PDA-assisted one-pot fabrication of bioinspired filter paper for oil–water separation

Abstract

Inspired by the robust and durable adhesion of mussels, highly hydrophobic filter paper was fabricated by a polydopamine (PDA)-assisted one-pot procedure using silica nanoparticles and silane coupling agent (hexadecyltrimethoxysilane, HDTMS) as coating materials at ambient temperature. The surface chemistry, morphology, and hydrophobicity of the coated filter paper were measured by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscope, scanning electron microscopy, and water contact angle. The capacity, durability, and recyclability of the coated filter paper were evaluated by the separation of oil–water mixtures and emulsions. The coated filter paper is highly hydrophobic with a water contact angle of > 130°. The coatings with enhanced adhesion to the substrate resisted mechanical abrasion without significant loss of hydrophobicity, which suggested that PDA plays a crucial role in improving the adhesion of silica nanoparticles to the paper surface. The coated filter paper showed high oil–water separation efficiency up to 95%, and maintained high hydrophobicity after recycling over 10 cycles. The coated filter paper that is based on a simple, low cost, and environmentally friendly procedure exhibits potential for applications in oil-recovery and oil–water separation materials.