反应时间对改进的离子交换法制备谷氨酸_镁铝层状双氢氧化物的影响.docVIP

 反应时间对改进的离子交换法制备谷氨酸/ 镁铝层状双氢氧化物的影响# 李淑萍，齐凤林* 5 10 （江苏省生物功能材料重点实验室，南京师范大学化学与材料科学学院，南京，210097） 摘要：采用改进的离子交换法合成了谷氨酸(Glu)/镁铝层状双氢氧化物(MgAl-LDHs)的纳米 复合物，研究了反应时间对 Glu/LDH 纳米复合物性质和形貌的影响。研究表明，与传统的 离子交换法相比，用改进的离子交换法合成的纳米粒子呈球形片状，且粒径较小；研究还表 明，在保持弱酸性条件下，随着反应时间的增加，复合物的结晶度先增强后减弱，粒子的分 散性先变好后变差，从而得到制备 Glu/LDH 纳米复合物的最佳反应时间为 2 小时，并对可 能的反应机理进行了探讨。 关键词：层状双氢氧化物；谷氨酸；纳米复合物 中图分类号：O614.22 15 Influence of reaction time on the properties of Glutamic Acid / Magnesium Aluminum Layered Double Hydroxides by Improved Ion-Exchange Method LI Shuping, QI Fenglin 20 25 30 (Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, P.R. China) Abstract: The glutamic acid (Glu)/magnesium aluminum layered double hydroxide compounds (MgAl-LDHs) were prepared by the improved ion-exchange method, and compounds (MgAl-LDHs) were prepared by the improved ion-exchangemethod, and compounds (MgAl-LDHs) were prepared by the improved ion-exchange method, and the influence of reaction time on the property and morphology of Glu/LDH compounds were systematically investigated. It was found that compared with the traditional ion-exchange method, the morphology of particles prepared by the improved ion-exchange was spherical shape with smaller size. Furthermore, under the weak acidic conditions, with increasing the reaction time, the crystallinity degree of the compounds first increased then decreased, and the dispersion of particles first became better then worse. Therefore, the optimal reaction time to prepare Glu/LDH compounds by the improved ion-exchange method was 2 hours, and the possible reaction mechanism was discussed. Key words: layered double hydroxide; glutamic acid; nanocompounds 35 40  0 引言 层状双氢氧化物（Layered Double Hydroxide，简称 LDH），是由两种不同 价数的金属离子形成的一种层状双氢氧化物，化学组成式为[1]：[M (Ⅱ)1 - x M (Ⅲ)x (OH)2 ] x + An –x/n ·mH2O，其中，M() 是二价金属离子,M( ) 是三价金属离子, A 是价数为-n 的阴离子；LDH 层间阴离子具有可交换性[2]，可与多种阴离子进 行交换，因而可得到不同结构和功能的柱撑类 LDH 材料。更重要的是，LDH