Cu3(BTC)2的改性及其填充PDMS/PEI膜的分离性能

采用水热法合成Cu3(BTC)2晶体,应用3种不同硅氧烷分别对Cu3(BTC)2晶体材料进行表面改性并进行XRD、疏水性能和FI-IR表征。将晶体填充到PDMS/PEI复合膜内制得填充膜,以CO2渗透通量和CO2/N2分离因子为指标对其进行评价,最后使用最佳改性材料K-Cu3(BTC)2对填充膜进行填充率影响的考察。研究结果表明,Cu3(BTC)2晶体成功改性且晶型未被破坏;在实验考察范围内,Cu3(BTC)2改性后的填充膜比未改性时渗透通量减少9.62%,分离因子提升21.13%;填充率为20%时,填充膜的渗透通量与分离因子分别比填充率为10%时提升16.57%和9.01%。

Modification ofCu3(BTC)2 (BTC=benzene-1,3,5-tricarboxylate) and its pervaportion performance as filler in polydimethylsiloxane/polyetherimide (PDMS/PEI) membranes

Cu₃(BTC)₂ (BTC = benzene-1,3,5-tricarboxylate) crystals have been synthesized by a hydrothermal synthesis method, and then modified by three different silane coupling agents. The materials were used as a filler in polydimethylsiloxane/polyetherimide (PDMS/PEI) membranes．The results showed that the hydrophobicity of the modified materials was enhanced compared to unmodifiedCu₃(BTC)₂．The composite membranes containing modifiedCu₃(BTC)₂ exhibit better separation performance then those containing the unmodified material, with K-Cu₃(BTC)₂ (modified with γ-aminopropyltriethoxysilane (K-550)) showing the best performance．The CO2 permeation flux of a modified membrane containing K-Cu₃(BTC)₂ was 0.9038 times the permeance of the umodified membrane and the separation factor for CO2/N2 was 1.2113．A composite membrane with 20% K-Cu₃(BTC)₂ had a permeation flux 1.1657 times that of a 10% K-Cu₃(BTC)₂membrane and the separation factor also increased by a factor of 1.0901．