Development of novel nanoporous hexagonal tungsten oxide membrane for separation of water/acetic acid mixtures via pervaporation
Development of novel nanoporous hexagonal tungsten oxide membrane for separation of water/acetic acid mixtures via pervaporation
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DOI：
10.1016/j.memsci.2020.118860
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发表时间：
2021-01-18
影响因子：
9.5
通讯作者：
Ichino, Ryoichi
中科院分区：
文献类型：
--
作者：
Kunishi, Hiroto;Hagio, Takeshi;Ichino, Ryoichi
制备了一种用于水/醋酸(H2O/ACoH)分离的新型纳米孔六方氧化钨(NP-h-WO_3)膜。H-WO_3在c面上的纳米孔比H_2O分子大，但比ACoH分子小，因此应该可以有效地分离它们。此外，h-WO_3在酸性(pH<；4)中表现出很高的稳定性。因此，c轴取向的NP-h-WO_3膜在分离H2O/ACoH混合物方面具有广阔的应用前景。在这样的背景下，我们首次报道了在含有乙酸乙酯的前驱体溶液中，通过水热法在多孔陶瓷载体上合成c平面取向的致密NP-HWO(3)膜。ACoH的存在和前驱体溶液中Na2WO4的浓度是影响晶体生长和沿c面择优取向的关键因素。较高的Na2WO4浓度是获得高度c平面取向的膜所必需的。因此，在载体表面预包覆无定形WO_3晶种，然后在Na2O/WO_3/ACoH/H_2O(1/1/0.88/201)(1/1/0.88/201)的前驱体溶液中于180℃下水热合成24 h，可制得致密的c平面取向的NP-h-WO_3膜。在80℃下对H2O/ACoH混合物(10/90(w/w))进行渗透汽化时，所制得的膜的最大分离系数为42.6。
A novel nanoporous hexagonal tungsten oxide (NP-h-WO3) membrane was developed for separating water/acetic acid (H2O/AcOH) mixtures. The nanopores on the c-plane of h-WO3 are larger than H2O molecules and smaller than AcOH molecules and thus should allow for their effective separation. Moreover, h-WO3 exhibits high stability in acids (pH < 4). Therefore, c-axis-aligned NP-h-WO3 membranes are promising for the separation of H2O/AcOH mixtures. Given this background, we report, for the first time, the synthesis of c-plane-aligned dense NP-hWO(3) membranes on porous ceramic supports via the hydrothermal method using a precursor solution containing AcOH. The presence of AcOH and the concentration of Na2WO4 in the precursor solution are the key factors affecting crystal growth and alignment along the c-plane. A high Na2WO4 concentration is necessary for obtaining membranes with a high degree of c-plane alignment. Thus, dense, c-plane-aligned NP-h-WO3 membranes could be fabricated by precoating the support with amorphous WO3 seeds and subsequent hydrothermal synthesis in a precursor solution of Na2O/WO3/AcOH/H2O (1/1/0.88/201) at 180 degrees C for 24 h. The fabricated membranes exhibited a maximum separation factor of 42.6 during the pervaporation of a H2O/AcOH mixture (10/90 (w/w)) at 80 degrees C. Thus, these NP-h-WO3 membranes are highly suited for H2O/AcOH separation.