Sol-Gel法制备非晶态SiO_2玻璃光纤预制棒“干胶”工艺研究

The Process Research of the Amorphous SiO_2 Fibre-optical Perform Gel with SOL-GEL Method

为采用Sol-Gel法制备低廉的SiO2光纤预制棒芯棒,讨论了以正硅酸乙酯为硅源,乙醇和水的混合物为溶剂,盐酸和甲酰胺为添加剂,用Sol-Gel法制备非晶态SiO2干胶的制备工艺.用XRD衍射仪等进行测试,结果表明,干胶的显微结构为SiO2非晶态,主要化学成分是Si和O.同时探讨了添加剂、热处理温度等制备工艺对生成的非晶态SiO2光纤预制棒"干胶"性能的影响.实验表明,溶胶加热温度在90℃、凝胶热处理温度为110℃、溶液配比为正硅酸乙酯:乙醇:水=1∶4∶8、加入适量的盐酸和甲酰胺,SiO2干胶透明度、纯度和减少裂纹扩展情况最佳.

In this paper, we researched the producing technology of SiO2 gel which adopt sol-gel process method prepared from the tetraethoxysilane as raw materials, and in which alcohol and water as solvent, formylamine and hydrochloric acid as additives. The SiO2 gel microstructure, the chemistry bond and the phase structure were characterized by means of XRD （X-ray diffraction instrument）, SEM （scanning electricity mirror） and XPS. The result showed that the gel SiO2 is an amorphous state, main element chemical compositions are Si and O. Study the influence of the additive and the heat treatment temperature process on the SiO2 preform. Experiment research indicated： the system was layered when the hydrochloric acid added relatively minor, with increasing of the hydrochloric acid amount the gel time become shorten, then turbidness appeared. Adding formylamine can reduce the tiny crack amount of gel effectively, the more the formylamine amounts, the less the gel transparency. In the process of heat treatment, when the temperature is high, the warming increase rapidly, and more tiny cracks and air cavities generated. Conclusion ： the heat temperature of the Sol is 90℃, and the temperature of heat treatment of the gel is 110 ℃, the ratio of tetraethoxysilane： Alcohol： Water = 1：4： 8, adds the appropriate amount hydrochloric acid and formylamine, SiO2 gel can reach good transparency and synthetical performance.