Attachment of silver nanoparticles (AgNPs) onto thin-film composite (TFC) membranes through covalent bonding to reduce membrane biofouling

• Published in: Journal of membrane science Vol. 441; pp. 73 - 82
• Main Authors: Yin, Jun, Yang, Yu, Hu, Zhiqiang, Deng, Baolin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2013; Elsevier
• Subjects: Anti-biofouling; anti-infective agents; Antiinfectives and antibacterials; Applied sciences; artificial membranes; Biofouling; Bonding; chemical bonding; Composites; Covalent bonding; cysteamine; energy; energy-dispersive X-ray analysis; Escherichia coli; Exact sciences and technology; Forms of application and semi-finished materials; Grafting; leaching; Membranes; nanosilver; permeability; Polyamide; polyamides; Polymer industry, paints, wood; Rejection; Scanning electron microscopy; Silver; Silver nanoparticles; sodium chloride; spectroscopy; Technology of polymers; Thin films; Thin-film composite; Thiol group; transmission electron microscopy; X-radiation; Thiol group; Polyamide; Covalent bonding; Anti-biofouling; Thin-film composite; Silver nanoparticles; Thiol; Nylon; Nanoparticle; Transition metal; Antimicrobial agent; Composite material; Thin film; Silver; Biofouling; Membrane
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2013.03.060

Membrane biofouling has a negative impact on the membrane treatment performance. Silver nanoparticles (AgNPs) are well-known antimicrobial agent. Herein, AgNPs with approximately 15nm in diameter were effectively attached to the surface of polyamide (PA) thin-film composite (TFC) membrane via covalent bonding, with cysteamine as a bridging agent. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and cross-sectional transmission electron microscopy (TEM) studies all showed the immobilization of AgNPs. Compared with the pristine TFC membrane, thiol-terminated membrane (TFC–SH) and AgNPs grafted membrane (TFC-S–AgNPs) both showed a higher water flux with slightly lower salt rejection. At a constant transmenbrane pressure of 300psi, the water permeability of TFC–SH, TFC-S–AgNPs, and control TFC membranes was 70.6±0.5, 69.4±0.3, and 49.8±1.7L/m2h, respectively, while NaCl rejection was 93.4±0.1%, 93.6±0.2%, and 95.9±0.6%, respectively. TFC-S–AgNPs had an improved antibacterial ability to inhibit E. coli growth. The silver leaching from the TFC-S–AgNPs membrane surfaces was minimal, as tested by both batch and flow-through methods. The results successfully demonstrated that AgNPs could be grafted onto TFC via chemical bonding, leading towards the development of an advanced functional TFC membrane with anti-biofouling properties. •AgNPs around 15nm in diameter were synthesized via chemical reduction.•AgNPs were effectively attached to the membrane surface via covalent bonding.•Effects of grafting conditions on membrane performance.•Silver ions releases were assessed via both batch and flow-through experiments.•Biofilm growth test was carried out on a drip flow biofilm reactor.