高白填料氢氧化铝的微观结构

Study on Microstructure of High Whiteness-Aluminum Hydroxide Fillers

不同分解工艺生产的高白填料,其氢氧化铝晶体生长形态不同.采用扫描电镜、X射线衍射和拉曼光谱等分析手段研究了碳分和种分氢氧化铝高白填料产品的微观结构,揭示了它们晶体发育的变化.结果表明,高白填料氢氧化铝晶体属单斜晶系,空间群P21/n,择优生长晶面均为(002)晶面;种分氢氧化铝晶体比碳分氢氧化铝晶体的(002)晶面择优取向因子值小,为多晶面生长;种分氢氧化铝晶体晶格参数比碳分氢氧化铝晶体晶格参数和拉曼光谱特征峰半高宽数值小,因此,种分高白填料氢氧化铝晶体中杂质和晶格缺陷比较少,晶体结晶度明显好于碳分高白填料产品.

High-whiteness aluminum hydroxide fillers obtained from different precipitation techniques are all possessed of their own morphology of crystal growth. The microstructures of the fillers obtained from both carbonization precipitation and seed precipitation were investigated by scanning electron microscope （SEM）, X-ray diffraction and Raman spectra. The results showed that the aluminum hydroxide crystals of high-whiteness fillers belong to monoclinic system with the space group P21/n, and the preferred growth crystal faces in both precipitations are （002）, while the value of preferred orientation factor of seed precipitation crystals is smaller than that of carbonization precipitation crystals, and the former is of polycrystal face growth. Comparing the seed precipitation crystals with carbonization precipitation ones, the former＇ s lattice parameter and Raman full width at half-maximum （FWHM） are both lower than the lattter＇ s, as well as the crystalline inclusions and lattice defects. However, the former＇ s crystallinity is remarkably superior to the lattter＇ s.