- 學位論文
無鉛低熔點SnO-ZnO-P2O5玻璃之化學耐蝕性
Chemical durability of a low melting, lead free SnO-ZnO-P2O5 glass
摘要
本論文擬研究無鉛低溫封合60SnO-10ZnO-30P2O5 (mol%)玻璃之化學耐蝕性。實驗為改變不同試片總表面積對溶液體積比對化學耐蝕性的影響，藉由測量溶液中離子濃度變化與觀察腐蝕表面結構分析。 隨著試片總表面積與溶液體積的比值越大，玻璃腐蝕之單位面積重量損失及溶出濃度減少。玻璃在溶液中先溶出玻璃修飾劑，再破壞以(PO4)3-四面體為主的直鏈狀結構。 由表面光譜分析可看出此成份玻璃結構為pyro-磷酸鹽，並以SnO連接形成的鏈狀。隨著腐蝕過程中，水分子攻擊以(PO4)3-四面體為主之長鏈狀結構，使P－O斷鍵形成鏈狀結構溶出。 此玻璃並不是均勻腐蝕，其可能原因為部份SnO氧化成為SnO2，使結構較完整不易溶出。
並列摘要
This thesis is devoted to investigate the chemical durability of the lead-free, low-melting 60SnO-10ZnO-30P2O5 (mole%) glass in water. Effects of the sample surface-area on the dissolution rate, ion concentrations in the reacting solution, and the change in glass structure were studied. When the sample surface-area increased, the weight loss per unit area and ion concentrations per unit area decreased. The major species first dissolved in the initial stage of reaction was the modifier Zn2+, followed by the breakdown of chain structure of (PO4)3- tetrahedron. According to the structure analysis, the original glass has the pyro-phosphate structure, in which the chains of (PO4)3- tetrahedron were cross-linked by Sn2+ and Zn2+. The chain structure was attacked by water molecule during dissolution. The dissolution of glass was not homogeneous over the sample surface, resulted from the possible oxidation of some Sn2+ to Sn4+ in the less-etched region.