镍铝水滑石的合成及其剥离表征

Synthesis of NiAl hydrotalcite and its characteristics after stripping

通过控制变量如镍铝摩尔比、镍铝与尿素的摩尔比、反应时间、反应温度,利用尿素法合成了一系列镍铝水滑石,旨在找到适合于剥片的水滑石;并且研究了剥离后水滑石的形态和光学特性。借助XRD和SEM分析发现,在n(Ni)∶n(Al)∶n(尿素)=3∶1∶9、反应温度为180℃、反应时间为24 h时,能得到规整度最好、粒径最大的水滑石样品。同时对在该反应条件下得到的样品进行振荡剥离,用AFM表征其剥离厚度为1.5~4.0 nm、粒径约为20 nm;同时,利用UV-Vis测定剥离胶体样品的光学特性,发现胶体质量浓度与吸光度之间符合线性规律。

By controlling variables such as molar ratio of Ni to Al,molar ratio of(Ni+Al)to urea,reaction time,reaction temperature,some NiAl hydrotalcites were synthesized by use of urea process and tried to produce hydrotalcite amenable for stripping.The morphological and optical properties of hydrotalcite after stripping were studied.With the help of XRD and SEM analyzers,it was found that the hydrotalcite sample with the best regularity and the largest particle size could be obtained at molar ratio of Ni to Al to urea(3∶1∶9),the reaction temperature of 180℃and the reaction time of 24 h.At the same time,the sample was subjected to oscillatory stripping under the said reaction conditions,when being characterized by AFM,its stripping thickness was 1.5-4.0 nm and particle size was 20 nm.Meanwhile it was also found that colloid content in the stripped sample was linearly related to absorbance.