Inorganic Hollow Fiber Loading Of Ordered Mesoporous Silica Film Preparation And Characterization

Ordered mesoporous silica membranes supported by a-alumina hollow fibers were prepared through self-assembling using triblock copolymer PEO₂₀PPO₇₀PEO₂₀(P123) and the blends of P123 and nonionic surfactant C₁₂H₂₅EO₂₃(Brij35) as the structure-directing agents(SDA),respectively.The synthesis condition and tail method of microstructure are researched.And their structures,appearance and pore size distribution were characterized by FTIR,TG-DTA,small X-ray diffraction(SXRD), high-resolution transmission electron microscopy(HRTEM),nitrogen adsorption isotherm, Scanning electron microscopy(SEM) and Gas permeability test.The results of SXRD,HRTEM,and nitrogen adsorption show that the films have a highly ordered two-dimensional hexagonal mesostructure,by using either single or blend nonionic surfactant as the SDA.By varing weight fraction of Brij35 in blend template ,the pore diameter and pore size distribution can be tailed.The BET surface area ,total pore volume and under 6nm poredia percent of an unsupported membrane is 548.84 m²/g, 0.5695 cm³/g and 90.44%,respectively,by using single template.By adding Brij35 as co-template, the pore diameter can be decreased and a more narrow pore size distribution can be obtained.For example,while P123/Brij35(mass ratio)=5:l,the BET surface area ,total pore volume and under 6 run poredia percent is 487.17 m²/g ,0.4303 cm³/g and 95.34%,respectively.SEM images indicate that the membranes supported by porous materials are defect-free.Gas permeability test suggests that the membrane possess gas selectivity.At 0.1 MPa,gas permeability of N₂ is 1.57×10^-5mol/m²·s·Pa, and the separation factors for H₂/N₂ is 2.94 while P123/Brij35(mass ratio)=5:1 ,compared with 1.07×10^-5mol/m²·s·Pa and 2.80,respectively, by using single surfactant P123.It is shown that the gas diffusion through the membrane is governed by Knudsen diffusion mechanism.