Gas transport properties of thermally rearranged (TR) polybenzoxazole - silica hybrid membranes
Gas transport properties of thermally rearranged (TR) polybenzoxazole - silica hybrid membranes
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热重排（TR）聚苯并恶唑-二氧化硅杂化膜的气体传输特性
DOI：
10.1016/j.polymer.2020.123274
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发表时间：
2021
期刊：
影响因子：
4.6
通讯作者：
Suzuki Tomoyuki
中科院分区：
文献类型：
--
作者：
Sugiyama Hironori;Hattori Yoshiyuki;Suzuki Tomoyuki
采用热重排法和溶胶-凝胶法制备了新型热重排聚苯并恶唑(TRPBO)基二氧化硅杂化膜，并对其气体传输性能进行了研究。在不同温度下重排的原生tr-pbos的自由体积分数(FFV)和d-间隔值均高于作为先驱体的聚(邻羟基亚胺)。TR-PBO-SiO_2杂化材料的透气性随SiO_2含量的增加而增加。气体渗透率的增加主要归因于气体扩散系数的增加，这表明聚合物/二氧化硅界面区域形成了自由体积空穴。TRPBO-SiO_2杂化材料具有优异的CO2/CH4选择性，超过了CO2/CH4分离的上界。显著的CO2/CH4选择性是由于以下两方面的协同作用：(1)通过对PbO的热重排，增大了FFv和d-间距；(2)通过与二氧化硅的杂化，在聚合物/二氧化硅界面区域额外形成了具有尺寸选择性的CO2/CH4分离能力的特征自由体积空穴。
Novel thermally rearranged polybenzoxazole (TR-PBO) -based silica hybrid membranes were prepared via thermal rearrangement and sol – gel processes, and their gas transport properties were investigated. The pristine TR-PBOs rearranged at different temperatures showed higher fractional free volume (FFV) andd-spacing values than the poly(ortho-hydroxy imide) as a precursor polymer. Gas permeability of TR-PBO – silica hybrids increased with increasing silica content. The increased gas permeability was mainly attributed to increased gas diffusivity, suggesting the formation of free volume holes at polymer/silica interfacial region. The TR-PBO – silica hybrids possessed an outstanding CO2/CH4selectivity, exceeding the upper bound trade-off line for CO2/CH4separation. The notable CO2/CH4selectivity was achieved by synergistic effects of (1) enlarged FFV andd-spacing by the thermal rearrangement towards PBO and (2) the additional formation of characteristic free volume holes with a size-selective CO2/CH4separation ability at polymer/silica interfacial region by the hybridization with silica.