Determining the boundary conditions governing phase separation processes of borate-glass systems

硼酸盐玻璃中的不混溶是一种普遍现象。进行了一系列的实验研究，在钠盐玻璃中添加了金属氧化物(非二氧化硅)。对于Na_20-B_2O_3-Y_2O_3-ZrO_2系玻璃，经过热处理和选择性浸出后，得到了多孔玻璃。目前，在含金属氧化物的硼酸盐玻璃中制备多孔玻璃的微结构形成过程还没有得到系统的研究，尤其是含CeO2和/或ZrO2的含钠硼酸盐玻璃。为此，正在研究两个三元体系(ZrO2-Na2O-B2O，CeO2-Na2O-B2O)和一个四元体系(ZrO2-CeO2-Na2O-B2O)。这些研究主要集中在三个方面：确定玻璃成分对热性能和物理性质的影响，分相过程的基础研究，以及研究浸取条件对合成不同成分的多孔玻璃的影响。该项目的目标是更深入地了解硼酸盐玻璃中微结构的形成过程，以获得由大量金属氧化物组成的新的多孔玻璃。这些多孔玻璃有可能开发出一种新型的多孔微晶玻璃：可控多孔微晶玻璃。

Immiscibility in borate glasses is a common phenomenon. A series of experimental studies have been carried out, where sodium borate glasses were enriched with metal oxides (non-silica). In the case of Na20-B2O3-Y203-Zr02 glasses, a porous glass was obtained after heat treatment and selective leaching. To our present knowledge no systematic investigations of the rather complex microstructure forming processes in metal oxide containing borate glasses to produce porous glasses have been carried out.This especially include ZrO2 or/and CeO2 containing sodiumborate glasses. To this end, two ternary systems (ZrO2-Na2O-B2O3, CeO2-Na2O-B2O3) and one quaternary system (ZrO2-CeO2-Na2O-B2O3) are under investigation. The studies focus on three main topics: Determination of the Impact of glass composition on thermal and physical properties, fundamental research on phase separation processes and the investigation of the impact of leaching conditions to synthesize porous glasses with different compositions. The goal of this project is to gain a deeper understanding of the microstructure forming processes in borate glasses to obtain “new” porous glasses consisting of high amounts of metal oxides. These porous glasses have the potential to develop a new kind of porous glass ceramics: the controlled porous glass ceramics.