THERMAL-BEHAVIOR OF HYDRATED DODECATUNGSTOSILICIC ACID

被引：14

作者：

BIELANSKI, A ^{[1
]}

POZNICZEK, J ^{[1
]}

HASIK, M ^{[1
]}

机构：

[1] STANISLAW STASZIC UNIV MIN & MET,DEPT MAT SCI & CERAM,PL-30059 KRAKOW,POLAND

来源：

JOURNAL OF THERMAL ANALYSIS | 1995年 / 44卷 / 03期

关键词：

DODECATUNGSTOSILICIC ACID; DTA-TG; FTIR;

D O I：

10.1007/BF02636289

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The thermal behaviour of H4SiW12O40 . 24.8H(2)O (SiW12) was investigated by using DTA, TG and FTIR. Endothermic effects were observed at 40, 98 and 217 degrees C, corresponding to the fusion of SiW12 in its own crystallization water, boiling of the solution and decomposition of the remaining tetrahydrate into anhydrous SiW12, respectively. The mass of the sample remained constant on hearing from about 250 to 400 degrees C. Subsequently, it slowly decreased and reached a constant value at about 500 degrees C. At 526 degrees C a DTA peak appeared. There was an abrupt change in the FTIR spectrum of the sample heated to 550 degrees C. The typical spectrum of the Keggin unit vanished and new bands at 807.5 and 1030 cm(-1) indicated the presence of free WO3 and SiO2, respectively.

引用

页码：717 / 723

页数：7