丙三醇/水体系中制备水滑石晶体及其取向生长

Formation of hydrotalcite nanocrystals by oriented growth in the glycerol/water system

在丙三醇/水体系中通过尿素法制备了a轴晶粒尺寸为39nm低纵横比的MgAl水滑石(MG-LDH)。XRD、FT-IR、SEM、BET、粒度分析和零电荷点等手段,考察了丙三醇对产物形貌的影响。结果表明,丙三醇作为结构导向剂在晶体取向生长(晶面生长选择性及晶粒尺寸)中发挥着至关重要的作用。丙三醇/水环境为纳米晶沿a轴方向生长,亦即(110)晶面的生长提供了有利条件,制得粒径分布窄的薄层MG-LDH,对Cd^(2+)吸附力显著提高。

MgAl hydrotalcites with a crystallite size of 38.61 nm in aaxis direction and low aspect ratio were successfully synthesized by urea method in the glycerol/water system.The effect of glycerol on the morphology development of the products were investigated by means of the XRD,FT-IR,SEM,BET,laser particle analysis and point of zero charge.The results showed that glycerol as excellent solvent and structure director played the key role in the crystal oriented growth such as selectivity of crystal growth in different directions and the particle size of the products.The glycerol/water system provided a crystal growth condition that facilitated the crystal growth in the a direction,i.e[110]crystal plane.The adsorbility of the thin MG-LDH with a narrow particle size distribution to Cd^(2+) was increased.