Lv Xing-Bin, Xie Rui, Ji Jun-Yi, Liu Zhuang, Wen Xiao-Yu, Liu Lu-Yue, Hu Jia-Qi, Ju Xiao-Jie, Wang Wei, Chu Liang-Yin
School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China.
State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China.
ACS Appl Mater Interfaces. 2020 Dec 16;12(50):56269-56280. doi: 10.1021/acsami.0c15178. Epub 2020 Dec 2.
Graphene oxide (GO) membranes have shown enormous promise in desalination and molecular/ionic sieving. However, the instability of GO membranes in aqueous solutions seriously hinders their practical applications. Herein, we report a novel and simple strategy to fabricate stable GO membranes in water-based environments through the insertion of various metal cations from metal foils (., copper (Cu), iron (Fe), nickel (Ni), and zinc (Zn) foils) and natural deposition. Based on the cation-π, coordination, and electrostatic interaction between metal cations and GO nanosheets, the aqueous stability and mechanical strength of the membranes are significantly improved. The permeation rates for acetone, toluene, and -xylene molecules across the GO membrane cross-linked by copper ions with a deposition time of 24 h are 0.966, 0.074, and 0.100 mol m h, respectively. Moreover, this membrane displays excellent separation performance, and the separation factor of K/Mg is up to 68.8 in mono-/multivalent metal cation sieving, which indicate the effective molecular/ionic sieving performance. Meanwhile, the ionic sieving of the GO membrane cross-linked by copper ions has excellent repeatability and long-term stability. The versatility of this natural deposition strategy to fabricate GO membranes cross-linked by metal cations is investigated by using Fe foil, Zn foil, and Ni foil as well as other porous substrates such as polyvinylidene fluoride (PVDF), polyethersulfone (PES), and nylon membranes and filter paper. This fabrication strategy also enables low-cost preparation of large-area GO membranes. Therefore, GO membranes cross-linked by metal cations and prepared by this simple metal cation incorporation strategy have large potential application for molecular/ionic sieving in various solution systems.
氧化石墨烯（GO）膜在海水淡化和分子/离子筛分方面展现出了巨大的潜力。然而，GO膜在水溶液中的不稳定性严重阻碍了它们的实际应用。在此，我们报道了一种新颖且简单的策略，通过从金属箔（如铜（Cu）、铁（Fe）、镍（Ni）和锌（Zn）箔）中插入各种金属阳离子并进行自然沉积，在水基环境中制备稳定的GO膜。基于金属阳离子与GO纳米片之间的阳离子-π、配位和静电相互作用，膜的水稳定性和机械强度得到了显著提高。丙酮、甲苯和对二甲苯分子透过沉积时间为24小时的铜离子交联GO膜的渗透率分别为0.966、0.074和0.100 mol m⁻² h⁻¹。此外，该膜表现出优异的分离性能，在单/多价金属阳离子筛分中K/Mg的分离因子高达68.8，这表明其具有有效的分子/离子筛分性能。同时，铜离子交联的GO膜的离子筛分具有出色的重复性和长期稳定性。通过使用铁箔、锌箔和镍箔以及其他多孔基材（如聚偏二氟乙烯（PVDF）、聚醚砜（PES）、尼龙膜和滤纸），研究了这种通过自然沉积策略制备金属阳离子交联GO膜的通用性。这种制备策略还能够低成本制备大面积的GO膜。因此，通过这种简单的金属阳离子掺入策略制备的金属阳离子交联GO膜在各种溶液体系中的分子/离子筛分方面具有巨大的潜在应用价值。
