Functionalization of polyvinylchloride textile surface with thin films of silver oxide by chemical method

A detailed analysis of smart textiles for architectural facades has shown that multifunctional textiles with functional coatings and energy recovery additions can provide suitable design solutions for lightweight, durable, low-cost, sustainable, and multifunctional architectural facades. This is a viable and sustainable construction solution [1]. Textile-based solar thermal energy collectors (TSTEC) are one form of novel flexible solar thermal harvesting product, and one that can widely be applied within the fields of building roofs and facades. The study found that the properties of TSTEC in terms of two-layer textile composition were much more efficient when compared to those, which had other numbers of layers. It was also found that a lower airflow velocity contributed to a higher outlet temperature, and that airflow velocity served to increase useful heat levels. It was further proven that an extension to the wind tunnel was very important when it came to being able to increase the efficiency levels of solar thermal energy conversion [2]. Thin film metal oxides are superior solar light absorbers. Many of the metal oxides are n-type semiconductors. Known p-type oxides include silver (I) oxide. They can be combined into a functional material when deposited on polymeric substrates. The optical band gap for Ag2O ranges from 1.2 eV [3] to 3.4 eV [4] depending on the stoichiometry, structure and physical properties that result from the deposition method. In this study, silver oxide films were synthesised on a polyvinylchloride textile (PVC), and an investigation was carried out into the structural, optical, and mechanical properties of the treated fabric. The chemical deposition method was used to modify the PVC textile surface by means of thin silver oxide films. Prior to the process of depositing the materials, the mechanically roughened surface was pre-treated with two different solutions: thermo-alkaline and thermo-oxidative-acidic [5]. An X-ray diffraction (XRD) analysis was carried out in order to provide a level of understanding in regards to the formation of the silver oxide phase and its crystalline structure following the completion of the reactive thermo-chemical treatment of the prepared samples. The XRD analysis revealed that deposited films exist as polycrystalline mixed-phase material, which is composed of Ag2O, AgO, and metallic Ag. Ultraviolet-visible (UV-Vis) diffuse reflectance spectra were recorded to study the optical properties of deposited films. It was found that Ag-O/PVC composites are direct band gap semiconductors; the optical band gap is 0.89±0.02eV. A determination was made of percentage changes for the fabric thickness, total mass per unit area after modification and tensile, and tear tests were carried out. The results showed that the treatment did not serve to negatively affect the structural properties of the PVC textile, while any relative difference of thickness is negligible. When evaluating the material for tear strength, it was found that after both alkaline and oxidative-acid treatments, no noticeable change in tear strength was observed in the longitudinal and transverse directions of the samples. When analysing the tensile characteristics, it was found that due to thermochemical treatment, the tensile strength of architectural textiles decreased in both directions.