In this work, uniform and nanosize(75nm) silicalite-1 crystals was hydrothermally synthesized by using 9TPAOH:0.16NaOH:25Si:495H2O solution at 80 ℃. They were applied as seed in the secondary growth process for preparing silicalite-1 membrane by template-free method. The highest ethanol/water separation factor of 119 with flux 0.58kg/m². Furthermore, these membranes (nano seed, template free silicalite-1 membrane) exhibit high permselectivity of He over SF6(123), and small gas permeation mechanism and Knudsen diffusion studies suggest that the membranes contain negligible intercrystalline or non-zeolite pores.

In this work, uniform and nanosize(75nm) silicalite-1 crystals was hydrothermally synthesized by using 9TPAOH:0.16NaOH:25Si:495H2O solution at 80 ℃. They were applied as seed in the secondary growth process for preparing silicalite-1 membrane by template-free method. And silicalite-1 membrane, which was coated by nano-size seed, showed a high EtOH/H2O separation factor of 128. The high separation factor could be explained by the role of nanosize seed. The application of nanosize seed successfully retarded the formation of interfacial voids between silicalite-1 grains. Therefore, it could be concluded that template-free hydrothermal process can produce silicalite-1 membrane with well performance.