有机胺在离子热合成LTA型磷酸铝分子筛中的助模板作用

The Cooperative Templating Effect of Organic Amine in the Ionothermal Synthesis of LTA Type Aluminophosphate Molecular Sieves

在1-丁基-3-甲基溴化咪唑([bmim]Br)离子液体中引入有机胺合成了LTA型磷酸铝分子筛(AlPO4-42),采用热重分析、核磁共振光谱、红外光谱以及荧光光谱对所得晶化产物进行了表征,并考察了体系的晶化动力学.结果表明,有机胺以特定的聚集形态协同离子液体阳离子起到助模板剂的作用,并填充在AlPO4-42分子筛孔道中.晶化产物随晶化时间的演变表明,体系中有机胺浓度的变化改变了动力学路径.高浓度有机胺所形成的聚集体组装周围的无机物种,促进了sod或lta笼结构的形成,并导致立方相的LTA骨架晶化.

The LTA type aluminophosphate molecular sieve （AlPO4-42） was ionothermally synthesized by introducing organic amine into the 1-butyl-3-methylimidazolium bromide （[bmim]Br） ionic liquid.The as-synthesized products were characterized and the crystallization kinetics was investigated.Thermal gravimetric analysis,nuclear magnetic resonance spectroscopy,and infrared spectroscopy demonstrated that the organic amine and the cation of the ionic liquid filled in the channels of the molecular sieve together.The introduced amine acted as the synergetic templates in a certain aggregated state according to the result of photoluminescence emission spectroscopy.The final products varied with the crystallization time,and the kinetic pathway was influenced by the amine concentration,which decreased with the growth of the crystal product during the crystallization.The inorganic materials reassembled around these aggregated templates when they exist in a high concentration to form sod or lta cages,resulting in the crystallization of cubic LTA framework.