锌铝类水滑石的复原及表征(英)

本文采用焙烧复原法，在70 ℃以80%的乙醇溶液为分散介质，有机酸阴离子与煅烧后的锌铝类水滑石的物质的量之比为1∶9的条件下，实现了苯甲酸及苯二甲酸异构阴离子与锌铝类水滑石的插层反应，同时，还进行了等物质的量的两种酸与锌铝类水滑石（1∶1∶9）的插层反应。利用XRD和IR测试技术对样品结构进行表征，UV及HPLC对有机酸的反应量进行定量，并采用Gaussian-98软件包中ab initio分子轨道法（HF/6-31G）计算了各有机酸阴离子的分子结构，分析了其结构与插层行为的关系，并理论结合实验给出了各有机酸阴离子在锌铝类水滑石层间可能的空间构型。研究结果表明，苯甲酸及苯二甲酸异构阴离子在插层过程中表现出选择性，其优先进入锌铝类水滑石层间的顺序是：对苯二甲酸>邻苯二甲酸>间苯二甲酸>苯甲酸，且锌铝类水滑石对对苯二甲酸表现出较高的选择性，是环境友好的分离方法。

Reconstruction and Characterization of Zn,Al Hydrotalcite Like Compound

Intercalation of 1,2-,1,3-,1,4-benzenedicarboxylate or benzenecarboxylate ions into Zn,Al-HTlc was carried out by the reconstruction method in the molar ratio of organic acid: calcined HTlc=1:9, in 80 % alcoholic aqueous solution at 70 ℃. Selective reaction was observed in competitive experiments involving an equal concentration pairs of acids. The structures of the intercalates formed by reaction of four guests with Zn, Al-HTlc were characterized by XRD and IR techniques. And the charge density on the oxygens of each of the carboxylate groups for each of the four anions was investigated utilizing ab initio (HF/6-31G) method by G98w. The orientation of 1,2-,1,3-,1,4-benzenedicarboxylate or benzenecarboxylate anions between the layers was also proposed.The results show that the preference order for intercalation of all guests in Zn,Al-HTIc was 1,4-benzenedicarboxylate ＞ 1,2-benzenedicarboxylate ＞ 1,3-benzenedicarboxylate ＞ benzenecarboxylate. This material exhibits the preferential intercalativity for 1,4-benzenedicarboxylate from mixed pairs of organic acids and will be exploited as a method for the chemical separation of these anions from solution.