玻璃微球壁厚和预充气工艺对气体渗透性能的影响

Influence of wall thickness and filling gas procedure on permeability of hollow glass microsphere

以空心玻璃微球为研究对象,利用高压充气系统充气,测量了不同条件下玻璃微球对氘气在室温条件下的气体渗透系数。研究结果表明:微球的壁厚对气体渗透系数影响较大,2μm以上厚壁球的气体渗透系数约5.0×10-22mol.m-1.s-1.Pa-1,而壁厚小于1μm时,渗透系数约1.56×10-20mol.m-1.s-1.Pa-1,两者相差30倍。预充气挑选工艺对微球的气体渗透系数也产生一定影响,对于薄壁空心玻璃微球一次充放气气体渗透系数增加约50%,两次充放气则增大一倍左右。对上述影响因素进行了初步的探讨,气体渗透系数改变的主要原因是玻璃微球表面的结构裂纹、空位和缺陷。

The influence of the wall thickness and filling gas procedure on the permeability of the hollow glass microspheres （HGM） were discussed. The primary experiments show that the deuterium permeation coefficient was 5. 0 ×10^22mol·m^-1·s^-1·Pa^-1 with the wall thickness more than 2 μm at room temperature, while it was 1.56 ×10^22mol·m^-1·s^-1·Pa^-1 with the wall thickness less than 1 μm. The permeation coefficient of thin wall HGM increased 30 times more than that of thick one. The main reason for the effect of the wall thickness on the HGM permeability was microcrack on the HGM surface. The permeation coefficient increases about 50 % if HGM experienced one cycle of filling and deflating gas, and doubles after two cycles owing to the voids and flaws on the HGM surface caused by high temperature and gas permeation.