyurethane (WPU) has been extensively used instead of polyurethane (PU) due to its low content of volatile organic compounds (VOCs)24. To improve the durability of WPU, the incorporation of small amounts of graphene may enhance the electrical, mechanical, and thermal properties. Also, when the graphene fillers form the percolation threshold in the WPU matrix, the electrical conductive path is created and electrical properties are improved25.Graphene is a new and exciting material that has high electrical conductivity, high thermal conductivity, high flexibility, and good thermal and chemical stability20. This method is capable of producing very thin membranes and is promising for high adhesion, reproducibility, and preparation at a large scale. Chatterjee et al.16 studied the electrical conductivity of cotton woven and knitted fabrics with different concentrations of graphene oxide (GO) and the number of coating cycles. They used up to 15 coating cycles, which increased the concentration of GO and the electrical conductivity. Silk fabric was repeatedly dipped into a reduced graphene oxide (rGO) mixture17. The number of rGO sheets increased with the increasing of coats. Thus, the surface resistivity of silk fabrics with 4, 6, and 9 coats decreased to 62.42, 14.75, and 3.24 K Ω cm−1, respectively. Previous studies reported that fabricated electrical heating elements using dip coating with graphene composite were dip-coated on nonwoven fabric19. Liu et al.9 reported that the heating performance for the composite fabrics prepared in an aqueous dispersion containing 0.080 wt% rGO indicated a steady-state temperature of 59 °C within 30 min at 30 V. Kongahge et al.19 was analyzed the thermal behavior of the rGO nonwoven textiles, and the sample of fabric measuring 200 mm × 200 mm with 6 wt% of rGO was heated to an average temperature of 36 °C with 32.5 V and 0.05 A within 10 min.Dip coating is a simple method for coating graphene onto fabrics or textile fibers26 is the simplest route to produce multilayer samples. The process involves pressing independent layers at high temperature. When the layers are heated under high pressure, they stick together via mechanical bonds. The samples then become highly dense, and composite is impregnated in the samples. Cataldi et al.27 studied a healable cotton-graphene/thermoplastic polyurethane nanocomposite conductor for wearable electronics. Folding induced microcracks were applied as defects that affected the properties, and the conductor could be healed easily by hot-pressing to restore the initial electrical conductivity.Hot pressing19. These fabrics can be used in general garments, but they are difficult to use when garments are required durability like bending or friction. Para-aramid fabrics are used in the elbows, knees, and hips of stretchable and durable garments, as well as gloves that require heat resistance and cut resistance. Previous research using para-aramid and graphene has been reported to improve the mechanical and electrical properties of a graphene-aramid nanofiber nanocomposite28. Wearable electronic textiles manufactured by dip-coating carbon nanotubes on Kevlar to fabricate smart armor were reported that the stab resistance performance and dynamic impact resistance was increased compared with the neat Kevlar, and it can achieve a stable electrical conductivity of ~10−2 Sm−1.Generally, fabrics such as cotton or polyester are mainly used for fabricating electro-conductive textiles due to commercial availability, usefulness, comfort, and low costIn the present study, as-fabricated graphene/WPU composite dip-coated para-aramid knit textile which possessed the electrical heating performance was prepared to apply the functional clothing that required flexible, high durability and heat resistance, such as protective clothing, outdoor or leisure sports clothing, etc. Thus, a graphene/WPU composite were dip-coated on the para-aramid knit up to five-coat and then hot-pressed the five-coat sample which indicated the best performance due to enhance the electrical and electrical performance. We also confirmed its applicability to functional clothing requiring durability by establishing optimal conditions. The specific objectives were as follows. First, the 8 wt% graphene/WPU composite solution was prepared, and dip coated on para-aramid knit from one to five times, and then the characteristics of samples by the number of coating cycles. Second, the electro-conductive textile with the best performance was hot-pressed at 100 °C, 120 °C, 140 °C, and 160 °C, and then the characteristic were analyzed according to the hot-press temperature. Finally, the electro-conductive textile was applied to the para-aramid knit glove to confirm its electrical and electrical heating performances as an e-textile.10 ± 3.5 × 109 Ω/sq and 4.0 × 109 ± 2.3 × 109 Ω/sq, respectively. However, when increasing the dip-coating cycles from 2 to 5 times, the surface resistivity decreased from 1.9 × 106 ± 1.2 × 106 Ω/sq to 3.1 × 104 ± 1.5 × 103 Ω/sq, and the weight increase changed from 38.70% to 125.50%. The electrical properties were thus enhanced with increasing amount of graphene added to the knit. It was shown that the three, four, and five-coat samples could be used as an electrical conductor to light two light-emitting diodes (LEDs). Chatterjee. et al.16 reported that the surface resistivity of cotton woven fabric and knit fabric were 0.26 MΩ/sq and 0.19 MΩ/sq after 15 dipping cycles with a 2.25% GO concentration. This may be due to the higher graphene added on to knitted fabric (3.96%) than that of the woven fabric (3.30%). Cao et al.20 fabricated a multifunctional silk fabric via graphene oxide repeatedly coating. They reported the four-coat silk sample and eight-coat silk sample could be used as an electrical conductor to light the LED lamps, but the brightness of the LED lamps for the eight-coat silk sample is higher than that of four-coat silk sample. And the surface resistivity of four-coat and eight-coat silk samples indicated about 60 kΩ/cm and 5 kΩ/cm, respectively, it was reported indicating the lower surface resistance of eight-coat silk sample. With more graphene added to the fabric, it was possible to make more connections between the graphene and fiber matrix due to the increased number of conductive pathways.The dip-coated knits were indicated an obvious color change as the dip-coating cycles increase compared with the uncoated para-aramid knit Fig. . The par30. To investigate the performance of the conductive textile for a touchscreen, the capacitance value of the knits was measured, as illustrated in Fig. 31.Most fabrics reduce the conductance of the skin by blocking the current passing from the skin to a touchscreen and reducing the pressure sensitivity. Conductive fabrics for touchscreens must be able to conduct electrical currents from the wearer’s skin. The resistance of a conductive material simply refers to how well the material can conduct a charge from skin to a capacitive touchscreenFor confirming the electrical heating properties of electro-conductive textiles dip-coated with graphene/WPU composite, the surface temperature of samples was shown in Fig. 32. However, samples with four and five coats expressed hardly voids in the surface and filled with graphene/WPU composite and expressed more regularity surface than samples with one to three coats. As seen in the Fig. As shown in the Fig. P = I2R . As the mention above, for the same applied voltage, a lower number of dip-coatings results in lower electrical heating properties. It was occurred because the number of graphene particles that have electrical heating properties was small. Also, the electrical heating properties were improved as the number of coats increased because it was attributable to the increase in the number of graphene particles.The electrical heating performance can be explained by Joule heating, where the electrical power is defined as et al.9 reported the composite fabric prepared in an aqueous dispersion containing 0.080 wt% rGO, a steady-state temperature of 59 °C reached in less than 30 min at 30V. Thus, the electro-conductive para-aramid knit has been found to reach steady-state temperature sooner. And it was confirmed that could be maintained the electrical heating performance for long time used.As the results of electrical heating behavior for confirming the application of fabric electrical elements was indicated in Fig. 32. And increased samples density with compression process such as and hot-pressing27 and rolling32 could be increased the conductivity due to the conductive pathway increases. Therefore, this study was conducted the hot-press process applied at various temperatures to enhance the electrical properties.As shown in Fig. SEM images of the hot-pressed samples Fig. , all theet al.33 reported that the intensity of the diffraction signal originating from carbon-based nanofiller increases with respect to the polymer-based crystal diffraction peaks. This results from the alignment of graphite flake fillers inside a polymer matrix. Thus, the graphene inside the WPU matrix could be re-oriented after hot-pressing and established a conjugated graphene network in the graphene/WPU composite. When hot-pressing at 160 °C, there was slightly lower intensity, which could be explained by the morphology in the SEM images. It is due to the samples hot-pressed at 160 °C showed cracks on the surface, which act as defects in the crystal properties and electrical properties.As the results of XRD pattern of the electro-conductive textile by different hot-press temperaturesFig. , the dif5 Ω/sq, 2.5 × 104 Ω/sq, 1.4 × 104 Ω/sq, and 2.1 × 104 Ω/sq, respectively , where ε is the dielectric constant of the dielectric between the electrodes, A is the area of the electrodes, and d is the distance between the electrodes. This was used for determining the capacitance34. An amount of charge can be accumulated in the coated hot-pressed knits. The capacitance of the sample hot-pressed at 140 °C was the largest, and it decreased for the sample hot-pressed at 160 °C. Thus, the sample of hot-pressed at 140 °C was more easily to touch screen than control sample (see Supplementary Video Demonstration). This tendency was also shown in the electric heating properties  was used as the substrate fabric. Figure 10, graphene/WPU composite solution and film was fabricated with various graphene contents as 0, 2, 4, 8, and 16 wt%. The aggregation of graphene particles was indicated from 8 wt% graphene/WPU composite film due to the pristine graphene tends to form irreversible agglomerates through van der waals interaction35. And the electrical property was indicated from 8 wt% graphene/WPU composite films. And the electrical property was improved 16 wt% graphene/WPU composite film but it was brittle and crushed after the annealing treatment. Thus, the 8 wt% graphene/WPU composite was selected due to the better formability with the electrical properties. The knits were prepared by dip-coating with the graphene/WPU composite solution. For the first dip-coating cycle, the knit was dipped in the solution for 60 min to reach an average wet pickup of 100% and then dried for 30 min at 80 °C in a drying oven . Subsequent coatings were applied using the same procedure up to five times. Curing was carried out at 120 °C for 30 min. The thickness of the five-coat sample was 1.11 ± 0.05 mm. Afterwards, the five-coat samples were hot pressed at 3.5 bar  for 3 minutes at temperatures of 100 °C, 120 °C, 140 °C, and 160 °C. The range of hot-press temperatures was set by thermogravimetric analysis, as shown in Fig. Graphene  was prepared by a proprietary chemical exfoliation method. The graphene has 3–10 layers, lengths of 5–10 mm, and thicknesses of 3–6 nm. Waterborne polyurethane  was used, and the solid content was 50%. The solvent used was distilled water. Para-aramid knit  = (W/D) × R’, where R’ is the resistance measured by the multimeter, W is the width of the sample, and D is the distance between the two electrodes.To investigate the morphology of the coated knits, the samples were measured by fabric image analysis microscopy  at 6.5x magnification and FE-SEM  at 300x and 20,000x magnification. X-ray diffraction (XRD) spectra of the knits were analyzed using an X-ray diffractometer  using Ni-filtered CuKα radiation. To measure the electrical properties, the surface resistivity was measured by a multimeter  based on a modified version of the AATCC-76 method. Two parallel conductive probes were placed in contact with both edges of the samples. The sample size was 25 mm × 25 mm. The surface resistivity The capacitance of the coated samples was studied using a HIOKI-IM 3570 high-precision impedance analyzer at a frequency of 1 kHz and a voltage of 1 V at room temperature. Samples with the same thickness were measured using two electrodes at the top and bottom with diameters of 2.5 cm. The electrical heating properties were measured with a DC power supply . The sample size was 25 mm × 25 mm, and copper tapes were attached to both edges of the sample to connect to the power source via alligator clips. The aim of our research was to fabricate a fabric heating element that exhibits 50 °C. This study was presented over 50 °C when 50 V was applied, thus the applied voltage range was set from 10 to 50 V (DC). A thermal imaging camera  was used for measuring the surface temperature when applying the voltages. Used surface temperature was the position of middle of the samples. Five samples were measured and mean value was used. To measure of electrical heating behavior of samples, temperature data logger  and temperature sensor  were used. Samples are applied 50V, and for 1 hour and the temperature values was measured until the temperature reached equilibrium state. Five samples were tested and the average was obtained and then the value was used. And the deviation was from calculated from five samples.Supplementary video_Figure. 1(h)Supplementary video_Figure. 3(b)Supplementary video_Figure. 4(c)Supplementary video_Figure. 4(d)Supplementary video_Figure. S1(d)Supplementary information


The physical, chemical, morphological, and electrical properties of the laser-produced graphene were investigated for different laser energy densities. The results demonstrate that graphene was produced in the form of small islands with quality, density, and properties depending on the applied laser energy density. Furthermore, the produced graphene exhibited a sheet resistance characteristic similar to graphene grown on mono-crystalline SiC wafers, which indicates its potential for electronic device applications.This article reports a novel and efficient method to synthesize graphene using a thermal decomposition process. In this method, silicon carbide (SiC) thin films grown on Si(100) wafers with an AlN buffer layer were used as substrates. CO Nowadays, the synthesis of high-quality graphene has been the focus of several researchers due to the great potential applications of this material in electronic devices, sensors and flexible displays .Among the graphene synthesis methods, the thermal decomposition processes have been successfully used to grow graphene layers on silicon carbide (SiC) ,3,4,5. I4 (1064 nm) laser to promote the heating of the SiC surface [−5 Torr. Using an ultra-high vacuum (UHV), only a disordered graphite phase was observed [2) laser beam was used as the heating source, and the argon gas flow at atmospheric pressure was applied to form layers of EG. An advantage of using a CO2 laser is the cooling effect during pulsing, and the possibility of writing graphene patterns on SiC, which eliminates the lithographic step [Most recently, the use of a laser beam as a heating source for graphene formation from SiC has been reported ,14,15. T surface . They reobserved . Lee et hic step ,17.2 laser beam [2 laser beam heating technique for EG growth. Herein, SiC thin films were grown by high-power impulse magnetron sputtering (HiPIMS) on Si substrates covered with an aluminum nitride (AlN) buffer layer. To the best of our knowledge, the formation of graphene from SiC thin films grown on AlN/Si substrates using a CO2 laser beam has not yet been reported in the literature [In another recent study, Galvão et al. reported on the growth of graphene layers on a low cost polycrystalline SiC substrate obtained from powder metallurgy using a COser beam . Althougterature . The groterature ,21,22. Tterature . Furtherterature .In this work, different levels of laser energy density were applied during SiC thermal decomposition, and the chemical properties and quality of the graphene were evaluated using Raman spectroscopy. Moreover, to further understand the material characteristics, morphological and electrical measurements were performed using atomic force microscopy (AFM) and the four points probe method, respectively.−6 Torr. More details of the magnetron sputtering system can be found elsewhere [−3 Torr for a corresponding flow rate of 20 sccm. A high-purity SiC  target with a 4 inch diameter was used. The sputtering reactor was powered by a HiPIMS power supply (Solvix HIP3 5 kW) with an applied power of 200 W and duty cycle of 5%. The target–substrate distance was approximately 65 mm and the deposition was performed for 10 min. The substrate holder was in a floating potential. Before starting the SiC deposition, a pre-sputtering period (10 min at 200 W) was performed to remove contamination from the target surface. The obtained SiC film on the AlN/Si substrate had an average thickness of 240 nm.SiC thin films were deposited by HiPIMS on pieces of polished p-type Si(100) wafer covered with AlN buffer in a high-vacuum chamber with a background pressure of 6 × 10lsewhere ,26. The The AlN buffer layer was grown on the Si(100) substrate using HiPIMS at Institut des Matériaux Jean Rouxel in Nantes University. More details can be found elsewhere ,28. The 2 laser (Synrad Evolution—125) with a beam diameter of 200 µm, which emits infrared laser radiation at a wavelength band of 10.6 µm. The samples were positioned 5 mm below the laser focal point . For al0 J cm−2 . A lower0 J cm−2 .The structure of the as-deposited SiC films was investigated using Grazing Incidence X-ray Diffraction (GIXRD) with an incidence angle (ω) of 0.3° operated with a PANalytical X’pert Pro x-ray diffractometer  with CuKα radiation.−1 and 1200–2900 cm−1, respectively. The Raman spectral imaging (or Raman mapping) were obtained by focusing on the main characteristic bands (or peaks) of graphene. The type of defect present in the graphene film was inferred according to Eckmann et al. [3-defects, (~7) for vacancy-like defects and, (~3.5) for boundary defects [Raman analyses were performed using a Horiba Raman microprobe system  equipped with an argon ion laser (514.5 nm). Raman spectra of the SiC and graphene samples were obtained at room temperature in the range of 200–1100 cmThe surface morphology was investigated by atomic force microscopy  (AFM Veeco Multimode with a Nanoscope V control station). The tapping mode was used for all samples except for sample C2, where contact mode was applied because it provided images with better resolutions.In the literature, there is only one report of SiC growth on a Si substrate using HiPIMS . Howeverα-SiC (6H-SiC), however, it can be not excluded that β-SiC (3C-SiC) exists.In addition, the orientations of SiC indicated in the GIXRD spectrum agree with some studies in the literature ,32,33. W−1), corresponding to the doubly degenerate E2g phonon mode at the Brillouin zone center; (ii) D-band (1200–1400 cm−1), that arises from TO phonons around the K point and requires a defect for its activation; and (iii) 2D-band (2400–2800 cm−1), which is the second order of the D-band and has been widely used to evaluate the number of layers and structural quality of graphene [Raman spectroscopy is a very useful technique to obtain important information about inherent features of carbon materials, such as graphene ,35,36,37graphene ,37.The bright spots observed in the Raman maps , which a2 laser heating. Thus, according to the behavior observed by Raman mapping, and considering that the SiC film is polycrystalline and contains some amorphous areas, it is possible to presume that graphene was grown on both Si–C face terminations. Growth on these two possible faces can result in graphene regions with a high defect concentration and different layers. In addition, the laser heating may have also influenced the growth and quality of the graphene. As obtained by Galvão et al. [When the C-face is considered, the growth rate is higher and its control is more difficult, which usually results in the formation of an inhomogeneous graphene layer ,38,39. Ho et al. , the limFinally, regarding the quality of graphene, the type of defects present in the sample were determined from the ID/ID’ that was calculated from the Raman spectrum, collected at five random points of each sample. The values of the ID/ID’ found were 3.7 ± 1.0, 4.1 ± 0.5 and 3.7 ± 0.7 for the samples C1, C2 and C3 respectively. According to Reference , these rAs graphene is a material of great interest for electronic device applications, we have also analyzed the sheet resistance for each sample produced by the developed method . In all Before analyzing the surface morphology of the treated samples, it was important to verify the morphology of the SiC surface. 2 laser has a strong influence on the quality of the graphene grown on SiC film, which allows for the control of up to three orders of magnitude of material resistivity.2 laser beam heating without vacuum or controlled atmosphere. Raman mapping, along with AFM measurements, revealed the formation of islands of graphene on the SiC surfaces. The quality and density of the graphene islands was shown to be strongly dependent on the energy density of the laser process. It was observed that an energy density of the order of 137 J cm−2 allowed for obtaining interconnected graphene layers with some defects along the surface, resulting in a sheet resistance characteristic of graphene grown on pure crystal SiC wafer. Conversely, when the energy density was increased to 145 J cm−2, the density of the defects was considerably reduced. Finally, the results of this work demonstrate the feasibility of using the laser beam technique as a heating source for graphene formation on SiC thin films. This gives rise to new possibilities to explore the development of graphene layers on different substrates using the same methodology proposed here, which is a desirable situation for making different microelectronic and microelectromechanical systems (MEMS) devices. Given that the microfabrication processes are already well established for silicon wafers, there are still open issues related to SiC bulk etching.For the first time, we approached a feasible route for graphene growth based on the thermal decomposition of polycrystalline SiC thin films deposited by HiPIMS on AlN/Si substrates. For this purpose, we used CO


The synergistic effect of using κ-carrageenan bionanocomposites with the hybridization of cellulose nanocrystals (CNCs) and organically modified montmorillonite (OMMT) reinforcements was studied. The effects of different reinforcements and filler contents were evaluated through mechanical testing, and morphological and water uptake properties. The tensile strength and Young’s modulus of both bionanocomposites increased with filler loading and optimized at 4%. OMMT incorporation into the κ-carrageenan/CNCs bionanocomposites resulted in further mechanical property improvement with an optimum ratio of 1:1 (CNCs:OMMT) while maintaining high film transparency. X-ray diffraction and morphological analyses revealed that intercalation occurred between the κ-carrageenan bionanocomposite matrix and OMMT. The water uptake of the κ-carrageenan bionanocomposites was significantly reduced by the addition of both CNCs and OMMT. The enhancements in the mechanical properties and performance of the hybrid bionanocomposite indicate compatibility among the reinforcement, biopolymer, and well-dispersed nanoparticles. This renders the hybrid CNC/OMMT/κ-carrageenan nanocomposites extremely promising for food packaging applications. Eucheuma cottonii), naturally contains one negative charge per-disaccharide unit which can form a strong and rigid gel; further, it has great potential as a film-forming material. Carrageenan is unique in that it possesses both hydrophilic and ionic properties the latter influencing the former, which provides interesting possibilities for applications. More specifically, κ-carr is promising because of its excellent properties, including nontoxicity, biocompatibility, and biodegradability, which have enabled their wide use in the food, cosmetics, and pharmaceuticals industries. However, κ-carr films have exhibited relatively poor performance because of brittleness and barrier properties which limit their use in applications.This research focuses on the hybridization of polysaccharide, nanocellulose, and modified nanoclay to overcome the problem of low strength performance which is characteristic of bioplastics, by improving the mechanical properties. Polysaccharide from plants, such as κ-carrageenan (κ-carr) extracted from red seaweed (Hibiscus cannabinus) are particularly interesting since this fiber is readily available, which renders it cost effective. Natural nanofillers’ other benefits include high specific strengths and moduli, good adhesion, relatively high aspect ratio, lighter weight, and biodegradability [Bio-based or natural organic fillers, such as cellulose nanocrystals (CNCs) that have been isolated from cellulose, have attracted considerable interest within the biopolymer community owing to cellulose’s renewable nature. CNCs extracted from kenaf fiber  layered clay, with a negatively charged surface, compensates with an exchangeable cation. The polarity of OMMT is different from that of the biopolymer, with parallel layers linked together by weak electrostatic forces. The long organic chains with positively charged ends inside the OMMT gallery result in an increase in the gallery height. This facilitates polymer-chain intercalation . Clay ha3− groups, was not investigated; thus, the current research is the first comparative study in this area. Addition of hybrid reinforcement CNC and OMMT in κ-carr polymer is expected to improve composite-polymer interfacial interaction and improve the properties the properties of the bionanocomposite.Hybrid bionanocomposites have been used in diverse interesting applications in different fields due to the properties that arise from the synergistic effects that occur in the reinforcement region . GrowingThis paper discusses the development of novel nanohybrid inorganic nanoclay/organic nanofillers based on the κ-carr biopolymer in a one-step/in situ process and the synergistic effects of the nanohybrid on the mechanical and barrier properties.The κ-carr was obtained from TACARA Natural Carrageenan  with a moisture content <12%, pH 9–10. Raw kenaf fibers were supplied by Kenaf Fiber Industry Sdn. Bhd. . OMMT with 25–30 wt% methyl dihydroxyethyl hydrogenated tallow ammonium . Sigma-Aldrich , sulfuric acid (98%), glacial acetic acid (99.5%), sodium hydroxide, sodium chlorite, and glycerol (99.5%) were used as plasticizers for the bio-nanocomposite fabrication and were purchased from SYSTEM-chemAR .Cellulose nanocrystals from kenaf were prepared by sulfuric acid hydrolysis according to a previously described method . The natThe κ-carr bionanocomposite films, with the addition of CNCs and OMMT, were fabricated using evaporation casting. A composite with different phases/polarities with an adequate uniform dispersion of hybrid nanoparticles was produced by relying solely on the specific composition and nanoparticle types (CNCs/OMMT) without the addition/involvement of any stabilizers. Step 1: the bionanocomposite film was prepared with single filler loading. The CNCs and OMMT amounts in the composites varied between 2% and 8% (dry weight basis). The film-forming solution containing κ-carr, glycerol, and fillers were prepared using water as a solvent. The solution was heated at 70–90 °C with continuous stirring to obtain a homogeneous gelatinized suspension. The heat was removed and the suspension was stirred continuously for an additional 30 min. A casting knife was used to control the film thickness before it was allowed to dry at room temperature. Step 2: the hybrid bionanocomposite films were then fabricated with the same evaporation casting technique with the hybridization of CNCs and OMMT fillers at the optimum individual nanofiller content based on the tensile test. In order to achieve a homogeneous solution, all film-forming solutions were homogenized for 15 min to prevent particle agglomeration in the matrix phase. The final film thickness was achieved in the 30–50 µm range.The composite films’ mechanical performance was evaluated by measuring the tensile strength and modulus with a universal testing machine  at room temperature according to the ASTMD882 standard; this is the standard for thin plastic sheeting (film) tensile testing. A 5 mm/min cross speed, 40 mm initial grip distance, and 50 N cell load were used during these tests. The film thicknesses were determined at five points using a digital caliper . The average value of seven repetitions for each sample was obtained.The bionanocomposites were characterized by X-ray diffraction to identify nanoclay separation, and nanoparticle and bionanocomposite crystallinity. The diffraction patterns were recorded with radiation (λ = 0.154 nm) generated at 40 kV and 40 MPa, over the 3–50° range.The dimension and morphology of the kenaf fibers were determined by transmission electron microscopy (TEM) . A suspension droplet was deposited on a copper grid and covered with a thin carbon film. The CNCs were stained with 2% uranyl acetate solution in deionized water for 1 min and dried at room temperature to enhance the contrast in TEM. The bionanocomposite surfaces were also examined by TEM. The κ-carr bionanocomposite micrographs were obtained from film-forming suspension microdrops cast directly onto the TEM observation grid. The suspension was stained with a 2% uranyl acetate solution for 3 min prior to casting. The cross-section fracture was also studied using field emission scanning electron microscopy  (FESEM). The composite films were frozen in liquid nitrogen and broken into small pieces. All samples were coated with gold before observation.Wi) of the dry sample was measured. Samples were added to 50 mL of distilled water at room temperature and then filtered through Whatman No. 1 filter paper. The final weights of the sample were then measured. Water uptake (%) = (Wi − Wf) × 100/Wi.Water absorption for each sample was determined by the weight difference every 5 min. Prior to water exposure, the initial weight (The tensile strength of the κ-carr bionanocomposite films with the addition of CNCs (κ-carr/CNCs) and OMMT (κ-carr/OMMT) was determined a. κ-carrThe significant improvement observed for the κ-carr/OMMT bionanocomposite is primarily attributable to κ-carr’s negatively charged poly(disaccharide) units, despite the difference in the matrix and filler polarities. The homogeneously well-dispersed OMMT facilitates interactions that lead to improvements in the bionanocomposite film’s mechanical properties; this is probably due to the OMMT layer’s organic-cationic nature that is located between the platelets and anions at each platelet’s surface. The cations inside the structural gallery play unique roles to stabilize and reinforce by facilitating and strengthening interactions between κ-carr and OMMT. These ionic interactions lead to polymer chain intercalation; intercalation of OMMT and the polymer matrix creates stronger interfacial interactions between the polymer and OMMT surface.d001 = 1.86 nm). Intercalation/exfoliation causes the diffraction peak to shift toward a lower angle [d001 = 1.91 nm). Only a small increase in the clay d001 from 1.86 to 1.91 nm was achieved since κ-carr and OMMT possess different affinities, rendering it easily intercalated into the OMMT interlayer spacing. Previous research has demonstrated that the intercalation of biopolymer cassava starch in silicate layer montmorillonite (MMT) occurred at 17.62 Å (1.76 nm) for a nanocomposite film at 4 wt% of montmorillonite [+-MMT intercalation with cationic functional starch showed basal d001-spacing (1.26–1.44 nm) [However, OMMT exhibits a characteristic crystallinity peak at 2θ = 4.86° (er angle . The 4% illonite . Anotherillonite . The XRD1.44 nm) . The low1.44 nm) . These r1.44 nm) ,24,30,31d001), of 1.8 nm for OMMT itself; due to cationic exchange insertion between the platelets, the polymer chains can diffuse into the interlayer gallery. Polysaccharides exhibit a polyelectrolyte behavior and, similar to carrageenan, are primarily polyanions. The formation of a physical network, stabilized by ionic interaction between OMMT and the κ-carr chains through cationic exchange, occurs because of the basal spacing, d001, leading to a good interfacial interaction. Even with a slight increase in basal spacing, intercalation occurs between κ-carr/OMMT. However, OMMT hybridization with CNCs in the polymer resulted in an OMMT broad peak at a lower 2θ value (3.85°) for the composite film due to the expansion in the interlayer spacing (d001 = 2.29 nm).These interesting examples of layered silicate montmorillonite with natural biopolymers are promising for improving the reinforcing effect in applications for enhanced performance. However, the strategy of using organo-modified montmorillonite was chosen because of the higher interlayer spacing, or d-spacing  decreases by about 68% over the control matrix. One of the most significant effects of OMMT on the polymer matrix properties is its ability to dramatically improve the polymer barrier properties. OMMT sheets are naturally impermeable; they create a maze of tortuous paths that retards water molecule diffusion through the polymer matrix. OMMT addition results in a nanocomposite that is more hydrophobic in nature. Reinforcement by the hybridization of CNCs and OMMT results in a significant decrease in water uptake, by about 74% at 4% filler loading, compared with the matrix without the filler. This is primarily attributed to the higher tortuosity created by the incorporation of the CNCs network and the distribution of intercalated OMMT in the matrix; both fillers will appropriate the free volume within the polymer matrix which inhibits water molecule diffusion through the nanocomposite, Henriette de Azeredo [CNCs and OMMT were added to κ-carrageenan biopolymer to compare the properties of bionanocomposites reinforced with different organic and inorganic nanofillers. Results showed that the nanofiller content affected the properties of the nanocomposites. The reinforcing effect of the hybridization of both fillers was investigated for various ratios at the optimum filler loading. The hybrid bionanocomposite film exhibited synergistic mechanical properties compared with the nanocomposite film reinforced with individual nanofillers. These synergistic effects were primarily due to the higher crystallinities of both CNCs and OMMT, large specific area, and high aspect ratio with different dimensions, which restricted the matrix mobility, and improved the reinforcement, stiffness, and rigidity. The water resistance of the bionanocomposites was drastically affected with different filler types and hybridization. Both CNCs and OMMT decreased the water uptake of the nanocomposite. Reinforcement by the hybridization of CNCs and OMMT resulted in a significantly decreased water uptake due to the increase in diffusion path tortuosity. SEM images of the sample also revealed internal morphology changes. Regardless of its different polarity, OMMT was compatible with the κ-carr biopolymer, and no phase separation was observed, due to the unique properties of both OMMT and κ-carr that enabled stabilizing ionic interactions.


Such judgements can be important in societal planning and decision making and may vary in different cultural contexts. Six hundred participants in each of China, India, and Sweden made answerability judgments of six difficult knowledge questions. For each question, they choose between three options indicating that they thought the question was answerable and a fourth option: “Nobody can answer that question.” After each question, they rated their confidence that their judgment was correct. Choosing “Nobody can answer that question” was significantly more common for the Swedes and was uncommon in the Asian samples. The Asian samples showed higher confidence in their judgments. We suggest that these differences may be explained by results from cross-cultural research, but this study did not investigate specific mechanisms. Hence, more research is needed.Judgments about whether anyone can provide a relevant and correct answer to a question are called  It can be difficult to judge if questions relating to complex issues have been answered. Furthermore, when questions are seen as unanswered but possible to answer, it can be difficult to judge how much work this will take.The correct answers to important questions like “is there a safe way to store nuclear waste?,” “will the polar-ices melt in 500 years?,” and “is radiation from cell-phones dangerous?” have been debated in politics and within science. In such debates, people may even deliberate if anyone can provide a correct answer, that is, if the question is Answerability judgments of questions of the type exemplified are important since they may affect other subsequent important decisions, e.g., policies about nuclear energy. In general, answerability judgments are likely to be influenced by conditions that relate to the person’s prior experiences due to socialization, upbringing and education, etc. In brief, cultural differences in understanding, cognitive approach, and cues heeded from the social context can lead to differences between countries in the judged answerability of questions. If answerability judgments vary cross-culturally, this would be useful to know in international negotiations and collaborations.It is therefore important to investigate such judgments across cultural variations. Apart from the theoretical interest of this issue, it also holds practical interest since realistic assessments of questions’ answerability are important in many social contexts such as safety , medical or crime investigations, effects of social reforms and new laws, and in the context of existential and religious issues. Moreover, in an increasingly global world, people from different cultures have to interact and try to collaborate in order to find solutions for common challenges involving complex issues such as those exemplified above .The present study investigated answerability judgments in three cultural contexts, China, India, and Sweden, of complex fact-oriented questions concerning health and sustainability related issues. It also investigated confidence judgments of these judgments in the same three countries. The three countries were selected in order to get a spread in cultural conditions that may influence answerability judgments. As described below, research has indicated that the three countries tend to differ in their thinking style.actual answerability and the study does not deal with philosophical problems about truth and knowledge. By measuring judgments of answerability we are trying to tap a person’s belief that “a correct, well-argued, answer at a relevant granularity level can be provided to the question”  correlated strongly with another group of participants’ ratings of how probable it was that someone could answer the same questions today . This result indicates some robustness of different forms of answerability scales. today with a categorical answerability scale where the alternatives were “I know,” “someone else knows,” and “no one knows.” These answer alternatives are similar to those used in the present study.Basic research on answerability judgments is scarce and needed. Much research shows that judgments are influenced by the socially prevalent understanding in the cultural context the judger lives in e.g., . Moreovecollectivistic or individualistic  may be an important cause of the prevalence of a specific thinking style in a society , 2010. FMore specifically, the collectivism/individualism distinction has been linked to a difference in thinking style described as holistic and analytic thinking. People in collectivistic societies such as China tend to show a more holistic thinking style compared to societies in the West, and people in the West, including Sweden, tend to show a more analytic style. The holistic thinking style is more contextual and broad and the analytic style is more focused and abstract e.g., . MoreoveOther cross-cultural differences may also influence answerability judgments. Research has found that Chinese people tend to have a longer time perspective compared with Western people. As reported by Research on the accuracy of confidence judgments has found that people in China and other countries in Asia, including India but not Japan, show more overconfidence than Westerners, specifically the United States . This haConfidence judgments were also measured in this study. However, these were made after each answerability judgment. Therefore, the confidence judgments may not have influenced the answerability judgments. In line with the tendency in previous cross-cultural research on confidence judgments, we expected higher confidence ratings of the correctness of their answerability judgments in the Asian samples compared to the Swedish sample.nobody can answer that question” judgments than the Swedes (Hypothesis 1). One reason for this hypothesis is that Asians may to a higher extent believe in collective efficacy, the possibility that people together can accomplish goals  would make fewer “sh goals  and socish goals . FurtherFinally, given that previous research has indicated that Asians tend to be more overconfident , we expe1 answers were acquired from each of China, India, and Sweden (52.7% men 46.5% women). Table 1 shows the background characteristics for the participants from each country. As shown in Table 1, the mean age was highest in China, education level was highest in the Indian sample, and the proportion females was highest in Sweden. Mean age differed significantly between countries . Participants from India had significantly higher education level than participants from China and Sweden , but the Swedish sample and Chinese sample did not differ significantly from each other on education level. Pearson Chi-square tests showed that the percentage women differed significantly between all countries (p < 0.001).Data were collected in a web-survey until 600 completeThe present study followed ethical guidelines in Sweden for survey data. The Chinese participants were recruited via a Swedish marketing research firm and participants in India were recruited via Mturk. Participants in Sweden were recruited from a pool of adults that had already actively volunteered and signed up for participation in psychological research and can thus be considered consciously aware of participation in general.Participants were recruited from participant panels of adults that had actively signed up to participate in online research. Participants received written information online about the study, that they had the right to end their participation at any time, that participation was anonymous, and that the data would be treated confidentially and only for research purposes. They were also provided with relevant contact information in case they had questions. They gave their consent and agreed to participation by clicking on the survey link.“is radiation from cell phones dangerous?,” “will the polar ices melt in 500 years?,” “is there today a safe way to store nuclear waste?,” “does the human body have an unknown system of circulation?,” “are new electric cars more environmentally friendly than ordinary cars?,” and “is too much stress a greater danger to humanity than overweight?” The first four questions have previously been rated low on answerability in Swedish samples . The first three options were interpreted as indicating that the participant thought the question was answerable. After choosing one of the four response options, participants were asked to judge how confident they were that their answer was correct on a scale ranging from “0%, I am guessing” to “100%, I am completely sure” in steps of ten. After confidence judging their answer, participants clicked on “next” in order to see the next knowledge question. The six pages, each with a knowledge question and a confidence judgment, were presented in a randomized order. It was not possible to go back to questions on previous pages.For each of the six knowledge questions, there were four response options The languages used were: Chinese in China, English in India, and Swedish in Sweden. Necessary translations were made with back-translation procedure .Supplementary Material and is, in the interest of brevity, not be reported in this manuscript.Other questions were also asked. More detailed information about these questions can be found in the Data were collected with a web-survey in China, India, and Sweden. After agreeing to participate in the web-survey, participants performed answerability judgments of the six knowledge questions and after each question rated their confidence in that the answerability judgment was correct. The participants also answered questions about age, gender, and education level.Nobody can answer that question” was interpreted as the question was judged not to be answerable. The other answer alternatives were used in order to make the answerability judgment task natural for the participants. However, our main topic of interest was to measure the prevalence of the belief that the question was not possible to answer by anyone . As can be seen in Figure 1, Sweden scored significantly higher on prevalence of “nobody can answer that question” compared to both China and India on all questions (p < 0.05). Chi-square statistics ranged between χ2 = 12.04 for the smallest difference in prevalence of “nobody can answer that question” (the difference between Sweden and China for the question about electric cars) and χ2 = 71.87 for the largest difference in prevalence of “nobody can answer that question” (the difference between Sweden and India for the question about the polar ice). Taken together these results strongly support our expectation in Hypothesis 1 that Swedes would be more prone to choose “nobody can answer that question.”Choosing the alternative “F = 30.78, p < 0.001. Post hoc analysis was made with Bonferroni correction (p < 0.05). The result provided support for Hypothesis 2, that Asians would show more confidence in their answerability judgments than the Swedes.The Swedish sample provided significantly lower confidence judgments of their answerability judgments for each of the questions compared to the Asian countries, except for the question about a nuclear waste. The method of analysis was a multivariate ANOVA with the six confidence judgments as dependent variable and country as independent, nobody can answer that question.” This is to our knowledge the first study investigating cultural differences in answerability judgments. In line with Hypothesis 1, the Swedish sample significantly more often chose “nobody can answer that question” for each of the six answerability judgments. Choice of this alternative was uncommon among the Asian respondents. Below we discuss some factors that may have contributed to these results.The purpose of this study was to explore how answerability judgments of difficult knowledge questions  differed between Chinese, Indian, and Swedish respondents with respect to the number of choices of the alternative ““nobody can answer that question” responses in their answerability judgments. With respect to belief in collective efficacy, collectivistic countries such as China have been found to show higher belief in this kind of efficacy, that is that people can accomplish goals together (We compared two Asian countries (China and India) with a Western country (Sweden). Although this study did not investigate the specific mechanisms associated with the answerability judgments, results from research in cross-cultural psychology may help explain why the Asian samples gave fewer together , and thiTurning next to thinking style, previous research supports that the Asian samples are more likely to have used a holistic thinking style e.g., . Such dinobody can answer that question”) is positively related to both sensitivity and face-saving concerns. In addition, the Asian schooling system is suggested to be more authoritarian than the Western system  indicates that judgments using these two scales may be driven by the same sort of factors, although this issue is not sufficiently researched. In brief, longer time perspective and greater patience may contribute to a higher general belief that questions are answerable but may not necessarily have contributed to the Asian respondents thinking that questions are answered today.In addition, other factors may have contributed to the Asian samples finding the questions to be more answerable. For example, differences in cultural values such as sensitivity to other people’s opinions, and face-saving strategies may help explain why the Asian samples were more convinced that somebody could answer the question. n system . Such diIn general, as noted, the data from this study do not provide direct evidence that the factors suggested as contributing to our results actually caused our findings and further research should investigate the specific mechanisms associated with answerability judgments in the respective countries. Thus, further research should measure these various aspects directly and relate them to the participants’ answerability judgments.Finally, in line with our expectations, we found the Chinese and Indian samples to be significantly more confident, compared to the Swedish sample on all questions, except one. Thus, our participants evidenced similar results for their confidence in their answerability judgments as previous research has found for confidence in the correctness of direct answers to, for example, general knowledge questions . AccordiLike all research this study has a number of limitations. Some of these are, first, that this was a questionnaire study and the results may not be fully representative of answerability judgments made in real life contexts. Therefore, future research should attempt to study such judgments in contexts that are more similar to every-day contexts, for example, by asking for answerability judgments in the context of more elaborated vignettes, or, even better, but more difficult, study them in real life. Second, our study was conducted on the net and the results, like in much cross-cultural research, are likely to be most representative for well-educated people in urban contexts. Third, our results only pertain to the answerability judgments of six questions. Although these questions were constructed with the aim to be about complex, socially relevant issues, it is still possible that our results primarily are representative for the content domains covered in the questions. Finally, we cannot exclude that there are also other differences in the samples unrelated to culture that matter for answerability judgments.In spite of these limitations, our results highlight the importance that people who participate in cross-cultural collaborations within, or between, countries are aware of the possibility that people with different cultural backgrounds may well judge the extent to which important issues are possible to answer differently. Our results suggest that people from east and south Asia may to a higher extent believe that questions are in fact answerable and they may back up their judgments with different levels of confidence. Such differences may also sometimes influence east and south Asians, compared with Westerners, to collectively be more prepared to take on complex issues to the extent that they may judge the difficult questions relating to such issues to be more answerable.All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


During the heat treatment process, decomposition, sulfuration and N, S co-doping occurred. This hybrid structure was not only endowed with an enhanced capability to buffer the volume expansion, but also improved electron conductivity as a result of the conductive network that had been constructed. The dominating pseudocapacitive contribution (57.78% at 1 mV s−1) enhanced the electrochemical performance effectively. When serving as anode material for lithium ion batteries, VS/NSG exhibits excellent lithium storage properties, including high rate capacity  and stable cyclic performance (692 mAh g−1 after 400 cycles at 2 A g−1).Construction of a suitable hybrid structure has been considered an important approach to address the defects of metal sulfide anode materials. V Lithium ion batteries (LIBs) are the dominant energy storage device in the field of mobile devices. A high capacity, high rate, long cyclic life, and safety are the critical elements for their large-scale application . Traditi2O3 2O3 [2 [5mposites ,8,9,10 hoperties . Howeverere@PANI , VS4 nanles@CNTs , VS4 nannanowire  anchoredsphere@C , and V5Sanosheet ,17 anode.1 A g−1 , and the density . The dur3S4 nanosheets anchored on N, S co-doped graphene have been fabricated through a facile and green method. NH4VO3 and (NH2)2CS were used as vanadium and sulfide sources, respectively. V3S4 nanosheets shorten the transmission path of both electron and Li ions. Meanwhile, the formed N, S co-doped graphene aerogel not only endow the as-prepared anode with the enhanced capability to buffer the volume expansion but also construct a conductive network to improve electron conductivity. Moreover, the dominating pseudocapacitive contribution (57.78% at 1 mV s−1) is effective for improving the electrochemical performances. When serving as an anode material for LIBs, V3S4 nanosheet anchored on N, S-doped graphene exhibits a high rate capacity  and stable cyclic performance at high rate (692 mAh g−1 after 400 cycles at 2 A g−1).In this work, V3S4/N, S-rGO (reduced graphene oxides) nanosheets. In a typical synthesis, 2.5 mmol NH4VO3 and 1.4 g (NH2)2CS were dissolved in 20 mL formed GO (graphene oxides) aqueous solution (5 mg mL−1) at 60 °C. Then, the mixed solution was transferred into a 25 mL Teflon-lined stainless-steel autoclave and heated at 180 °C for 20 h in an oven. After hydrothermal treatment, the formed hydrogel was freeze-dried and annealed at 600 °C for 5 h under Ar atmosphere to obtain the final samples (denoted as VS/NSG).Synthesis of V−1.X-ray diffraction  analysis was carried out to determine the crystal structure of the samples. The morphology and the structure of the samples were investigated by SEM  and transmission electron microscopy . X-ray photoelectron spectroscopy  was performed to determine the valence state of the products. The graphitic degree of reduced graphene oxide was investigated by Raman spectrometer with an excitation laser beam wavelength of 633 nm . To investigate the content of the coating carbon, thermal gravimetric analysis was conducted on a thermal analyzer  in air at a heating rate of 5 °C min3S4 nanosheet anchored on N, S-doped graphene was assembled CR2032 half-coin cells to evaluate its electrochemical performance. The assembly processes were similar to our previous works [−2. The charge–discharge processes were operated at the voltage range of 0.005–3 V using Neware CT3008 . Cyclic voltammetry measurements  and electrochemical impedance spectroscopy  were conducted on the Parstat 4000+ workstation (Princeton Applied Research).Vus works ,20. Typi3S4 phase (JCPDS no. 65-3745). The low intensity of diffraction peaks would be ascribed to the crystallinity of the nanosheet and graphene substrate. In c-axis, which is convenient for the storage of lithium ions. The content of graphene substrate was exposed by TG analysis. After the heat treatment process in air atmosphere, VS/NSG would be decomposed and oxidized to V2O5. In this process, the change of weight is about −3%. According to the results of TG analysis  suggests the more graphitic carbon in the graphene substrate.The preparation process is illustrated in analysis , the conc carbon ,22. The 3S4 nanosheets anchor onto the graphene substrate to ensure their electronic conductivity. As shown in the magnified SEM image  of V3S4 nanosheet is about 71.7%, which is much higher than that of other transition metal oxides and sulfides, such as SnO2 [3O4 [2O3 [4 [3S4 nanosheet. The cathodic peaks located at 1.29, 0.64, and 0.22 V in the first sweep can be assigned to the behavior of Li+ insertion into V3S4 interlayer stepwise and formation of solid electrolyte interface (SEI) layer, respectively [xV3S4 and formation of V3S4 [−1. At this high current density, VS/NSG electrode delivers an excellent cycling stability. After 400 monotonous cycles, as high as 692 mAh g−1 discharge capacity can be retained. The level of coulombic efficiency, being close to 100%, suggests the high reversibility of VS/NSG during the monotonous cycles. As shown in −1 with the ICE only about 60.1%. In the following cyclic test, the bare cell exhibits obvious capacity fading. In the following rate tests, VS/NSG electrode delivers a high reversible discharge capacity from 0.05 to 10 and back to 0.05 A g−1, which reach 480 and 330 mAh g−1 at 5 and 10 A g−1, respectively. Particularly, in the subsequent repetition of rate evaluations, the discharge capacity of VS/NSG at low current densities exhibits an obvious increasing tendency. This phenomenon would be attributed to the increased Li+ storage ability at the enhanced area of electrolyte and electrode interface. When the current density is back to 0.05 A g−1, a high discharge capacity of 1150 mAh g−1 can be retained, indicating the superior rate capability of VS/NSG electrode.The lithium storage performances of VS/NSG were evaluated by CR2032 half-coin cells. As shown in  as SnO2 , CoO [31 [2O3 [4 . After tectively ,13,33. A of V3S4 . The ove−1 . These values mean that surface-induced capacitive would be a dominator in VS/NSG electrode charge storage system. The ratio of surface-induced capacitive in the whole charge storage can be further calculated using Equation (2).According to the previous reports, the value of  storage ,35. As sk1v and k2v0.5 means the surface-induced capacitive and diffusion–insertion process, respectively [k1 at different potentials are the slope of the function of i(V)/v0.5~v0.5 in a series of CV analyses. Based on the various k1 at different potential, the profile of surface-induced capacitive under a certain scanning rate could be depicted. As shown in −1. In addition, the surface-induced capacitive profiles and pseudocapacitive contributions from 0.2 to 0.8 mV s−1 are depicted in −1 is 44.90%, 51.09%, 54.13%, and 56.27%, respectively. Dominant pseudocapacitive effect at fast scanning rate endow the VS/NSG electrode with excellent cyclic stability and rate capability. Moreover, Nyquist plots of VS/NSG electrode at the 3rd and 50th cycle are displayed in Rst, an indicator to the degree of side reaction [3S4 nanosheets anchored on N, S co-doped graphene would induce the dominating pseudocapacitive effect and restrain the increasing of Rst.The integral area of ectively ,37. Furtreaction ,39,40), reaction . The abo3S4 nanosheets anchored on N, S co-doped graphene by this universal and green method exhibits excellent rate capability and cyclic stability. At the current density of 5 and 10 A g−1, the as-prepared VS/NSG delivers a high discharge capacity of 480 and 330 mAh g−1, respectively. At the end of 400 cycles under 2 A g−1, 692 mAh g−1 also can be retained. The superior electrochemical performances of VS/NSG benefited by the formed N, S co-doped graphene aerogel, not only endow it with an enhanced capability to buffer the volume expansion, but also a constructed conductive network that improves its electron conductivity. Moreover, the dominant pseudocapacitive contribution at fast scanning rate and the decreasing resistance of charge transfer also guarantee fast and durable Li+ storage performance.In summary, the fabrication of V


In this paper, the influences of the graphite precursor and the oxidation method on the resulting reduced graphene oxide  are shown. Three types of graphite were used to prepare samples for analysis, and each of the precursors was oxidized by two different methods . Each obtained graphite oxide and reduced graphene oxide was analysed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS). Carbon-based materials are very interesting due to their stable physicochemical properties and low cost, as well as other characteristics . These mrGO is obtained by the oxidation of graphite ) followed by reduction and exfoliation ,7. Curre−1) results from the presence of vacancies or dislocations in the graphene layer and at the edge of this layer. This band is also related to the presence of defects in the material [2 hybridized carbon atoms and is located near 1580 cm−1 [−1 [D/IG ratio (intensity of the D peak to the intensity of the G peak) is related to the amount of defects present in the material [2D/IG ratio (intensity of the 2D peak to the intensity of the G peak) is related to the number of graphene layers in the material [Based on the literature ,15,16,17material ,21,22. T580 cm−1 . The lascm−1 [−1 ,24. Basematerial ,26, whilmaterial ; when thmaterial .−1 (marked as D’) and two (according to other papers- three) additional bands above 2440 cm−1 become visible. There are discrepancies in the name of these latter peaks, where the first peak above 2440 cm−1 is marked as D* or G* and the next peaks are marked as D+D’ or D+G and 2D’ or G+D’ [2D/ID+G (I2D/ID+D’) ratio indicates the restoration of the sp2 hybridized structure [The literature indicates that additional peaks may be visible in the Raman spectra of some graphene-based materials after deconvolution. In our previous work , we pres or G+D’ ,22,28. ATwo types of natural graphite, scale graphite (S) and flake graphite (F), and one synthetic graphite; electrode graphite (E), were used for the measurements. The contents of carbon in these analytical samples in the dry and ashless state are 99.2, 99.5 and 99.5, respectively. These graphites are characterized by a high degree of crystallinity and large crystallite dimensions; however, their properties differ between materials. Due to the spatial arrangement of the flake graphite structure, the bonds between neighbouring planes can be easily broken, resulting in significant anisotropy in this graphite. The natural scale graphite has a coarse crystal structure with large crystals. The synthetic graphite is characterized by a high purity and close similarity to natural graphite; however, it is obtained in a synthetic method from a properly prepared mass in an Acheson electric resistance furnace at a temperature of 2500–3000 °C . The difGROS-A, GROF-A, GROE-A, GROS-B, GROF-B and GROE-B according to the type of graphite used and the method of oxidation. The diagram showing used abbreviations  is shown in Graphite oxides were obtained from scale, flake and synthetic graphites by two methods denoted A and B  and subsequently annealed at 900 °C for 5 min. The obtained rGOs are denoted X-ray diffraction measurements were conducted using an X’Pert PRO PW 3040/60 diffractometer . The samples were deposited onto glass and analysed by using Cu Ka1 radiation with a voltage of 45 kV and a current of 30 mA.XPS was performed using a PHI 500 VersaProbe spectrometer from ULVAC  using an Al Kα anode radiation beam (1486.6 eV).Spectroscopic studies were performed using an N-TEGRA Spectra platform . The vibrations of the molecules were excited using 532 nm wavelength. The exposure time was 10 s. Measurements were performed at ten different points of each sample.a), crystalline height (Lc) and interplanar distance (d002).The first step of the material characterization included determination of the crystallite diameter . The area under the G peak is approximately 7–8 times larger than the area under the D peak. For all analysed graphites, the intensity of the G peak is much larger than the intensity of the D peak.In the next step of the measurements, the Raman spectra of the graphite samples were collected . From thgraphite ). Howeve001) are obtained for the GROFs. The smallest crystallite diameter, La, is observed for the graphite oxides obtained from synthetic graphite, regardless of the oxidation method. The crystalline height (Lc) is similar for all the GROs.The first stage of measurements of the graphite oxides included analysis using the XRD method. Based on the obtained data , the larThe GROs were also analysed using the XPS method . All the2 and sp3 bonds of carbon. Moreover, peaks corresponding to carbon bonded to oxygen dominate the spectra of the GROs: three peaks  that correspond to hydroxyl/epoxy , carbonyl/quinone (C=O) and carboxyl (O=C–OH) groups are identified. Based on the obtained data, the hydroxyl and epoxy groups are the most abundant. Smaller amounts of carbonyl and quinone groups are present, and the carboxyl group content is the smallest (more carbonyl and quinone groups and fewer carboxyl groups are present in the GROs oxidized by method B). Furthermore, the lowest degree of graphite oxidation is observed for the GROSs.To determine the distribution of carbon and oxygen bonds, the C 1s XPS spectra of the graphite oxides were deconvoluted into five components. After deconvolution, two peaks appear at energies (284.5 ± 0.1 eV and 285.4 ± 0.2 eV) that correspond to the spD/IG, I2D/IG, and I2D/ID+D’) are shown in All of the experiments whose results were described above (XRD and XPS) were performed to obtain information about the tested graphites and graphite oxides. This knowledge was helpful for interpreting the data obtained from Raman Spectroscopy (RS). The RS method enables much more detailed analysis of the changes related the introduction of oxygen atoms into the graphite structure, thus increasing the understanding of the unstructured phase. 3 hybridized bonds as a result of the oxidation of graphite. Both the D and G bands of the GROs are wider than the D and G bands in the Raman spectra of graphite. Moreover, the G band of GRO is shifted towards lower wavenumbers, which confirms the presence of defects in the graphene layers.The spectra of GRO are characterized by intense D and G bands and a wide 2D band. Such an intense D band indicates the formation of defects in the structures. The increase in the intensity of the D band in relation to that of the G band indicates an increase in the amount of the disordered phase in the GROs. Unlike in the Raman spectra of the graphites, for the GROs, the D band is more intense than the G band, which is related to the formation of spThe presence of oxygen atoms causes both an increase in the interplanar distance and changes in the characteristics of the vibrations in the material’s lattice. For this reason, the Raman spectra of oxidized graphites are characterized by more intense D peaks in comparison to the D peaks of the unoxidized graphites. If the degree of oxidation is larger, the intensity of this peak is also larger ,31.−1. A D’ band is observed in the spectra of graphene materials obtained from the oxidation or direct exfoliation of graphites and subsequent reduction of the GROs, which confirms the formation of structural defects [The FWHM values of the D and G bands are larger for the GROs than for the graphites. The wide G bands in the GROs are accompanied by a D’ band, the intensity of which is proportional to the number of defects. The FWHM of the D’ peak is in the range from 61 to 66 cm defects ,23,31,32 defects .−1 [The 2D band is less intense than the D band. Based on the position, shape and intensity of the 2D band obtained from deconvolution of the Raman spectrum into components (Lorentz curves), the number of graphene layers can be determined ,34,35. I−1 . In cont−1), 2D (2695–2703 cm−1), D+D’ (2897–2910 cm−1) and 2D’ (3090–3118 cm−1), are obtained after deconvolution. The FWHM of the 2D peak is approximately 230 cm−1, which is much larger than that of the 2D peak of graphene (approximately 30 cm−1) [1 and 2D2 [In the spectra of the analysed GROs, four peaks: D*  as a consequence of the greater degree of exfoliation that occurs during high-temperature processing. The values calculated on the basis of the 002 band are in the range (0.3373–0.3393 nm) for method A and in the range (0.3421–0.3440 nm) for method B. The largest values of the interplanar distances (d00X) are observed for the rGOF materials, while the smallest ones are observed for rGOE. The maintenance of a large distance between graphene layers may be related to the presence of significant amounts of oxygen in the rGOs and a large degree of defect formation in the graphene layers. The crystallite sizes of the rGOs differ depending on the type of graphite used and the oxidation method. The smallest values of Lc and La are obtained for rGOs fabricated from synthetic graphite. Moreover, analysis of the obtained parameters reveals that higher values of Lc and La are obtained for the rGO-A series independent of the type of graphite. This result suggests that a lower degree of exfoliation occurs for the GROs obtained by method A. The resulting rGOs (method A) are characterized by a lower susceptibility to high-temperature exfoliation (larger number of layers).All reduced graphene oxides were examined by the same methods as those employed for the graphite oxides, and XRD measurements were performed first. The structural parameters of the rGOs are shown in Based on the data obtained using the XPS method , a large2 hybridized carbon (78% for A method and 80% for B method) occurs for these samples, and their percentage of sp3 hybridized carbon is the smallest among all the rGOs. Meanwhile, the largest amount of sp3 hybridized carbon in the rGOs is obtained for the samples prepared from synthetic graphite. As a reminder, the lowest degree of reduction, expressed as the C/O ratio, also occurs in the rGOEs.As was done for the GROs, the distribution of carbon and oxygen bonds was determined for rGO using the XPS method. Analysis of the XPS C 1s spectra after deconvolution , thereby confirming that both the reduction and oxidation process contribute to the formation of defects in the graphene layers.Reduced graphene oxides are made of graphene layers with residual oxygen groups attached to the planes and edges. The obtained materials exhibit intense G band and D bands, which confirms the presence of defects in the graphene layers. The FWHM values of the D and G peaks of the rGOs are smaller than those of the GROs, which indicates the presence of fewer defects in the structure (associated with a lower oxygen content). In the spectra of the rGOs, the intense G band is accompanied by a D’ band, the intensity of which is proportional to the amount of defects in the structure. The FWHM of this band is ~61–68 cmThe rGO-Bs are characterized by D* and 2D bands with larger FWHM values compared to those of the rGO-As, which indicates that these samples have fewer graphene layers in their aggregates (as a reminder: the average number of layers determined using the XRD method is 22–28 for the rGO-As and 8–11 for the rGO-Bs). Simultaneously, the FWHM values obtained for the rGO-Bs are larger than those obtained for the GRO-Bs. This result indicates that the aggregates of the rGOs contain fewer graphene layers than the aggregates of the GROs .D/IG ratios. The higher ID/IG ratios obtained for the rGO-B samples confirm that despite thermal reduction of these structures, more defects and imperfections are present in these samples than in the rGO-A structures. This difference can be explained by the higher oxygen content in the rGO-Bs, which is related to larger distances between the layers and a greater degree of exfoliation. The ID/IG values determined for the rGOs depend on the type of graphite used and increase in the order: flake (F) < scale (S) < synthetic (E) graphite . This trend can be related to the size of the graphene layers (La) determined using the XRD method, in which the opposite trend is observed . Based on the measurements performed, smaller graphite crystallites lead to larger amounts of defects in the obtained rGO structures. This relationship was also confirmed in the papers [The intensity of the D peak is lower for the rGO-A samples than the rGO-B samples, confirming that these materials contain fewer defects. This feature further results in lower Ie papers ,37, wher2D/IG ratio is related to the number of graphene layers, and larger values of this ratio are observed for the rGOs than for the corresponding GROs. The smallest values are obtained for rGOE-B, which indicates that this material has the fewest layers in its aggregates. Due to the type of graphite used, the I2D/ID+D’ ratio is the smallest for the GRO-Es. Please note that these materials are characterized by the smallest quantity of sp2 hybridized carbon and the largest quantity of sp3 hybridized carbon (determined by XPS measurements), indicating a high degree of destruction of the graphene layers. Furthermore, the I2D/ID+D’ ratios are the smallest in this case. Conversely, the rGO-Fs are characterized by the largest quantity of sp2 hybridized carbon and the smallest quantity of sp3 hybridized carbon, which indicates the presence of fewer defects in these graphene structures.Analysis of the Raman spectra of the rGOs shows that the intensity of the 2D band is much lower than that of the G band. The ID/IG ratio and the smallest I2D/IG and I2D/ID+D’ ratios are obtained for the oxides prepared from synthetic graphite (E), which indicates that this graphite is the most susceptible to oxidation and exfoliation. In the case of the oxides obtained from flake graphite (F), the smallest ID/IG ratio and the largest I2D/IG and I2D/ID+D’ ratios are obtained. Based on the Raman spectra, an increase in the D band is observed for the GROs in comparison to that of the unoxidized graphite. This increase is related to the formation of sp3 hybridized bonds as a result of the oxidation of graphite. The presence of oxygen atoms causes both an increase in the interplanar distance and changes in the characteristics of the vibrations of the material’s lattice.From comparison of the different oxidation methods, method B is determined to be more effective for introducing oxygen into the graphite structure (more carbonyl and quinone groups and fewer carboxyl groups are present). Furthermore, comparison of the type of precursor (graphite) used shows that the synthetic graphite (E) is the least susceptible to oxidation. This conclusion is confirmed by the results of RS. The largest I2, CO and H2O, which leads to a weakening of the van der Waals forces between graphene planes, and as a consequence, individual graphene sheets are obtained. In such a process, complete elimination of oxygen from the graphite structure cannot be achieved, and the obtained product may contain even several percent of oxygen depending on the degree of reduction.Please note that rapid degradation of the oxygen groups occurs during thermal exfoliation and reduction of GRO. This degradation is accompanied by an increase in pressure due to the evolution of COAnalysis of the data obtained from XPS measurements reveals that the degree of reduction (represented as the C/O ratio) changes in the order rGOE < rGOS < rGOF.D/IG values, which indicate the content of defects in the structure, of the rGOs increase in the order rGOF < rGOG < rGOE. This trend is related to the size of the graphene layers (La), which exhibits the opposite trend (rGOE < rGOS < rGOF).The IAs we have proven, both the type of graphite used and the method of oxidation have a fundamental influence on the properties of the resulting rGOs. Further research on the prepared materials will include studies of their electrical properties. The sensitivity of selected parameters to the surrounding environment will also be tested (the rGOs will be applied as sensor layers in gas sensing devices).This work involved various advanced research methods that enable deeper analysis of the changes related to the incorporation of oxygen atoms into graphite oxides and reduced graphene oxides.The research facilitated the development of preliminary criteria for the selection of a graphite precursor for the preparation of reduced graphene oxides with the desired textural and structural parameters. The reduced graphene oxides obtained from flake graphites, which had the largest crystallite diameter among the analysed graphites, were characterized by the highest degree of reduction and the fewest defects. Moreover, in each investigated case, large crystallite dimensions in the graphite precursor corresponded to large crystallite dimensions in the obtained reduced graphene oxide (regardless of the oxidation method).This work also showed that the oxidation method has a large influence on the studied parameters of the obtained materials. The research allowed to indicate which of three graphite precursors is the most susceptible to oxidation and what structural and textural parameters will graphene materials have after exfoliation/reduction process. Graphite oxides obtained by method B (modified Tour’s method) were characterized by higher content of oxygen groups in comparison to method A (Hummers’ method). The flake graphite, characterized by the largest diameter of crystallites, proved to be the most suitable material for the preparation of graphene materials. Reduced graphene oxides obtained from flake graphite are characterized by a greater reduction degree and less amounts of defect .