M/PDMS复合膜的制备及其CO_(2)/N2分离性能

Preparation of M/PDMS composite membrane and its CO_(2)/N2 separation performance

通过梯度烧结法制备得到莫来石陶瓷膜,将不同相对分子质量的硅橡胶类聚合物聚二甲基硅氧烷(PDMS)按不同比例进行混合,涂覆在莫来石陶瓷膜表面以覆盖陶瓷膜表面孔径,得到M/PDMS复合膜,PDMS提高了M/PDMS复合膜对CO_(2)的吸附性能和CO_(2)/N_(2)的选择性。通过XRD、SEM对莫来石陶瓷膜和M/PDMS复合膜进行结构性能表征,并采用自制气体分离装置测试膜对单一气体的渗透速率并计算CO_(2)/N_(2)的分离性能。结果表明,在室温条件及0.2 MPa的操作压力下,M/PDMS复合膜对CO_(2)的渗透速率高达2300 GPU;CO_(2)/N_(2)选择性为1.52。

The mullite phase ceramic membrane was prepared by gradient sintering method.The silicone rubber polymer PDMS with different molecular weights were mixed in different proportions,and coated on the surface of ceramic membrane to cover the surface pore diameter of Ceramic membrane to obtain composite membrane M/PDMS.PDMS improved the adsorption capacity of composite membrane for CO_(2)and the selectivity of CO_(2)/N_(2).The physical and chemical properties of the membrane before and after modification were characterized by XRD,SEM and a self-made gas separation device was used to test the permeability rate of the membrane to a single gas and calculate the separation performance of CO_(2)/N_(2).The results showed that under room temperature conditions and operating pressure of 0.2 MPa,the permeability of the composite membrane to CO_(2)was as high as 2300 GPU;The CO_(2)/N_(2)selectivity is 1.52.