Preparation and characterization of high water perm-selectivity ZSM-5 membrane without organic template

Abstract

Abstract Well water perm-selectivity ZSM-5 membranes were rapidly prepared from an aluminum-rich and organic template-free precursor gel by the static secondary hydrothermal synthesis. Influences of synthesis parameters (i. e., crystallization time, support type, silica source, fluoride source, fluoride and alkalinity) on the growth and morphology of ZSM-5 membranes were investigated based on the results of XRD, SEM, TEM characterization and pervaporation (PV). The colloidal silica and nanometer silicalite-1 crystals were found to accelerate the preparation of the well-intergrowth and aluminum-rich ZSM-5 membrane. Without organic template, appropriate ratios of NaF/SiO 2 and Na 2 O/SiO 2 in the precursor gel were crucial to prepare a continuous and compact ZSM-5 membrane. Besides, the perm-selectivity of as-synthesized membranes was significantly dependent on the nature of supports. Under the optimum synthesis conditions, the ZSM-5 membrane Z9 was prepared and applied to dehydration of different H 2 O/organic mixtures by PV. For dehydration of 50 wt% H 2 O/IPA mixture at 75 °C, the total flux and separation factor of Z9 membrane were achieved to 6.25 kg m −2 h −1 and 1000, respectively. Furthermore, Z9 also exhibited a great hydrophilic property for dehydration of other organic aqueous, and the dehydration perm-selectivity performance was as follows: H 2 O/Acetone>H 2 O/IPA>H 2 O/EtOH>H 2 O/MeOH.