对甲基苯甲酸抑制剂对铝酸钠溶液种分过程的影响及其在氢氧化铝（001）面的吸附行为

Effect of p-toluic acid as inhibitor on seed precipitation of sodium aluminate solution and adsorptive behavior on （001） surface of Al（OH）3

分别采用粒度分布测试仪、X射线衍射仪及扫描电镜测定和观察添加1.2×10^-2mol／L对甲基苯甲酸后氢氧化铝晶体的粒度分布、晶型及晶体初期形貌；用Materials Studio Dmol^3模块中的GGA-PW91基组计算对甲基苯甲酸与氢氧化铝（001）面结合前后的态密度、总能量、键合能及费米能级。结果表明，添加1．2×10^-2mol／L对甲基苯甲酸后，与空白相比，产品氢氧化铝的粒径基本不变，晶型不变，初期形貌发生了较大的变化；对甲基苯甲酸不易吸附于氢氧化铝（001）面，不是通过吸附在（001）面来抑制分解的。

The particle size distribution（PSD）, crystal structure and initial microvisage were determined and observed separately by the particle size distribution apparatus, X-ray diffractometer and scanning electron microscope. The fore-and-aft density of state, total energy, binding energy and Fermi energy level after the adsorption of p-toluic acid on the surface （001） of Al（OH）^3 were calculated by the GGA-PW91 in Module-Dmol^3 of Materials Studio. The results show that the particle size distribution of Al（OH）3 keeps basically invariable; the crystal structure of Al（OH）3 is unchanged; but the initial microvisage of Al（OH）3 changes greatly after the p-toluic acid is charged. The p-toluic acid can not easily be adsorbed on the （001） surface of Al（OH）3, thus, it does not inhibit Al（OH）3 crystallization through the adsorption on the （001） surface.