层状双金属氢氧化物晶粒尺寸的控制

On the Factors Influencing the Crystal Structure and Crystalline Size of Layered Double Hydroxides

以Mg(NO3) 2 ·6H2 O、Al(NO3) 3·9H2 O、NaOH和Na2 CO3为原料 ,采用旋转液膜反应器成核后制备层状镁铝双金属氢氧化物 (LDH)。由晶化温度、晶化过程过饱和度、成核过程过饱和度等对LDH晶体结构及晶粒尺寸的影响实验发现 ,适当降低晶化温度和减小晶化过程过饱和度有利于制备小粒径的LDH ;当盐溶液中的 [Mg2 +]在 0 1～ 1 6mol/L范围时 ,LDH的粒径随 [Mg2

Mg-Al layered double hydroxides(LDH) have been synthesized from Mg(NO 3) 2·6H 2O, Al(NO 3) 3·9H 2O, NaOH and Na 2CO 3 in a rotating liquid- film reactor. It is found that the aging temperature, degree of supersaturation in the course of aging and degree of supersaturation in the course of nucleation are the important factors affecting the crystal structures and crystallite sizes of hydrotalcites. Lower aging temperatures and addition of water during the aging process favour the formation of nano-sized hydrotalcites. When the concentration of Mg 2+ is between 0.1～1.6 mol/L the particle size of LDH increases with increase of the Mg 2+ concentration.