Solventless synthesis of bismuth-free and lead-free low-melting glasses

我们最近开发了低熔点有机-无机杂化硅磷酸盐玻璃，它是由正磷酸和有机改性的氯硅烷在低温(&lt；300℃)下混合而成的。这些玻璃能够溶解稀土离子和有机分子，这表明它们可能是光学设备的良好主体材料。由于大气中的耐水性较低，因此本研究的目的是提高玻璃的耐水性。通过量子化学计算，提出了玻璃的水解反应机理。根据这一结果，我们得出结论，玻璃形成过程中产生的磷酸和/或盐酸对水解液的催化作用是有帮助的。我们还以正磷酸和有机改性烷氧基硅烷为原料进行了无HCl反应，制备了耐水性低熔点玻璃，并在此基础上制备了具有大量均匀分散磷基团的有机-无机杂化磷硅酸盐薄膜。热重和交流阻抗谱表明，该膜是一种潜在的质子导电膜。

We have recently developed the low-melting organic-inorganic hybrid silicophosphate glasses, which are prepared by mixing orthophosphoric acid with organically-modified chlorosilane at low temperature (<300℃). These glasses are capable of dissolving both rare earth ions and organic molecules, suggesting that they may be good host material candidates for optical devices. Because of the low water resistance in the atmosphere, the purpose of this study is to improve the water resistance of glasses. We proposed the hydrolytic reaction mechanism of the glasses using quantum chemical calculations. Based on this result, we concluded that the hydrolysis is assisted by acid derived from phosphoric acid and/or hydrochloric acid generated during the glass formation reaction. We also developed HCl-free reaction using orthophosphoric acid and organically-modified alkoxysilane as starting reagents to prepare the water-durable low-melting glasses.Additionally, we have also prepared an organic-inorganic hybrid phosphosilicate membrane with a lot of uniformly-dispersed phosphoric groups based on this method. Thermogravimetric and AC impedance spectroscopy have revealed that the present membrane is a potential candidate for the proton-conducting membrane.