3.1. Effect of Multi-Layers Seeds on Membrane Performance
ZSM-5 zeolite layer was synthesized on the surface of seeded tubular
alumina substrates with a seed layer in three different compositions
using the secondary growth method. The number and combination of each
series are shown in Tables 1-3. Table 1 shows the series SLS samples
prepared by a single-layer seeding method using seeds of different
sizes. Table 2 shows the series DLS membranes were grown on the
two-layer seeded supports using zeolite seeds of different sizes. Table
3 shows the series TLS samples were synthesized by the triple-layer
seeding method using three different seed particle sizes. All the
samples were subjected to an isothermal secondary growth at
180oC for 10 h and then characterized for
morphology/phase-structure gas and permeance/selectivity.
Table 1: ZSM-5 tubular zeolite membranes prepared with one-layer seeding
method (SLS)