DETERMINATION OF BASIC CHARACTERISTICS OF PROTECTIVE LAYERS BASED ON POLYMERIC NANOFIBERS
This work focuses on a basic research in developing new class of protective layers for building materials based on polymeric nanofibers. Nonwoven nanotextiles are fibers with diameter spanned from tens to hundreds of nanometers. Thin films consisting of suitable polymer-based nanofibers were prepared using NANOSPIDER equipment. Applied technology is unable to fully guarantee quality (homogeneity, thickness, etc.) of the protective coating. Traditionally used technologies –such as painting or spraying – are not too effective and the separation of protective coating or loosing of protective properties is frequently observed.
Electrospun SiO2 Nanotextiles for Preservation of a Tangible Cultural Heritage
The developing nanotechnology is getting infiltrated into a wide area of industries. A variety of nanotextiles can be produced from different materials (e.g. polymers, SiO2). Their applications are possible in many industrial branches as well as civil engineering. Silica-based nanotextiles can play a fundamental role in civil engineering. The potential utilization of nanotextiles in civil engineering is promising as surface protective layers. Wettability of SiO2 nanotextiles was studied on different thicknesses of samples and were tested under static conditions by determination of the water contact angle. Their water contact angle, which indicates the degree of wetting, was measured using an optical tensiometer.
Inhibition of Mild Steel Corrosion Using L-tryptophan and Synergistic Surfactant Additives
The corrosion inhibition characteristics of nitrogen containing amino acid L-tryptophan on mild steel in 0.1 M HCl solution, in the temperature range of 30-50 o C, was studied by weight loss and potentiodynamic polarization measurements. L-tryptophan significantly reduces the corrosion rates of mild steel; the maximum inhibition efficiency being 83% at 50 o C in presence of inhibitor concentration of 500 ppm. The effect of the addition of very small concentrations of anionic surfactant, sodium dodecyl sulfate (SDS), and of cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), on the corrosion inhibition behavior of L-tryptophan was also studied. The inhibition efficiency (IE) of L-tryptophan significantly improved in presence of both surfactants. The effect of SDS and CTAB on the corrosion inhibition behavior of L-tryptophan appears to be synergistic in nature, the values of synergism parameter being greater than unity. The adsorption of inhibitors on mild steel surface obeyed Langmuir’s adsorption isotherm. The calculated thermodynamic parameters for adsorption reveal a strong interaction between the inhibitors and the mild steel surface. The results obtained by electrochemical studies are consistent with the results of the weight loss measurements. L-tryptophan acts more anodic than cathodic inhibitor.