Antibacterial nanocellulose membranes coated with silver nanoparticles for oil/water emulsions separation

The superhydrophilic/underwater superoleophobic nanocellulose-based membranes show great potential in oil/ water emulsion separation. However, nanocellulose composed of polysaccharides inevitably suffered from bacterial erosion during use or storage, resulting in structural damage or reduced separation efficiency. In this work, silver nanoparticles (AgNPs) as effective bactericidal materials are uniformly deposited on tunicate cel-lulose nanocrystals (TCNCs) by in situ hydrothermal reduction of silver nitrate. TCNCs not only act as reducing agents for silver ions, but also work as dispersant and stabilizers of AgNPs. Nanocomposite membranes are fabricated by vacuum-assisted filtrating of AgNPs@TCNC suspension, which exhibit nanoporous structure, superhydrophilicity, and underwater superoleophobicity. These membranes could efficiently separate oil/water microemulsion with water flux (>324 L m(-2) h(-1) bar(-1)) and oil rejection (>99%). Importantly, these membranes show excellent antibacterial efficacy against E. coli and S. aureus, benefiting to their long-term use and storage.

Automated summary

This study developed a superhydrophilic/underwater superoleophobic nanocellulose-based membrane by depositing silver nanoparticles on tunicate cellulose nanocrystals. These membranes exhibit nanoporous structure, high separation efficiency for oil/water emulsion, and excellent antibacterial efficacy.