Cu_3(BTC)_2的改性及其填充PDMS/PEI膜的分离性能

Modification of Cu_3( BTC)_2( BTC = benzene-1,3,5-tricarboxylate)and its pervaportion performance as filler in polydimethylsiloxane /polyetherimide( PDMS / PEI) membranes

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%。

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 unmodified Cu3( BTC)2. The composite membranes containing modified Cu3( BTC)2exhibit 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)2was 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)2had 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.