| Summary: | 碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 96 === The hydroxyl content in phosphate glass system has the significant influence to the glass nature. This research is substituting zinc chloride for zinc oxide of the glass, reduces the hydroxyl content of the phosphate glass, and it has the influence of the thermal property, optical property and water durability of the glasses were discussed. Zinc chloride as the dehydroxylating agent, and substitute it for ZnO of the glasses, will reduce the hydroxyl content of the glasses, improving vitreous water durability. It also raises glass transition temperature and UV transmittance, and the UV cutoff shifts towards the shorter wavelength (199nm). The optical bandgap energies of two series glasses are also raising, because of substituting ZnCl2 for ZnO of the glasses.
The structural changes with the glass compositions were gauged by FTIR and 31P MAS�{NMR spectroscopies. FTIR spectra indicated that lengthening the P�{O�{P chainlength with substituting ZnCl2 for ZnO of the two glass systems. 31P MAS�{NMR spectra indicated that increasing the Q2 units with substituting ZnCl2 for ZnO of the two glass systems.
The investigation of crystallization behavior in the 50P2O5�{47ZnO�{3 ZnCl2 glass was carried out by a differential thermal analysis technique (DTA) and X-ray diffration detector (XRD). Analyzing by instruments, it can get the kinetics parameters. Then using the kinetics equations can be calculated the activation energies and avrami exponent of the 50P2O5�{47ZnO�{3ZnCl2 glass. The range of activation energies from 113.9 to 130.8 kJ/mol, the avrami exponent is 1.17 of this glass, they indicated that the 50P2O5�{47ZnO�{3ZnCl2 glass had the characteristics of low activation energy and surface crystallization.
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