Facile Preparation of Bilayer Titanium Silicate (TS-1) Zeolite Membranes by Periodical Secondary Growth

Abstract

A facile periodical secondary growth method, based on conventional secondary growth, is proposed to prepare bilayer TS-1 membranes. The novel periodical secondary growth consists of two or several periods, which involve three steps: the temperature is programmed to a desired crystallization temperature as the first stage, followed by holding for a certain duration, and finally cooling to room temperature. This periodical crystallization model enables a bilayer TS-1 membrane to be produced, while the conventional secondary growth method produces a monolayer TS-1 membrane. The bilayer TS-1 membrane exhibits a superior defect-free structure and hydrophobic properties, as illustrated by SEM, gas permeance, pore size distribution analysis, and water contact angle measurement. It displays an earlier desalination separation factor compared to the monolayer TS-1 membrane. This work demonstrates that the periodical secondary growth is an advanced approach for preparing a bilayer zeolite membrane with excellent properties.

Solution-combustion Synthesized Nano-pellet α-Al2O3 and Catalytic Oxidation of Cyclohexane by Its Supported Cobalt Acetate

“…It is the highest crystallization and most stable phase of all crystalline alumina. α-Al 2 O 3 possesses a variety of superior properties, like excellent mechanical properties, strong corrosion resistance, high temperature resistance, prominent insulation, etc., widely applied in wear resistance of polymer materials, ceramic materials, refractory materials, abrasives, ceramic substrates, and optical materials [9][10][11][12][13][14][15] . It has been recently found that a-Al 2 O 3 assumes unique advantages as the catalyst carrier due to its inertness at high temperatures, especially, catalytic properties of the support phase being not impeded [16][17][18][19][20] .…”