五水合六硼酸钙的水热合成及其高温相变研究
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摘要
在120℃的条件下,利用硼酸和石灰进行水热反应制备五水合六硼酸钙(CaB_6O_(10)·5H_2O)。五水合六硼酸钙的差热分析结果显示,其脱水分4步,在800℃和900℃附近分别有一个相变放热峰和吸热峰。对五水合六硼酸钙的高温相变行为进行了探讨,化学分析、XRD、TG-DTA和IR分析结果表明:在600℃时,首先发生晶态的五水合六硼酸钙向非晶态的无水六硼酸钙(CaB6O10)转化,至800℃时无定型的无水六硼酸钙转变为晶态的无水六硼酸钙,进一步升温至900℃时无水六硼酸钙分解为晶态的四硼酸钙(CaB4O7)和玻璃态的三氧化二硼。
CaB_6O_(10)·5 H_2O was synthesized by hydrothermal method at 120 ℃ with using boric acid and lime as materials.The thermal analysis of CaB_6O_(10)·5 H_2O showed that CaB_6O_(10)·5 H_2O was dehydrated by 4 steps,one exothermic peak near 800 ℃and one endothermic peak near 900 ℃ were found,respectively.The high temperature phase transition behavior of CaB_6O_(10)·5 H_2O was discussed by chemical analysis,XRD,TG-DTA and IR analysis.The results indicated that:the first crystalline CaB_6O_(10)·5 H_2O was converted to amorphous CaB6 O10 at 600 ℃,and the amorphous CaB_6O_(10) was converted to crystalline CaB6 O10 at 800 ℃,and finally CaB4 O7 and vitreous B2 O3 were obtained by the decomposition of crystalline CaB_6O_(10) at 900 ℃.
CaB_6O_(10)·5 H_2O was synthesized by hydrothermal method at 120 ℃ with using boric acid and lime as materials.The thermal analysis of CaB_6O_(10)·5 H_2O showed that CaB_6O_(10)·5 H_2O was dehydrated by 4 steps,one exothermic peak near 800 ℃and one endothermic peak near 900 ℃ were found,respectively.The high temperature phase transition behavior of CaB_6O_(10)·5 H_2O was discussed by chemical analysis,XRD,TG-DTA and IR analysis.The results indicated that:the first crystalline CaB_6O_(10)·5 H_2O was converted to amorphous CaB6 O10 at 600 ℃,and the amorphous CaB_6O_(10) was converted to crystalline CaB6 O10 at 800 ℃,and finally CaB4 O7 and vitreous B2 O3 were obtained by the decomposition of crystalline CaB_6O_(10) at 900 ℃.
引文
[1]吴以成.B3O7基团型硼酸盐非线性光学晶体研究进展[J].人工晶体学报,2001,30(1):43-48.
[2]王文侠.四水合六硼酸钙的合成研究[J].天津化工,2002(4):23-24.
[3]王凯,于天明,仲剑初,等.由硼砂和消石灰制备偏硼酸钙[J].无机盐工业,2009,41(4):31-34.
[4]曹惠峰.水热法合成硼酸钙的工艺研究与性能表征[D].景德镇:景德镇陶瓷学院,2007.
[5]王斐,仲剑初,胡德生,等.水热法解聚钠硼解石制备硼酸钙[J].无机盐工业,2007,39(9):27-30.
[6]左传凤.水合硼酸钙的合成及其热化学研究[D].西安:陕西师范大学,2005.
[7] Gode H.Calcium hexaborate[J].Latvijas PSR Zinatnu Akademijas Vestis,1949,27(10):101-106.
[8] Chen X,Li M,Chang X,et al.Synthesis and crystal structure of a new calcium borate,Ca B6O10[J].Journal of Alloys and Compounds,2008,464(1/2):332-336.
[2]王文侠.四水合六硼酸钙的合成研究[J].天津化工,2002(4):23-24.
[3]王凯,于天明,仲剑初,等.由硼砂和消石灰制备偏硼酸钙[J].无机盐工业,2009,41(4):31-34.
[4]曹惠峰.水热法合成硼酸钙的工艺研究与性能表征[D].景德镇:景德镇陶瓷学院,2007.
[5]王斐,仲剑初,胡德生,等.水热法解聚钠硼解石制备硼酸钙[J].无机盐工业,2007,39(9):27-30.
[6]左传凤.水合硼酸钙的合成及其热化学研究[D].西安:陕西师范大学,2005.
[7] Gode H.Calcium hexaborate[J].Latvijas PSR Zinatnu Akademijas Vestis,1949,27(10):101-106.
[8] Chen X,Li M,Chang X,et al.Synthesis and crystal structure of a new calcium borate,Ca B6O10[J].Journal of Alloys and Compounds,2008,464(1/2):332-336.