Department of Desalination and Water Treatment, Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research , Ben-Gurion University of the Negev , Sede-Boqer Campus , Midreshet Ben Gurion 84990 , Israel.
Center for Environmental Science and Engineering (CESE) , Indian Institute of Technology Bombay , Powai, Mumbai 400076 , India.
ACS Appl Mater Interfaces. 2019 Mar 20;11(11):10914-10921. doi: 10.1021/acsami.9b00510. Epub 2019 Mar 6.
Graphene nanomaterials can feature both superb electrical conductivity and unique physical properties such as extreme surface wettability, which are potentially applicable for many purposes including water treatment. Laser-induced graphene (LIG) is an electrically conductive three-dimensional porous carbon material prepared by direct laser writing on various polymers in ambient conditions with a CO laser. Low-fouling LIG coatings in water technology have been reported; however, the mechanical strength and the separation properties of LIG-coated membranes are limited. Here, we show mechanically robust electrically conductive LIG-poly(vinyl alcohol) (PVA) composite membranes with tailored separation properties suitable for ultrafiltration processes. PVA has outstanding chemical and physical stability with good film-forming properties and is a biocompatible and nontoxic polymer. Compared to LIG-coated filters, the PVA-LIG composite membrane filters exhibited up to 63% increased bovine serum albumin rejection and up to ∼99.9% bacterial rejection, which corresponded well to the measured molecular weight cutoff ∼90 kDa. Compared to LIG fabricated on a polymer membrane control, the composite membranes showed similar excellent antifouling properties including low protein adsorption, and the antibiofilm effects were more pronounced at lower PVA concentrations. Notably for the antibacterial capabilities, the LIG-supporting layer maintained its electrical conductivity and a selected LIG-PVA composite used as electrodes showed complete elimination of mixed bacterial culture viability and indicated that the potent antimicrobial killing effects were maintained in the composite. This work demonstrates that the use of LIG for practical industrial filtration applications is possible.
石墨烯纳米材料具有优异的导电性和独特的物理性能，如极端的表面润湿性，这使其在水处理等许多领域都具有潜在的应用价值。激光诱导石墨烯（LIG）是一种在环境条件下通过 CO 激光直接在各种聚合物上进行激光写入制备的导电三维多孔碳材料。已经报道了在水技术中具有低污染性的 LIG 涂层；然而，LIG 涂层膜的机械强度和分离性能有限。在这里，我们展示了具有机械强度和导电性能的 LIG-聚乙烯醇（PVA）复合膜，具有可定制的分离性能，适用于超滤过程。PVA 具有出色的化学和物理稳定性，具有良好的成膜性能，是一种生物相容性和无毒的聚合物。与 LIG 涂层过滤器相比，PVA-LIG 复合膜过滤器的牛血清白蛋白截留率提高了 63%，细菌截留率提高了约 99.9%，这与测量的分子量截止值约 90 kDa 相符。与聚合物膜控制上的 LIG 制造相比，复合膜表现出类似的优异的抗污染性能，包括低蛋白质吸附，并且在较低的 PVA 浓度下，抗生物膜的效果更加明显。值得注意的是，对于抗菌能力，支撑层的 LIG 保持其导电性，并且选择的 LIG-PVA 复合用作电极可完全消除混合细菌培养物的活力，并表明复合膜中的杀菌效果得以保持。这项工作表明，LIG 可用于实际的工业过滤应用。
