Enhancing the Performance of Electrospun Nanofiber Membranes in Water and Wastewater Treatment Processes Using Omniphobic Surface Modification

Abstract

The necessity for advantageous advancements in filtering technology has resulted in limited attention towards emerging materials, specifically nanofiber membranes, for water purification. The issue of organic material and the collection of residual organics in wastewater is a significant challenge since existing treatments like coagulation/flocculation and chlorine treatment have proven insufficient in achieving satisfactory outcomes. Further treatment and disposal steps are required for the additional amount of sludge produced by these methods. The field of nanotechnology has remarkable promise in filtration applications owing to its capacity to fabricate materials with exact structural control to meet specific needs. Membrane distillation (MD) has emerged as a potentially viable method for treating industrial wastewater. However, the existing hydrophobic MD membranes encounter substantial challenges related to wetting, mostly caused by the presence of pollutants often found in wastewater. This work presents a novel approach for the production of a Poly Vinylidene Fluoride - Hexa Fluoro Propylene Electrospun Nanofiber Membrane (PVF-HFP-ENM) that exhibits enhanced resistance to wetting by reduced surface-tension materials. The PVF-HFP-ENM membrane, which possesses an inherent re-entrant structure, has been fluorinated using 1H, 1H, 2H, 2H-Per Fluoro Decyl Trichlorosilane (PFDT) by Vapor Deposition (VD) without the need for surface activation. The fluorinated membrane had exceptional surface omniphobicity, as evidenced by its high contact angles with water and ethanol, measuring 148±0.4° and 120 ± 0.8°, respectively. The fluorinated membrane exhibited exceptional stability regarding omniphobicity and mechanical qualities, even when subjected to extreme circumstances such as ultrasonic disinfection, boiling water, and acidic and base exposure. The present work focuses on utilizing ENM in the context of industrial wastewater treatment and the alteration of nanomembranes to mitigate clogging problems and enhance the efficiency of wastewater treatment processes.