Modification of carbon membranes and preparation of carbon-zeolite composite membranes with zeolite growth

A novel method for the modification of carbon membranes was developed by zeolite growth on the surface of porous carbon tubes using a hydrothermal synthesis method and carbon-zeolite composite membranes were successfully obtained. Zeolite seeds for the zeolite growth were introduced to the inner surface of the tubes by using a slip-casting technique in 1 wt.% seed ethanol solution and continuous and highly intergrown zeolite layers on the seeded tubes were formed by subsequent hydrothermal synthesis. Different types of zeolite layers can be grown on porous carbon tubes by using different types of zeolite seeds. Without zeolite seeds, a zeolite layer could not be formed on the carbon surface. SEM, XRD and pure gas permeation characterization indicates that the carbon-zeolite membranes are continuous and defect-free.