摘要
以BPDA-ODA型聚酰亚胺为前躯体,沸石为掺杂剂,通过成膜和炭化等过程制备了杂化炭膜.分别采用热失重、X射线衍射、扫描电子显微镜及渗透技术研究了前躯体热稳定性,炭膜微观结构、形貌及气体分离性能.考察了ZSM-5与5A两种沸石含量、炭化温度、渗透温度及渗透压力等因素对炭膜气体分离性能的影响.结果表明:H_2、CO_2、O_2和N_2 4种气体主要以分子筛分机理渗透通过炭膜,实现选择性分离.在650℃炭化温度下得到杂化炭膜随沸石含量提高,气体渗透性与选择性均略降低;5A杂化炭膜的渗透性与选择性都显著高于ZSM—5杂化炭膜;随渗透压力提高,杂化炭膜的气体渗透性与选择性升高.当炭化温度从650℃升高到750℃时,杂化炭膜的渗透性降低.
Hybrid carbon membranes are first prepared using BPDA-ODA type polyimide and zeolites as precursors and additives,respectively.The thermal stability of the precursor was measured by thermogravimetric analysis.The microstructure,morphology and gas separation performance of resultant carbon membranes were characterized by X-ray diffraction,scanning electronic microscopy and gas permeation technique,respectively.The effects of zeolite types(ZSM-5 and 5A),zeolite dosage, carbonization temperature,and permeation-temperature and permeation-pressure were investigated on the gas separation performance of hybrid carbon membranes.The results have shown that the permeation mechanism for the four gases,H_2,CO_2,O_2 and N_2,is molecular sieving through the hybrid carbon membranes.When the hybrid carbon membranes are prepared at the carbonization temperature of 650℃, both of their permeability and selectivity slightly reduce.In comparison,5A is more favorable than ZSM-5 to be used as additives with the aspect to increase separation performance of resultant carbon membranes. With increasing the permeation pressure,both the permeability and selectivity increase.As the carbonization temperature goes up from 650℃to 750℃,the permeability of hybrid carbon membranes reduces.
出处
《膜科学与技术》
CAS
CSCD
北大核心
2013年第3期33-38,共6页
Membrane Science and Technology
基金
国家自然科学基金(20906063)
辽宁省自然科学基金(20102170)
辽宁省高校优秀人才项目(LJQ2012010)
关键词
聚酰亚胺
炭膜
沸石
渗透性
polyimide
carbon membranes
zeolite
permeability
