A superhydrophilic and robust fabric, featuring self-assembled layers of chitosan and carbon nanotubes, facilitates high-throughput oil–water separation

Abstract

Petroleum pollution and industrial emissions of organic pollutants have become significant issues affecting both ecological and human living environments. High-performance oil–water separation membranes, due to their advantages such as low cost, environmental friendliness, and ease of operation, hold vast application prospects. Therefore, the development of efficient oil–water separation membranes is crucial. We propose a clever approach involving the synergistic self-assembly of chitosan (CS) and hydroxylated multi-walled carbon nanotubes (MWCNTs) on cotton fabric to construct a rough structure. Combined with hydrophilic modification using polyvinyl alcohol (PVA), not only does this enhance wettability, but it also addresses challenges related to mechanical strength and dispersibility of cotton fabric. The resulting CMF-PVA fabric performs well under challenging conditions, exhibiting excellent separation efficiency and permeance. Particularly noteworthy is that CMF-PVA achieves separation efficiencies exceeding 99.33 % for various organic substances, with a water flux reaching 35,476.52 L m−2 h−1 and a surfactant-stabilized emulsion permeance of 1199.0 L m−2 h−1·bar−1. Furthermore, CMF-PVA demonstrates outstanding mechanical durability under harsh conditions and excellent acid-base resistance. This method harnesses the inherent properties of CS and MWCNT self-assembly while enhancing the material's applicability on cotton fabric through hydrophilic modification. CMF-PVA fabric is poised to enhance selectivity, efficiency, anti-pollution properties, and accessibility in oil–water separation technology.