过饱和沉淀法合成Zn-Al类水滑石及其表征

分别用高、低过饱和沉淀法合成了n（Zn）／n（Al）=2：1的Zn—Al类水滑石（HTlc），并用XRD对所获得的水滑石样品进行了表征，结果表明：高过饱和沉淀法合成的水滑石的谱峰比低过饱和沉淀法合成的水滑石的谱峰更尖锐，说明高过饱和沉淀法的结晶效果优于低过饱和沉淀法．基于此，利用高过饱和沉淀法合成了一系列的Zn-Al-HTlc，并通过XRD，IR和TG进行了表征，研究了样品中的n（Al）／n（zn＋Al），即x对Zn-Al-HTlc化学组成、晶体结构的影响．当0．25≤x≤0．51时可得到单一的Zn-Al-Cl-HTlc相；x≤0．25时有ZnO杂质相出现；x值对晶胞参数a和c的影响不大．

Zn-Al Hydrotalcite Produced by Saturated Precipitation Method and Its Structure Characterization

Some Zn-Al hydrotalcites which the molar ratio of Zn to Al is 2：1 were synthesized respectively by high and low saturated precipitation methods, The synthesized Zn-Al-carbonate hydrotalcite samples were characterized by XRD, IR and DSC-TGA. It was found that the high saturated precipitation synthetic hydrotalcite peaks than the low saturated precipitation peaks is more acute. This may show that high saturated precipitation crystallization is better than low saturated precipitation. A series of hydrotalcites were synthesized using high saturated method and were characterized by XRD, IR and TG. The impact of hydrotalcite＇ s chemical composition and crystal structure were studied by changing the molar ratio （x） of Al to （ Zn ＋ Al） in the samples. Results show that pure HTlc phase could be got when 0.25≤x≤0.51 ; when x≤0.25, ZnO would emerge, x value has little impact on the unit cell parameters a and c.