Chae Hee-Ro, Kim In-Chul, Kwon Young-Nam
Center for Membrane, Advanced Green Chemical Materials Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea.
School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea.
Materials (Basel). 2021 Jun 8;14(12):3151. doi: 10.3390/ma14123151.
In this study, the effect of graphene oxide nanosheets (GONs) embedded in a thin-film composite (TFC) polyamide (PA) membrane on the acid resistance of the membrane was investigated by comparison with the effect of oxidized single-walled carbon nanotubes (o-SWNTs). Both GONs and o-SWNTs increased the hydrophilicity of the membranes and caused the formation of ridges and clustered bumps on the surfaces, resulting in slightly improved water permeability. However, the o-SWNTs-embedded membrane did not show a difference in acid resistance depending on the concentration of embedded material, but the acid resistance of the GONs-embedded membrane increased with increasing concentration. The acid resistance of the GONs-embedded membranes appears to be mainly due to the barrier effect caused by the nanosheet shape of the GONs along with a sacrificial role of the PA layer protruded by the addition of GONs and the decrease of acid reaction sites by the hydrogen bonding between GONs and PA. When the TFC PA membrane was prepared with a high amount (300 ppm) of the GONs without considering aggregation of GONs, membrane selectivity exceeding 95% was maintained 4.7 times longer than the control TFC membrane. This study shows that the acid resistance can be enhanced by the use of GONs, which give a barrier effect to the membrane.
在本研究中，通过与氧化单壁碳纳米管（o-SWNTs）的作用进行比较，研究了嵌入在薄膜复合（TFC）聚酰胺（PA）膜中的氧化石墨烯纳米片（GONs）对膜耐酸性的影响。GONs和o-SWNTs均提高了膜的亲水性，并导致膜表面形成脊状和簇状凸起，从而使水渗透性略有提高。然而，嵌入o-SWNTs的膜的耐酸性并未因嵌入材料浓度的不同而表现出差异，但嵌入GONs的膜的耐酸性随浓度增加而提高。嵌入GONs的膜的耐酸性似乎主要归因于GONs的纳米片形状所引起的阻挡效应，以及添加GONs后突出的PA层的牺牲作用，以及GONs与PA之间的氢键作用导致酸性反应位点的减少。当在不考虑GONs聚集的情况下用大量（300 ppm）的GONs制备TFC PA膜时，膜的选择性超过95%的保持时间比对照TFC膜长4.7倍。本研究表明，使用GONs可增强膜的耐酸性，GONs对膜具有阻挡作用。
