Electro-physical properties of jute fabrics in a condition of high humidity - Effect of fabric chemical composition and coating with Cu-based nanoparticles

The electro-physical properties of raw and chemically modified jute fabrics were studied as complex phenomena of the interaction between the fabrics’ chemical composition, crystallinity, moisture sorption, COOH group content, structural characteristics, and frequency of the electric field. At 80% relative air humidity, all chemically modified jute fabrics have 38–179% and 1.7–5.4 times higher dielectric loss tangent and effective relative dielectric permeability compared to unmodified, respectively. To further improve these properties, fabrics were treated with CuSO4 and Cu-based nanoparticles were in situ synthesized on their surface by reduction. A few single Cu-based nanoparticles were observed across the alkali modified fabric’s surface, while single and agglomerated nanoparticles were distributed over the oxidatively modified fabric’s surface. No matter whether metallic Cu or copper oxide (Cu2O or CuO) nanostructures (or their mixtures) are synthesized (proven by XRD), excellent fabrics’ effective relative dielectric permeability is guaranteed. In other words, during the exploitation in specific conditions contributing to copper reduction, the jute fabrics will be able to store 21–163 times more energy from an external electric field than before the exploitation, which further extended their lifetime. On the other hand, with increasing the total content of Cu after the reduction and formation of single and agglomerated Cu-based nanoparticles, the movement of jute structural components’ molecules becomes difficult resulting in lower energy dissipation within the chemically modified than within unmodified fabric. Applied chemical modification and coating with Cu-based nanoparticles enables designing fabrics with predictable electro-physical properties, which is very important from the application point of view.