Photografting Graphene Oxide to Inert Membrane Materials to Impart Antibacterial Activity

Abstract

Surface modification with bactericides is a promising approach to imparting membrane materials with biofouling resistance. However, chemical modification of membranes made from inert materials, such as polyvinylidene fluoride (PVDF) and polysulfone, is challenging because of the absence of reactive functional groups on these materials. In this study, we develop a facile procedure using benzophenone as an anchor to graft biocidal graphene oxide (GO) to chemically inactive membrane materials. GO nanosheets are first functionalized with benzophenone through an amide coupling reaction. Then, benzophenone-functionalized GO nanosheets are irreversibly grafted to the inert membrane surfaces via benzophenone-initiated cross-linking under ultraviolet irradiation. The binding of GO to the membrane surface is confirmed by scanning electron microscopy and Raman spectroscopy. When exposed to a model bacterium (Escherichia coli), GO-functionalized PVDF and polysulfone membranes exhibit strong antibacterial activity, reducing the number of viable cells by 90% and 75%, respectively, compared to the number with the pristine membranes. Notably, this bactericidal effect is imparted to the membranes without compromising membrane permeability or solute retention properties. Our results highlight the potential application of benzophenone chemistry in membrane surface modification as well as its promise in developing antimicrobial surfaces for a variety of environmental applications.

Two-Dimensional Ti3C2Tx MXene/GO Hybrid Membranes for Highly Efficient Osmotic Power Generation

“…Thus, in terms of membranes, the adhesive interaction between the E. coli and the membrane surface relationship to the membrane surface properties is a potential explanation for the CFU abundance difference . The improved surface hydrophilicity and smoother surface roughness arising from the increased GO loading enabled the d -Ti 3 C 2 T x /GO-45 membrane to become less prone to the fouling induced by hydrophobic E.…”

“…Thus, in terms of membranes, the adhesive interaction between the E. coli and the membrane surface relationship to the membrane surface properties is a potential explanation for the CFU abundance difference. 69 The improved surface hydrophilicity and smoother surface roughness arising from the increased GO loading enabled the d-Ti 3 C 2 T x /GO-45 membrane to become less prone to the fouling induced by hydrophobic E. coli cells. The enhanced antibacterial performance of the membrane with a higher GO content could increase the membrane biofouling potential by restricting bacterial attachment and biofilm formation on the membrane surface.…”

Precisely Engineered Photoreactive Titanium Nanoarray Coating to Mitigate Biofouling in Ultrafiltration

“…To determine antibacterial activity, the membrane samples were exposed to a bacterial suspension (10 8 cfu mL −1 ) for 3 h at room temperature, as previously reported. 34 After discarding the bacterial suspension, the membranes were each transferred into 5 mL of saline solution and sonicated for 5 min in an ultrasonic bath (26 W L −1 , FS60 Ultrasonic Cleaner) to detach the bacteria from the membrane surface. Three separate diluted solutions of each recovered solution were prepared at 10, 100, and 1000 times dilution factors.…”

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“…This system showed high antimicrobial efficacy against E. coli because of the chemical oxidation and physical disruption abilities of the GO nanosheets. [ 83 ]…”