The University of Queensland, FIMLab - Films and Inorganic Membrane Laboratory, School of Chemical Engineering, Brisbane, Qld 4072, Australia.
J Colloid Interface Sci. 2012 Feb 15;368(1):70-6. doi: 10.1016/j.jcis.2011.10.041. Epub 2011 Oct 25.
This work shows for the first time the potential of cobalt oxide silica (CoO(x)Si) membranes for desalination of brackish (1 wt.% NaCl), seawater (3.5 wt.% NaCl) and brine (7.5-15 wt.% NaCl) concentrations at feed temperatures between 25 and 75 °C. CoO(x)Si xerogels were synthesised via a sol-gel method including TEOS, cobalt nitrate hydrate and peroxide. Initial hydrothermal exposure (<2 days) of xerogels prepared with various pH (3-6) resulted in densification of the xerogel via condensation reactions within the silica matrix, with the xerogel synthesised at pH 5 the most resistant. Subsequent exposure was not found to significantly alter the pore structure of the xerogels, suggesting they were hydrostable and that the pore sizes remained at molecular sieving dimensions. Membranes were then synthesised using identical sol-gel conditions to the xerogel samples and testing showed that elevated feed temperatures resulted in increased water fluxes, whilst increasing the saline feed concentration resulted in decreased water fluxes. The maximum flux observed was 1.8 kg m(-2) h(-1) at 75 °C for a 1 wt.% NaCl feed concentration. The salt rejection was consistently in excess of 99%, independent of either the testing temperature or salt feed concentration.
这项工作首次展示了氧化钴硅（CoO(x)Si）膜在 25 至 75°C 的进料温度下，对咸水（1wt.%NaCl）、海水（3.5wt.%NaCl）和盐水（7.5-15wt.%NaCl）浓缩物进行脱盐的潜力。CoO(x)Si 干凝胶通过溶胶-凝胶法合成，包括 TEOS、硝酸钴水合物和过氧化物。在不同 pH 值（3-6）下制备的干凝胶进行初始水热暴露（<2 天），导致硅基质内的缩合反应使干凝胶致密化，pH 值为 5 时合成的干凝胶最具抵抗力。随后的暴露并没有发现明显改变干凝胶的孔结构，这表明它们具有水稳定性，并且孔径仍保持在分子筛尺寸。然后使用与干凝胶样品相同的溶胶-凝胶条件合成膜，测试表明升高的进料温度导致水通量增加，而增加盐水进料浓度导致水通量降低。在 75°C 时，观察到的最大通量为 1.8kgm(-2)h(-1)，进料浓度为 1wt.%NaCl。盐的截留率始终超过 99%，与测试温度或盐进料浓度无关。
