掺锂硼酸盐复合凝胶的制备与表征

 以硼酸三正丁酯、甲醇锂为主要原料，甲醇和四氢呋喃为溶剂，利用溶胶-凝胶法通过优化工艺制备了掺锂硼酸盐凝胶。分别采用粘度分析、热分析、X射线衍射、扫描电镜、透射电镜及红外光谱,对凝胶形成过程、物相、成分、微观形貌等进行表征。结果表明：对凝胶在150 ℃条件下处理4 h获得干凝胶，干凝胶在450 ℃左右产生结晶的倾向，492 ℃干凝胶已经完全从非晶态转变为晶态，在808 ℃左右晶体熔解；干凝胶是多孔网络结构材料；干凝胶网络结构的基本组成单元是以≡B—O—B=键的方式连接的，其中一个硼原子是四配位，另一个是三配位的。

Preparation and characterization of Li2O-B2O3 composite gel

Li_2O-B_2O_3 composite gels were successfully prepared from tri-n-butyl borate and lithium methoxide dissolved in methanol and tetrahydrofuran via sol-gel technique. Sol-gel process, micro-morphology, ingredient of the gel samples were characterized by viscosity analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, transmittance e-lectron microscopy and infra-red spectrum analysis. The results indicate that raw gel are dried after 4 h at 150 ℃ and crystallization is observed in the xerogels. Micro-morphology of Li_2O-B_2O_3 composite gels will transfer from non-crystal to crystal at about 492 ℃ , and the crystal liquates at about 808 ℃. The obtained dry gels are materials with porous configuration. The gel network appears to be composed of primary units linked exclusively by ≡B-O-B= bonds.