Jānis Zandersons

Application of metal coatings for functionalization of technical fibers and fabrics

The metal coatings in combination with sonochemical and leaching processes are used for nanostructuring and functionalization of glass, flax and hemp fabrics. The leaching is used for nanostructuring sodium alumosilicate K-glass fabrics to obtained silica like fibre with nanoporous structure on surface and in volume. The natural fibres as well as fabrics themselves are porous media. The porous media adsorbs water and content of moisture in fabrics have to be controlled. The metal-coated fabric characterization is an actual problem. Application of metal coatings for the functionalization of technical fibres and fabrics faced with influence of moisture on functional properties, e.g., the impedance of the metal coated K-glass and flax and hemp fabrics have strong dependence of content absorbed water or moisture. Presented studies are on the moisture content determination methodology based on fhermogravimetric analyses and impedance spectroscopy. The leached K-glass fibres have three absorption sites with different kinetic and desorption heat. The flax has more complicated distribution of sorption/desorption sites. The water desorption heatl,3 kJ/g for both type of fabrics in temperature range 30–150 0C is comparable to the water evaporation heat 2,3 kJ/g at 100 0C. For leached K-glass fibre from the isothermal nitrogen sorption/desorption plot the pore volume is up to 7.5 cm3/g. and pore sizes are in range 2-100 nm.

Study the effects of moisture content on the electrical properties of technical textiles by impedance spectroscopy

Application of metal coatings for the functionalization of technical fibres and fabrics faced with influence of moisture on functional properties, e.g., the impedance of the metal coated K-glass fabrics have strong dependence of content absorbed water or moisture. The paper devoted to develop methodology for characterisation functional materials based on fabrics and model for interpretation of the electrical impedance spectra to obtained functional characteristics of technical textile fabrics. Model based on analyses of 3D plot of imaginary part of complex modulus spectra versus sample mass. Methodology helps to control content of adsorbed water in fabric and influence of moisture on the functional characteristics.