Effect of the phase-separated structure on CO2 separation performance of the poly(amidoamine) dendrimer immobilized in a poly(ethylene glycol) network
Effect of the phase-separated structure on CO2 separation performance of the poly(amidoamine) dendrimer immobilized in a poly(ethylene glycol) network
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DOI：
10.1039/c3ta13711b
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发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Jinnai, Hiroshi
中科院分区：
文献类型：
--
作者：
Taniguchi, Ikuo;Duan, Shuhong;Jinnai, Hiroshi
聚（酰胺基胺）（PAMAM）树状聚合物在PEG二甲基丙烯酸酯（PEGDMA）的存在下光交联后稳定地固定在聚（乙二醇）（PEG）网络中。通过激光扫描共聚焦显微镜（LSCM）对所得聚合物共混物的结构分析揭示了在微米尺度上聚合诱导的相分离和富PEG和富PAMAM树枝状聚合物相的双连续结构的形成。当树枝状聚合物含量为50wt%时，取决于PEG长度，确定与富PEG相的平均间距相同的平均树枝状聚合物结构域尺寸为2.2 - 2.8 μ m。当使用聚合物共混物制造膜时，所得膜显示出优异的CO2分离性能，尤其是在较高湿度条件下。在潮湿条件下的CO2分离性能与干燥状态下的树枝状聚合物结构域尺寸有关。较小的树枝状聚合物结构域尺寸在潮湿条件下提供较高的CO2渗透性和CO2/H-2选择性。吸收的水诱导树枝状聚合物扩散到富PEG相中，这引起CO2在聚合物共混物中的溶解度的增强。因此，扩散的树枝状聚合物将更有利于CO2的渗透，提供更高的CO2/H-2选择性。
The poly(amidoamine) (PAMAM) dendrimer is stably immobilized in a poly(ethylene glycol) (PEG) network upon photo-crosslinking of PEG dimethacrylate (PEGDMA) in the presence of the dendrimer. Structural analysis of the resulting polymeric blend by laser scanning confocal microscopy (LSCM) reveals polymerization-induced phase separation on a micron scale and the formation of a bicontinuous structure of PEG-rich and PAMAM dendrimer-rich phases. The average dendrimer domain size, which is identical to the average spacing of the PEG-rich phase, is determined to be 2.2-2.8 mu m depending on the PEG length when the dendrimer content is 50 wt%. When a membrane is fabricated using the polymeric blend, the resulting membrane shows excellent CO2 separation properties over H-2 especially under higher humidified conditions. The CO2 separation properties under humidified conditions are associated with the dendrimer domain size in the dry state. A smaller dendrimer domain size gives higher CO2 permeance and CO2/H-2 selectivity under humidified conditions. Absorbed water induces diffusion of the dendrimer into the PEG-rich phase, which gives rise to the enhancement of the solubility of CO2 in the polymeric blend. As a result, the permeation of CO2 will be more facilitated by the diffused dendrimer, providing a higher CO2/H-2 selectivity.