Mussel-/diatom-inspired silicified membrane for high-efficiency water remediation

Water purification polymeric membranes are critical for defending water safety and mitigating water crisis stress. They are hampered by membrane hydrophobicity for undesirable filtration performance and troublesome fouling issues. Membrane interface hydrophilization with good hydrophilicity and well-behaved adhesion are highly desired. Here, inspired by bio-protein adhesives and silicified diatom shells, a facile one-step biomimetic silicification method by tannic acid and 3-glycidyloxypropyltrimethoxysilane was explored at ambient conditions. The silicification method is green and cost-effective. The as-decorated membranes boosted hydrophilicity with outstanding rigid test tolerance. The silicification conditions could be regulated by resultant surface chemistry. The hydrophilized microfiltration membrane realized cyclable oily emulsion purification with flux over 2580 L m⁻² h⁻¹ and oil repulsion over 99.2%. It also demonstrates outstanding repulsion to crude oil. The as-decorated ultrafiltration membrane displayed an improved protein interception (BSA interception above 94.1%, water flux about 424 L m⁻² h⁻¹) and antifouling (73.2% enhancement) capacity. The as-presented biomimetic silicification hydrophilization strategy could potentially promote the development of high-performance water purification membranes and efficient energy-water nexus system.