金属银负载型SiO2杂化膜的制备与性能表征

Preparation and Characterization of Metallic Silver-Doped Silica Hybrid Membranes

采用溶胶-凝胶法,制备银掺杂的SiO2杂化溶胶和SiO2杂化膜,考察银的掺杂对杂化溶胶的性能和对杂化膜物理化学结构及水汽稳定性的影响.结果表明:随着银含量的增加,溶胶的黏度、粒径增大,凝胶时间缩短;银在杂化膜中以纳米金属银的形式存在,金属银的掺杂对杂化材料的化学结构基本无影响,但使杂化膜的平均颗粒粒径、孔径和总孔体积略微增加;在水汽环境中陈化后,载银SiO2杂化膜的H2渗透速率略有下降,而H2/CO2分离因子小幅升高;金属银的掺杂增强了SiO2膜的水汽稳定性,实现了杂化膜中H2渗透速率和H2/CO2分离因子的同时增大.

The silver-doped silica sol and hybrid membrane were prepared by sol-gel method.The influences of Ag dope on the sol properties,the physical and chemical structures and the steam stability of silica hybrid membranes were investigated.The results show that,with the increase of silver content,the viscosity and particle size of hybrid sol increase,and the gelation time decreases.The silver element in the hybrid membranes exists as metallic nano-silver.The loading of metallic silver exerts little influence on the chemical structure of the methyl-modified silica membranes but makes the mean particle size,pore size and total pore volume of the silica membranes larger.After aging in steam circumstances,the H2 permeation rate of the silica hybrid membranes slightly decreases while the H2/CO2 permselectivity increases by a small margin.The doping of Ag improves the steam stability of silica membrane and increases the H2 permeability and H2/CO2 permselectivity in the silica hybrid membranes simultaneously.