Electronic Supplementary Information ( ESI ) Ambient Rutile VO 2 ( R ) Hollow Hierarchitectures with Rich Grain Boundaries from New-State Nsutite-Type VO 2 , Displaying Enhanced Hydrogen Adsorption Behavior
S1. Shape evolution of the new-state VO 2 hollow spherical nanoarchitectures S2. Compositional characterization of the new-state nsutite-type VO 2 precursor S3. Summary XRD patterns of the nsutite-type VO 2 prepared by different chemical reactions S4. Structural determination of new-state VO 2 S5. Calculation details and phase conversion process from the new-state nsutite-type VO 2 to rutile VO 2 (R) S6. Characterization of the GBR-VO 2 (R) hollow hierarchitectures S7. Gas adsorption experiments of different vanadium oxides
Electronic Supplementary Information
Giuseppe Mattioli, 2, ∗ Marcel Risch, Aldo Amore Bonapasta, Holger Dau, and Leonardo Guidoni 2, † Istituto di Struttura della Materia (ISM) del Consiglio Nazionale delle Ricerche, Via Salaria Km 29.5, CP 10, 00016 Monterotondo Stazione, Italy Dept. of Physics, “Sapienza” Università di Roma, P.le A. Moro 2, 00185 Roma, Italy Dept. of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università de L’Aquila, Località Campo di Pile, 67100 L’Aquila, Italy
Experimental investigation of the geotechnical properties and microstructure of lime-stabilized saline soils under freeze-thaw cycling
Abstract The Song-Nen Plain in northeastern China holds one of the three largest expanses of soda saline-alkali soil in the world. Due to its disadvantageous geotechnical properties, the saline soil in this area is unable to meet the needs of construction projects. This study evaluates the stabilizing effect of adding lime to such soils. Specifically, it investigates how the physicochemical and mechanical properties and microstructure of soda saline-alkali soil are altered by lime and how these changes are affected by both freeze-thaw cycling and the duration of curing. The results reveal that adding lime to saline soil transforms clay particles into sand and silt particles and causes the pore size distribution (PSD) to become bimodal, with small-pore and macropore populations. An increase in lime content leads to an increase in the unconfined compressive strength (UCS) but a gradual decrease in both the cation exchange capacity (CEC) and plastic index. Freeze-thaw cycles break up coarse particles and aggregate finer particles, increasing the diameter of macropores and decreasing the USC; however, the effect on specimens with >9% lime is negligible. It is further shown that the geotechnical properties of the soil change immediately after the addition of lime, indicating that the cation exchange reaction takes place very quickly. Furthermore, the pozzolanic reaction leads to an increase in the percentage of sand-sized particles and a decrease in porosity after 28 days of curing. Overall, these results indicate that it is feasible to use lime to improve the engineering properties of soda saline-alkali soil in this area.