Fabrication of robust and sustainable superhydrophobic cotton fabrics via surface micro-dissolve method for oil/water separation

The preparation of durable super-hydrophobic cotton fabrics (CFs) poses a significant challenge for oil–water separation, primarily due to nanoparticle loss and the utilization of toxic auxiliaries. This study proposes a sustainable method for creating superhydrophobic CFs. Initially, CFs are treated with a mixture of NaOH and urea at low temperatures to enhance surface roughness while preserving mechanical integrity. Subsequently, hexadecyl trimethoxysilane (HDTMS) and butane tetracarboxylic acid (BTCA) are applied to reduce fiber surface energy. This combined approach results in CFs with outstanding superhydrophobic properties, boasting a water contact angle of up to 155°, surpassing nanoparticle-based surfaces. Furthermore, these fabrics exhibit remarkable mechanical and chemical stability, along with enduring washing durability. Notably, they demonstrate effective self-cleaning abilities in the presence of liquid contaminants and excellent oil/water separation performance with a high separation efficiency. The developed CFs hold promise for diverse applications in both household and industrial settings.