Effects of curing temperature and water glass modulus on the preparation of hierarchical zeolite precursors

Abstract

The hierarchical design of zeolite materials from alkali-activated solid waste is a controversial topic. Deactivated ZSM-5 can serve as a potential foaming material for the preparation of porous zeolite precursors. This article evaluated the suitability of deactivated ZSM-5 for the preparation of porous zeolite material precursors. Curing temperature and water glass modulus were selected to regulate the properties of alkali-activated cementitious material. Two different moduli of water glass (1.4 M and 2.0 M) were applied to determine the effect of samples cured at three temperatures (25 ℃, 50 ℃ and 75 ℃). Characterization analyses such as XRD, FTIR, TG/DTA, SEM/EDS and MIP were performed to analyse the final products and pore structure of the precursors. A higher curing temperature and alkalinity have a substantial influence on the mechanical properties and yield a higher degree of polymerization of the reaction products. The main reaction product in the precursors was the N-A-S-H gel, whose degree of polymerization is strongly influenced by the Si/Al ratio. The purpose of this article is to design porous structures for zeolite precursors. The research results provide promising guidance for the preparation of zeolites with more active sites, high strength and porous structures that are self-supported.