Evaluating the gas permeation properties and hydrothermal stability of organosilica membranes under different hydrosilylation conditions
Evaluating the gas permeation properties and hydrothermal stability of organosilica membranes under different hydrosilylation conditions
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不同硅氢加成条件下有机硅膜的气体渗透性能和水热稳定性评价
DOI：
10.1016/j.memsci.2015.06.059
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发表时间：
2015
影响因子：
9.5
通讯作者：
T. Tsuru
中科院分区：
文献类型：
--
作者：
M. Kanezashi;H. Sazaki;H. Nagasawa;T. Yoshioka;T. Tsuru
通过控制三乙氧基硅烷(TRIES)与乙烯基三甲氧基硅烷(VTMS)的摩尔比、硅氢化反应温度等溶胶制备条件，制备了有机硅膜。考察了有机硅膜的单气体渗透性能和水热稳定性，以阐明水热稳定性与有机硅结构的关系。采用铂催化热固化硅氢加成反应考察了硅氢加成反应温度对膜性能的影响。有机硅膜(40℃下铂催化硅氢化反应)在500℃时表现出约10−6mol/m−2s−1PaCF1的H_2选择性(H_2/CH_4：15，H_2/−_4：950)，在500℃氧化气氛中稳定。通过热固化(500℃，N_2)得到的硅氢化反应活性强烈依赖于SQ溶胶中TRIES/VTMS(=H/V)的比值，且ANH/V比值为1.25时表现出较高的硅氢化反应活性。其水热稳定性优于无定形SiO_2膜，这是由于Si-(CH_2)_2-Si单元通过硅氢化作用进入网络，降低了He/H_2渗透率、He/H_2渗透率和水蒸气处理前后的活化能。
Organosilica membranes were fabricated under controlled sol-preparation conditions such as the ratio of triethoxysilane (TRIES) and vinyltrimethoxysilane (VTMS) and the hydrosilylation temperature. The single-gas permeation properties and hydrothermal stability of organosilica membranes were evaluated to clarify the relationship between hydrothermal stability and organosilica structure. Pt-catalyzed and thermally cured hydrosilylation was applied to evaluate the effect that hydrosilylation temperature exerts on the properties of membranes. Organosilica membranes (Pt-catalyzed hydrosilylation at 40 °C) showed H2permeance of approximately 10−6mol m−2s−1Pa−1with H2selectivity (H2/CH4:15, H2/CF4:950) at 500 °C, and were stable under an oxidative atmosphere at 500 °C. The organosilica network size derived by thermal curing at 500 °C was smaller than that by Pt-catalyzed hydrosilylation, even though the units (Si–C–C–Si, Si–O–Si) were the same. Hydrosilylation reactivity derived by thermal curing (500 °C, N2) strongly depended on the TRIES/VTMS (=H/V) ratio in the SQ sol, and anH/Vratio of 1.25 showed a higher level of hydrosilylation reactivity. Its hydrothermal stability was better than that of amorphous silica membranes, due to the incorporation of Si–(CH2)2–Si units in the networks via hydrosilylation, based on the decreased ratio of He and H2permeance, the He/H2permeance ratio, and the activation energy before/after steam treatment.