State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
Environ Sci Technol. 2020 Jan 7;54(1):517-526. doi: 10.1021/acs.est.9b05335. Epub 2019 Dec 12.
Surface functionalization using two-dimensional (2D) graphene oxide (GO) materials is a promising technique to enhance the biofouling resistance of membranes used in water purification and reuse. However, the role of GO exposure, which is crucial for the contact-mediated toxicity mechanism, has not been well evaluated or elucidated in previous studies. Herein, we employ bioinspired polydopamine chemistry to fabricate GO-functionalized membranes through two strategies: coating and blending. The two types of GO-functionalized membranes displayed comparable roughness, hydrophilicity, water permeability, and solute retention properties but different degrees of GO nanosheet exposure on the membrane surface. When in contact with the model bacterium, , the GO-coated membrane exhibited enhanced biofouling resistance compared to that of the GO-blended membrane, as evidenced by lower viable cells in static adsorption experiments, and lower water flux decline and higher flux recovery in dynamic biofouling experiments. Moreover, the development of biofilm on the GO-coated membrane was also inhibited to a greater extent than on the GO-blended membrane. Taken together, our findings indicate the paramount importance of GO exposure on the membrane surface in conferring antibacterial activity and biofouling resistance, which should be considered in the future design of antibiofouling membranes using 2D nanomaterials.
使用二维（2D）氧化石墨烯（GO）材料进行表面功能化是一种增强用于水净化和再利用的膜的抗生物污染能力的有前途的技术。然而，在以前的研究中，GO 暴露的作用，这对于接触介导的毒性机制至关重要，尚未得到很好的评估或阐明。在此，我们通过两种策略——涂层和共混——利用仿生多巴胺化学来制备 GO 功能化膜。两种类型的 GO 功能化膜具有相似的粗糙度、亲水性、水渗透性和溶质保留性能，但在膜表面上的 GO 纳米片暴露程度不同。当与模式细菌接触时，GO 涂层膜表现出比 GO 共混膜更高的抗生物污染能力，这表现在静态吸附实验中活细胞更少，动态生物污染实验中通量下降更低和通量恢复更高。此外，GO 涂层膜上生物膜的发展也比 GO 共混膜受到更大的抑制。综上所述，我们的研究结果表明，GO 暴露在膜表面上对抗菌活性和抗生物污染能力至关重要，这在未来使用 2D 纳米材料设计抗生物污染膜时应予以考虑。
