PVP对Ca-Al水滑石形貌的控制

Morphology control of Ca-Al layered double hydroxides using polyvinylpyrrolidone as template

用常规方法制备的层状双金属氢氧化物(简称LDHs)为片状结构。采用聚乙烯吡咯烷酮(PVP)为模板制备了弯曲片状的CaAl-LDHs。试验结果表明,在a轴方向CaAl-LDHs晶粒的生长受到了抑制,晶粒尺寸从68.34nm减小到34.17nm,c轴方向CaAl-LDHs晶粒的生长几乎没变化,保持在60.76nm左右。使CaAl-LDHs在a轴方向的晶粒生长速率小于c轴方向的晶粒生长速率。这些可能与溶液中PVP特定的立体化学构象以及和CaAl-LDHs的特殊协同作用有关。

Layered double hydroxides （LDHs） synthesized by conventional methods are usually hexagonal platelet morphology. In this paper,using polyvinylpyrrolidone as template for synthesis of CaA1-LDHs. The CaA1- LDHs particles are curved in the a direction deviating from the flat platelets. The erystallite growth in a directions is inhibited and crystallite size is decreases from 68.34 to 34.17nm. In the c direction, the crystallite size is keep in 60.76nm. This is indicate the crystallite growth speed of a directions is less than the c directions. All of this may be contribute the stereochemical structure of PVP in the aqueous solution and the cooperative organization with CaA1-LDHs.