Department of Chemical and Biological Engineering and RENEW Institute, The State University of New York, University at Buffalo, Buffalo, New York 14260, United States.
Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
ACS Appl Mater Interfaces. 2023 Jul 5;15(26):32066-32073. doi: 10.1021/acsami.3c07089. Epub 2023 Jun 21.
Two-dimensional (2D) materials provide a great opportunity for fabricating ideal membranes with ultrathin thickness for high-throughput separation. Graphene oxide (GO), owing to its hydrophilicity and functionality, has been extensively studied for membrane applications. However, fabrication of single-layered GO-based membranes utilizing structural defects for molecular permeation is still a great challenge. Optimization of the deposition methodology of GO flakes could offer a potential solution for fabricating desired nominal single-layered (NSL) membranes that can offer a dominant and controllable flow through structural defects of GO. In this study, a sequential coating methodology was adopted for depositing a NSL GO membrane, which is expected to have no or minimum stacking of GO flakes and thus ensure GO's structural defects as the major transport pathway. We have demonstrated effective rejection of different model proteins (bovine serum albumin (BSA), lysozyme, and immunoglobulin G (IgG)) by tuning the structural defect size via oxygen plasma etching. By generating appropriate structural defects, similar-sized proteins (myoglobin and lysozyme; molecular weight ratio (MWR): ∼1.14) were effectively separated with a separation factor of ∼6 and purity of 92%. These findings may provide new opportunities of using GO flakes for fabricating NSL membranes with tunable pores for applications in the biotechnology industry.
二维（2D）材料为制造超薄厚度的高通量分离理想膜提供了巨大机会。氧化石墨烯（GO）由于其亲水性和功能性，已被广泛研究用于膜应用。然而，利用结构缺陷制造单层 GO 基膜以进行分子渗透仍然是一个巨大的挑战。优化 GO 薄片的沉积方法可能为制造所需的标称单层（NSL）膜提供一种潜在的解决方案，该膜可以通过 GO 的结构缺陷提供主要和可控的流动。在这项研究中，采用了顺序涂层方法来沉积 NSL GO 膜，预计该膜中没有或最小的 GO 薄片堆叠，从而确保 GO 的结构缺陷作为主要传输途径。我们通过氧等离子体蚀刻来调节结构缺陷尺寸，成功地对不同的模型蛋白（牛血清白蛋白（BSA）、溶菌酶和免疫球蛋白 G（IgG））进行了有效的截留。通过产生适当的结构缺陷，大小相似的蛋白（肌红蛋白和溶菌酶；分子量比（MWR）：∼1.14）可以有效地分离，分离因子约为 6，纯度约为 92%。这些发现可能为使用 GO 薄片制造具有可调孔径的 NSL 膜提供新的机会，可应用于生物技术行业。
