Zang Yushi, Peek Alex, Shin Yongsoon, Gotthold David, Hinds Bruce J
Department of Material Science and Engineering, University of Washington, Seattle, WA 98105, USA.
Pacific Northwest National Laboratory, Richland, WA 99352, USA.
Membranes (Basel). 2021 Apr 26;11(5):317. doi: 10.3390/membranes11050317.
Graphene oxide (GO) is a promising membrane system for chemical separation applications due to its 2-D nanofluidics properties and an ability to control interplanar spacing for selectivity. The permeance of water, methanol (MeOH) and isopropyl alcohol (IPA) through 5 µm thick membranes was found to be 0.38 ± 0.15, 0.33 ± 0.16 and 0.42 ± 0.31 LMH/bar (liter/m·h·bar), respectively. Interestingly, the permeance of a water-alcohol mixture was found to be dramatically lower (~0.01 LMH/bar) than any of its components. Upon removing the solvent mixture, the transmembrane flux of the pure solvent was recovered to near the original permeance. The interlayer space of a dried GO membrane was found to be 8.52 Å, which increased to 12.19 Å. 13.26 Å and 16.20 Å upon addition of water, MeOH and IPA. A decrease in d-space, about 2 Å, was consistently observed when adding alcohol to water wetted GO membrane and an optical color change and reduction in permeance. A newly proposed mechanism of a partial reduction of GO through a catalytic reaction with the water-alcohol mixture is consistent with experimental observations.
氧化石墨烯（GO）因其二维纳米流体特性以及能够控制层间距以实现选择性，是一种用于化学分离应用的有前景的膜系统。发现水、甲醇（MeOH）和异丙醇（IPA）透过5微米厚膜的渗透率分别为0.38±0.15、0.33±0.16和0.42±0.31 LMH/bar（升/米·小时·巴）。有趣的是，发现水 - 醇混合物的渗透率显著低于其任何一种组分（约0.01 LMH/bar）。除去溶剂混合物后，纯溶剂的跨膜通量恢复到接近原始渗透率。发现干燥的GO膜的层间间距为8.52 Å，加入水、MeOH和IPA后分别增加到了12.19 Å、13.26 Å和16.20 Å。当向水润湿的GO膜中加入醇时，始终观察到d - 间距减小约2 Å，同时出现光学颜色变化和渗透率降低。通过与水 - 醇混合物的催化反应对GO进行部分还原的新提出机制与实验观察结果一致。
