A形体过量β沸石的晶化过程

Crystallization Process of Polymorph A Enriched β-Zeolite

以四乙基氢氧化铵(TEAOH)为结构导向剂,在超浓水热条件下合成了手性多形体A(简称A形体)过量的β沸石,对初始凝胶的性质及晶化过程进行了深入研究,测定了相应的晶化曲线.研究结果表明,与晶化出A形体含量低于50%的普通β沸石的合成体系相比,晶化出A形体过量的β沸石的合成体系中含水量极低,凝胶中过量的水必须在晶化之前通过加热去除,但过度去除初始凝胶中的水则会显著延长晶化时间.在晶化初期,产物中己出现A形体过量特征,随着晶化的进行,A形体的过量程度无显著变化.

In the presence of tetraethylammonium hydroxide,the chiral polymorph A enriched β-zeolite was synthesized.The crystallization process of polymorph A enriched β-zeolite and the key factors that lead to the enrichment of polymorph A during crystallization were investigated.The results show that the enrichment of chiral polymorph A occurred in the early stage of crystallization and the degree of the enrichment of polymorph A did not change during the crystallization.