Abstract The objective of this study is to investigate the interaction between graphene oxide (GO) laminate and salt solutions. The well-aligned GO laminates are distributed on the top surface of a polyvinylidene fluoride-polyacrylic acid (PVDF-PAA) microporous layer via vacuum filtration. The PVDF-PAA layer is formed after being cast on a non-woven support and immersed in a water coagulation bath. We illustrate herein how the inter-layer spacing of the GO laminate membrane is varied due to contact with salt solutions or water, which results in tunable ionic sieving effect. It is assumed that the water permeation through the GO composite membrane follows a modified Hagen-Poiseuille's law. The GO inter-layer spacing is calculated, and this spacing is shrunken to 2.8 nm in the presence of MgSO4 and enlarged to 6.1 nm with Na2SO4 from the initial 4.8 nm of water-swollen GO. The permeance values of the filtrate from Na-solutions are unexpectedly higher than those of pure water. The strong GO-Mg2+ interaction causes the surface zeta potential toward a neutral charge, which results in low rejections (

中文翻译：

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氧化石墨烯-阳离子相互作用：响应于各种盐溶液的层间距和 zeta 电位变化

摘要 本研究的目的是研究氧化石墨烯 (GO) 层压板与盐溶液之间的相互作用。排列良好的 GO 层压板通过真空过滤分布在聚偏二氟乙烯-聚丙烯酸 (PVDF-PAA) 微孔层的顶面上。PVDF-PAA层是在无纺布载体上浇铸并浸入水凝固浴后形成的。我们在此说明了 GO 层压膜的层间距如何因与盐溶液或水的接触而变化，从而导致可调节的离子筛分效果。假设水通过 GO 复合膜的渗透遵循修正的哈根-泊肃叶定律。计算出 GO 层间距，在 MgSO4 存在下，该间距缩小至 2.8 nm，并放大至 6。1 nm 与 Na2SO4 从最初的 4.8 nm 水溶胀 GO。钠溶液滤液的渗透率值出乎意料地高于纯水的渗透率值。强烈的 GO-Mg2+ 相互作用导致表面 zeta 电位趋向于中性电荷，从而导致低排斥（