有机添加剂对A型分子筛晶化过程及性能的影响

Influence of Organic Additives on the Crystallization Behaviors and Properties of Zeolite A

采用XRD特征峰高加和法测定了5A分子筛样品的相对结晶度,并与正己烷吸附量进行了关联。研究了8种有机添加剂在较小添加量情况下对A型分子筛晶化过程、5A分子筛吸附性能和晶体尺寸的影响。结果表明:晶化过程中样品的相对结晶度与正己烷吸附量线性相关。K12、TWEEN-80和PEG使诱导期缩短,而TEA和SCMC使诱导期延长。K12、CTAB、TEA、TWEEN-80、PEG、OP和HMTA的加入均不同程度地降低了晶体生长速率。K12、CTAB、TEA、TWEEN-80、OP和HMTA有助于增加A型晶体在晶化体系中的稳定性。SCMC的加入使5A分子筛吸附速率增加。TEA、PEG和HMTA的加入使晶体尺寸增加且分布变窄。

The influences of eight organic additives on the crystallization behaviors and the properties of Zeolite A were studied. Results show that the amount of n hexane adsorption is linearly dependent on the relative crystallinity. K12, TWEEN-80 and PEG would shorten the inducing period of crystal growth and TEA and SCMC prolong the inducting stage. K12, CTAB, TEA, TWEEN-80, PEG,OPand HMTA are found to hinder the crystal growth. The stability of the crystals increases when K12, CTAB, TEA, TWEEN-80, OP or HMTA was added. SCMC would increase the rate of adsorption, while TEA,PEG and HMTA would increase the crystal size and decrease the size distribution.