Tunable interlayer spacing of composite graphene oxide-framework membrane for acetic acid dehydration
Tunable interlayer spacing of composite graphene oxide-framework membrane for acetic acid dehydration
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DOI：
10.1016/j.carbon.2017.08.019
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发表时间：
2017-10-01
期刊：
影响因子：
10.9
通讯作者：
Lai, Juin-Yih
中科院分区：
文献类型：
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作者：
Lecaros, Rumwald Leo G.;Mendoza, Gregory Emmanuel J.;Lai, Juin-Yih
采用微量聚乙烯醇（PVA）交联氧化石墨烯（GO）纳米片制备了具有珍珠质结构的氧化石墨烯-骨架（GOF）复合膜。PVA提供了GO悬浮液粘度的额外增加，这使得大面积复合GOF膜的溶液浇铸成为可能。将该膜用于渗透汽化分离醋酸-水混合物。ATR-FTIR和XPS分析证实GO与PVA之间形成了醚键形式的共价键。这影响了水接触角的变化，其中它从40.8度（原始GO）增加到62.7度（GO-PVA（8wt%））。X射线衍射分析表明，由于PVA的插层作用，GOF的d-间距比GO大。GO层从干态到湿态的d-间距具有2.59埃的差异，但PVA的添加将差异降低至0.38埃。GO和PVA之间新形成的共价键可能抑制d间距的拉伸。结果表明，该复合材料的层间距可调，且能有效地防止溶胀。GO-PVA（8wt%）复合膜具有较短的膜间距，在80 ℃下具有优异的渗透汽化性能，渗透通量为463.9g·m（-2）·h（-1），渗透液中水含量为97.7%。(C)2017爱思唯尔有限公司版权所有
Minute amount of poly(vinyl alcohol) (PVA) was used to cross-link graphene oxide (GO) nanosheets to prepare composite graphene oxide-framework (GOF) membranes with a nacre-like structure. The PVA provided additional increase in viscosity of GO suspension which made the solution casting of a large-area composite GOF membrane possible. The membranes were applied to separate an acetic acid-water mixture through pervaporation. The ATR-FTIR and XPS analyses confirmed the covalent bonding between GO and PVA as ether bonds were formed. This influenced the changes in water contact angle where it increased from 40.8 degrees (pristine GO) to 62.7 degrees (GO-PVA(8wt%)). X-ray diffraction showed that d-spacing of GOF was higher than GO due to the intercalation of PVA. The d-spacing of GO layer from dry to wet state has a difference of 2.59 angstrom but addition of PVA lowered the difference to 0.38 angstrom. The newly formed covalent bonds between GO and PVA might suppressed the stretching of d-spacing. It shows that the swelling was prevented and the interlayer spacing can be tuned. The composite GO-PVA(8wt%) membrane has a short d-spacing and provided an outstanding pervaporation performance at 80 degrees C with a permeation flux of 463.9 g m(-2) h(-1) and water concentration in permeate of 97.7%. (C) 2017 Elsevier Ltd. All rights reserved.