TiO2-decorated NaA zeolite membranes with improved separation stability for pervaporation dehydration of N, N-Dimethylacetamide
TiO2-decorated NaA zeolite membranes with improved separation stability for pervaporation dehydration of N, N-Dimethylacetamide
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DOI：
10.1016/j.memsci.2021.119398
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发表时间：
2021-09
影响因子：
9.5
通讯作者：
Yuting Zhang;Xinfeng Zhu;Sheng-Li Chen;Jinyun Liu;Z. Hong;Jiacheng Wang;Zhi Li;Xuechao Gao;Rongfei Xu;X. Gu
中科院分区：
文献类型：
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作者：
Yuting Zhang;Xinfeng Zhu;Sheng-Li Chen;Jinyun Liu;Z. Hong;Jiacheng Wang;Zhi Li;Xuechao Gao;Rongfei Xu;X. Gu
传统的NaA沸石膜在极性非质子溶剂的渗透蒸发（PV）脱水中保持稳定的水通量是一个巨大的挑战，因为这些溶剂在膜表面的强烈吸附抑制了水的吸附，从而逐渐降低水通量。为了解决这个问题，采用一种简单的表面修饰方法，用溶胶-凝胶衍生的 TiO2 纳米颗粒修饰 NaA 沸石膜的表面，用于 N,N-二甲基乙酰胺 (DMAc) 的 PV 脱水。通过SEM、XRD、XPS、溶剂吸附和水接触角等手段，广泛研究了TiO2前驱体组成对TiO2/NaA沸石复合膜性能和分离性能的影响。结果表明，沸石膜顶部的多孔 TiO2 层不仅阻碍了 DMAc 分子与沸石膜上的钠阳离子之间的静电相互作用，而且允许水渗透而不会造成通量大的损失。 10 wt%水/DMAc混合物在363 K下连续PV脱水24 h后，TiO2/NaA沸石膜的水通量损失最小约为17%，而裸NaA沸石膜在15 h内水通量损失超过95%，表明NaA沸石膜用于DMAc PV脱水的分离稳定性得到有效改善。
It is a great challenge for conventional NaA zeolite membrane to maintain stable water flux in pervaporation (PV) dehydration of polar aprotic solvents because the aggressive adsorption of these solvents on membrane surface restrain water adsorption and thereby reduce water flux gradually. To address this issue, a facile surface modification method was adopted to decorate the surface of NaA zeolite membrane with sol-gel derived TiO2nanoparticles for PV dehydration of N, N-Dimethylacetamide (DMAc). Effect of TiO2precursor composition on properties and separation performance of TiO2/NaA zeolite composite membranes was investigated extensively in terms of SEM, XRD, XPS, solvent adsorption and water contact angle. The results showed that the porous TiO2layer on top of zeolite membrane not only hindered the electrostatic interaction between DMAc molecules and sodium cations from zeolite membrane but also allowed water permeation without large loss in flux. The minimum loss in water flux of TiO2/NaA zeolite membrane was about 17% after continuous PV dehydration of 10 wt% water/DMAc mixture for 24 h at 363 K while that of bare NaA zeolite membrane was over 95% within 15 h, indicating the effective improvement on separation stability of NaA zeolite membrane for PV dehydration of DMAc.