A SiOC membrane with high oxidative stability for gas separation was tailored by utilizing vinyltrimethoxysilane, triethoxysilane, and 1,1,3,3-tetramethyldisiloxane as Si precursors. Amorphous SiOC networks were formed via the condensation of Si–OH groups, the hydrosilylation of Si–H and Si–CH═CH₂ groups, and a crosslinking reaction of Si–CH₃ groups, respectively. The crosslinking of Si–CH₃ groups at temperatures ranging from 600 to 700 °C under a N₂ atmosphere was quite effective in constructing a Si–CH₂–Si unit without the formation of mesopores, which was confirmed by the results of N₂ adsorption and by the gas permeation properties. The network pore size of the SiOC membrane calcined at 700 °C under N₂ showed high oxidative stability at 500 °C and was appropriate for the separation of large molecules (H₂/CF₄ selectivity: 640, H₂/SF₆: 2900, N₂/CF₄: 98). A SiOC membrane calcined at 800 °C showed H₂/N₂ selectivity of 62, which was approximately 10 times higher than that calcined at 700 °C because the SiOC networks were densified by the cleavage and redistribution reactions of Si–C and Si–O groups.

中文翻译：

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量身定制用于分离大分子的热稳定非晶SiOC结构：煅烧温度对SiOC结构和气体渗透性能的影响

通过使用乙烯基三甲氧基硅烷，三乙氧基硅烷和1,1,3,3-四甲基二硅氧烷作为Si前体，定制出具有高氧化稳定性的气体分离SiOC膜。分别通过Si–OH基团的缩合，Si–H和Si–CH═CH ₂基团的氢化硅烷化以及Si–CH ₃基团的交联反应形成非晶SiOC网络。N ₂气氛下，在600至700°C的温度范围内，Si-CH ₃基团的交联非常有效地构建了Si-CH ₂ -Si单元，而没有形成中孔，这一点已由N ₂的结果证实吸附和受气体渗透的特性。N ₂下在700°C下煅烧的SiOC膜的网络孔径在500°C下显示出高氧化稳定性，适合分离大分子（H ₂ / CF ₄选择性：640，H ₂ / SF ₆：2900 ，N ₂ / CF ₄：98）。在800°C煅烧的SiOC膜显示H ₂ / N ₂选择性为62，比在7​​00°C煅烧的SiOC膜高约10倍，因为SiOC网络通过Si–C和Si–2的裂解和再分布反应而致密化O组。