Preparation of Inorganic Compounds at Near Room Temperature by the Direct Conversion of Borate Glass in Solutions of the Corresponding Anions
作者:Wenhai Huang、Mohamed N. Rahaman、Delbert E. Day、Xin Liu
DOI:10.1111/j.1551-2916.2008.02425.x
日期:2008.7
The preparation of alkaline‐earth chromate, selenite, and stannate compounds at near room temperature by the direct conversion of borate glass in aqueous solutions of the corresponding anions was investigated. Borate glass particles (150–300 μm) with the composition 20Na2O·20CaO·60B2O3 or 20Na2O·20BaO·60B2O3 (mol%) were prepared by conventional methods and immersed in dilute solutions of K2CrO4, K2SeO3, or K2SnO3 at 37°C. The conversion of the glasses was monitored using weight loss and pH measurements, while X‐ray diffraction (XRD), X‐ray fluorescence, and scanning electron microscopy were used to characterize the structure and composition of the products. After a reaction for 140–320 h, porous crystalline products identified by XRD as CaSeO3.H2O, CaSnO3.3H2O, BaCrO4, and BaSeO3 were obtained. The conversion of fibers (0.5–1.0 mm in diameter) of the Na2O–BaO–B2O3 glass in K2CrO4 solution was pseudomorphic. The kinetics and mechanisms of the conversion process, as well as the structure of the products, are discussed.
通过将硼酸盐玻璃直接转化为对应的阴离子在水溶液中的化合物,研究了在近室温条件下制备碱土铬酸盐、亚硒酸盐和锡酸盐化合物的方法。采用常规方法制备了组成分别为20Na₂O·20CaO·60B₂O₃或20Na₂O·20BaO·60B₂O₃(mol%)的硼酸盐玻璃颗粒(粒径150–300 μm),并将其浸入37°C的稀K₂CrO₄、K₂SeO₃或K₂SnO₃溶液中。通过重量损失和pH测量监测玻璃的转化过程,同时使用X射线衍射(XRD)、X射线荧光和扫描电子显微镜来表征产物的结构和组成。经过140–320小时的反应,获得了XRD鉴定为CaSeO₃·H₂O、CaSnO₃·3H₂O、BaCrO₄和BaSeO₃的多孔晶体产物。Na₂O–BaO–B₂O₃玻璃纤维(直径0.5–1.0 mm)在K₂CrO₄溶液中的转化呈现出拟态转变。讨论了转化过程的 kinetics、机理以及产物的结构。