pH值对氢氧化铝晶相及微结构的影响

Influence of pH Value on Crystal Structure and Microstructure of Aluminum Hydroxide

采用XRD、ATR-FTIR及TEM等表征手段,系统研究pH值对化学液相沉淀所制备氢氧化铝的晶相和微结构的影响.结果表明,随着溶液pH值从5增加到11,氢氧化铝晶体结构依次为非晶态氢氧化铝、勃姆石[γ-AlOOH]、拜耳石[α-Al(OH)3],相应粉体颗粒由分散的、超细的纳米絮粒到平均直径为50 nm的絮球,再到150 nm无规则的团聚体.这表明,采用液相沉淀法制备氢氧化铝时,溶液的pH值明显影响氢氧化铝的晶相、颗粒形貌、粒径大小及团聚程度.

The paper systematically investigates the influence of pH value on the crystalline phase and microstructure of aluminum hydroxide synthesized by the chemical liquid deposition method by XRD,ATR-FTIR,and TEM analytical techniques.The results indicate that with increasing pH value from 5 to 11,the crystal structure of aluminum hydroxides precipitated from the solution varies from amorphous phase through bohmite [γ-AlOOH] to bayerite [α-Al（OH）3];and the corresponding morphology of the aluminum hydroxide particles changes from the ultrafine floccules through blowballs with 50 nm average diameter then to the irregular agglomerates with 150 nm average diameter.That indicates that the pH value of solution remarkably influences the microstructure,morphology,grain diameter,and aggregation of aluminum hydroxide synthesized by the chemical liquid deposition method.