α'-AlH_3的制备及形成研究

Preparation of α'-AlH_3 and its crystallization process

以LiAlH_4和AICI_3为原料,通过乙醚法制备了AlH_3,采用扫描电子显微镜(SEM)和X射线粉末颜射(XRD),研究了制备条件对产物形貌、晶型的影响规律。结果表明,氢化铝醚合物高温脱醚时,混合溶剂中乙醚比例是影响AlH_3晶型及形貌的主要因素,当结晶时,体系中乙醚不能及时除去,会导致α'-AlH_3的形成,且AlH_3形貌逐渐由立方体变成绒球状。伴生的α'型对AlH_3室温存储稳定性及安全性有较大影响,α'型存在加快AlH_3在室温下分解,且使得样品摩擦感度升高。

AlH3 was prepared in ether using LiAlH4 and AICI3 as the starting materials.The crystallization of non-solvated AlH3 from the solvent was studied by X-ray diffraction （XRD） and Scanning electron microscopy （SEM）.Ether plays an important role in the crystallization and formation of α＇-AlH3 in terms of morphology and phase fraction.If ether were not removed from the crystallization system on time,it became an impurity,leading to formation of α＇-AlH3.Furthermore,the effects of α＇-AlH3 on the thermal stability and sensitivity of AlH3 were studied.The presence of α＇-AlH3 could increase the decomposition rate and friction sensitivity of AlH3.