Abstract Membrane crystallization (MCr) is emerging as an interesting candidate to extract additional freshwater and raw materials from high-concentrated solutions. Traditionally, MCr has been carried out by using polymeric membranes that have limited chemical and mechanical stability. These shortcomings can be overcome by using ceramic membranes. The current study describes the preparation and testing of two hydrophobic ceramic membranes synthesized trough sol-gel process, and combined phase-inversion and sintering method. The first membrane (CM-L) was synthesized by coating hydrophobic polymethylsilsesquioxane aerogels on alumina membrane supports via a sol-gel process. The membrane showed stable hydrophobic character in membrane distillation and crystallization tests but very low flux. To obtain high flux, a second type (CM-S) membrane was prepared by applying Fluoroalkylsilanes (FAS) (1H, 1H, 2H, 2H‑perfluorooctyltriethoxysilane) hydrophobic agent at the relatively thin and more porous as-sintered alumina hollow fibers. The suitability of both membranes for MCr process was analyzed by crystallizing NaCl and LiCl. By using 1 M NaCl and 13 M LiCl aqueous solutions, and under the same operative conditions, CM-S membrane exhibited average flux higher than CM-L membrane. The performance of both the membranes, in terms of hydrophobic character, remained stable throughout the performed tests.

中文翻译：

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陶瓷膜在真空膜蒸馏和真空膜结晶中的性能

摘要 膜结晶 (MCr) 正在成为从高浓度溶液中提取额外淡水和原材料的有趣候选方法。传统上，MCr 是通过使用具有有限化学和机械稳定性的聚合物膜进行的。这些缺点可以通过使用陶瓷膜来克服。目前的研究描述了两种通过溶胶-凝胶工艺合成的疏水陶瓷膜的制备和测试，以及相转化和烧结相结合的方法。第一个膜 (CM-L) 是通过溶胶-凝胶工艺将疏水性聚甲基倍半硅氧烷气凝胶涂覆在氧化铝膜载体上合成的。该膜在膜蒸馏和结晶试验中表现出稳定的疏水特性，但通量非常低。为了获得高通量，通过将氟烷基硅烷 (FAS)（1H、1H、2H、2H-全氟辛基三乙氧基硅烷）疏水剂施加到相对较薄且多孔的烧结氧化铝空心纤维上，制备了第二种 (CM-S) 膜。通过结晶 NaCl 和 LiCl 来分析两种膜对 MCr 工艺的适用性。通过使用 1 M NaCl 和 13 M LiCl 水溶液，在相同的操作条件下，CM-S 膜表现出高于 CM-L 膜的平均通量。两种膜的疏水特性在整个测试过程中都保持稳定。通过结晶 NaCl 和 LiCl 来分析两种膜对 MCr 工艺的适用性。通过使用 1 M NaCl 和 13 M LiCl 水溶液，在相同的操作条件下，CM-S 膜表现出高于 CM-L 膜的平均通量。两种膜的疏水特性在整个测试过程中都保持稳定。通过结晶 NaCl 和 LiCl 来分析两种膜对 MCr 工艺的适用性。通过使用 1 M NaCl 和 13 M LiCl 水溶液，在相同的操作条件下，CM-S 膜表现出高于 CM-L 膜的平均通量。两种膜的疏水特性在整个测试过程中都保持稳定。