Synthesis of surface modified hydrophobic PTFE-ZnO electrospun nanofibrous mats for removal of volatile organic compounds (VOCs) from air

Abstract

The article reports a two-step synthesis of composite nanofibrous mats of polytetraflouroethylene/zinc oxide (PTFE-ZnO); first, emulsion electrospinning of precursor solution was performed to yield as-spun mats followed by heat treatment at 280 °C. The surface of pure PTFE nanofibrous mats was modified by varying the amount of ZnO loadings in the electrospinning solution from 10 to 20 wt.%. Physiochemical characterization of synthesized mats was performed by FESEM, EDX, AFM, FTIR, Raman, TGA and contact angle goniometry. It was observed that fiber mean diameter decreased from 0.243 ± 15.10 μm to 0.17 ± 30.50 μm, RMS roughness increased from 112 to 627 nm and CA improved from 102.56° to 121.55° with the rise in ZnO content up to 20 wt% compared to the pure PTFE mats. Higher surface area, roughness and hydrophobicity of PTFE-ZnO mats resulted into significantly enhanced adsorption ability of VOCs on their surfaces against three model VOCs, namely, toluene, acetone and formaldehyde. The results have demonstrated that surface adsorption capacity of tested VOCs has considerably increased to 10, 07 and 03 folds respectively for the nanofibrous mats containing 20 wt.% ZnO, compared to pure PTFE mats. Based on these findings, these nanofibrous mats can potentially be used as filters for VOCs and particulate removal from air in the processing industries.