Synthesis of Monodisperse Zeolite A/Chitosan Hybrid Microspheres and Binderless Zeolite A Microspheres

Abstract

Zeolite A/chitosan hybrid microspheres with uniform particle size of ∼700 μm and high crushing strength were prepared by bioorganic molecule-assisted impregnation-gelation-hydrothermal synthesis of silica/chitosan hybrid microspheres in a sodium aluminate alkaline solution. Binderless zeolite A microspheres with similar particle size and medium crashing strength were subsequently obtained after calcination of the zeolite A/chitosan hybrid microspheres. The silica/chitosan hybrid microspheres were prepared by solidification of chitosan microdroplets, which were formed in a microfluidic device from a silica sol–chitosan aqueous solution, in the sodium aluminate alkaline solution. X-ray diffraction, FT-IR, scanning and transmission electron microscopy, thermogravimetric analysis, and adsorption were applied to examine the obtained products. The zeolite A/chitosan hybrid microspheres are composed of zeolite A crystals with particle sizes of 200–400 nm and chitosan, with zeolite A crystals covered with and lin...