Effect of trace amounts of water on organic solvent transport through gamma-alumina membranes with varying pore sizes.
Effect of trace amounts of water on organic solvent transport through gamma-alumina membranes with varying pore sizes.
复制标题
微量水对有机溶剂通过不同孔径的γ-氧化铝膜传输的影响。
DOI：
10.1021/la0364237
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
D. Blank
中科院分区：
文献类型：
--
作者：
S. R. Chowdhury;K. Keizer;J. E. ten Elshof;D. Blank
研究了甲苯和正己烷在不同孔径γ -氧化铝膜中的输运行为。结果表明，疏水己烷和甲苯在膜孔径为3.5 nm时的渗透率都符合达西定律。在这些溶剂中存在5-8 × 10（-4）的摩尔水分数，导致γ -氧化铝层的渗透率降低2-4倍，这取决于孔径大小。一般来说，己烷的渗透率比甲苯低。此外，在有水存在的情况下，诱导净液体流过膜的最小施加压力为0.5-1.5 bar。这些现象被解释为水在小于某一临界直径的膜孔中的毛细凝结。这被认为会导致这些孔的运输被严重阻塞，从而使膜的有效扭曲度增加，以运输疏水溶剂。
The transport behavior of toluene and n-hexane in gamma-alumina membranes with different pore diameters was studied. It was shown that the permeability of water-lean hexane and toluene is in agreement with Darcy's law down to membrane pore diameters of 3.5 nm. The presence of molar water fractions of 5-8 x 10(-4) in these solvents led to a permeability decrease of the gamma-alumina layer by a factor of 2-4 depending on pore size. In general, a lower permeability was found for hexane than for toluene. Moreover, in the presence of water a minimum applied pressure of 0.5-1.5 bar was required to induce net liquid flow through the membrane. These phenomena were interpreted in terms of capillary condensation of water in membrane pores with a size below a certain critical diameter. This is thought to lead to substantial blocking of these pores for transport, so that the effective tortuosity of the membrane for transport of hydrophobic solvents increases.