偏二甲肼在氟化镁涂层表面的吸附与反应

研究了偏二甲肼在氟化镁涂层表面的吸附和化学反应情况.首先用液相或气相偏二甲肼沾染氟化镁涂层表面,再将涂层置于真空环境足够长时间,然后通过对比沾染前、后涂层表面的红外吸收光谱、X射线光电子能谱和漫反射率,了解涂层表面的吸附状况和性能变化.实验表明,覆盖于氟化镁涂层表面的偏二甲肼液膜分子,在真空环境下充分脱附的时间约为2h,充分脱附后的涂层表面只有单层化学吸附存在,其质量密度约为27ng/cm2,实验后氟化镁涂层表面的漫反射率下降了10%～15%;在-10℃的偏二甲肼饱和蒸气中沾染10min后,氟化镁涂层表面的原子组成和漫反射率变化很小,红外吸收光谱也没有偏二甲肼特征峰出现.

Absorption and Reactions of 1,1-dimethyl-hydrazine on the Surface of Magnesium Fluoride Coating

The absorption and chemical reactions of 1,1-dimethyl-hydrazine(C_2H_8N_2) on the surface of magnesium fluoride(MgF_2) coating was studied. The coating surface is firstly contaminated by liquid or gaseous C_2H_8N_2 , and then it is placed into a vacuum environment for a long period. Contrasting the infrared absorption spectra, ~X-ray photoelectron energy spectra and diffusive reflectivity of MgF_2 coating surfaces before and after experiment, it may be learned that the absorption and chemical reactions occur at the surface. The experimental results show that the molecules of a liquid film of C_2H_8N_2 over MgF_2 coating surface take about two hours to desorb adequately in a vacuum environment, after the adequate desorption, there only exists a single chemical absorption layer over the coating surface, with a mass density of about 27 ng/cm2. The diffusive reflectivity of MgF_2 coating surface decreases about 10%-15% after the contamination of liquid C_2H_8N_2. For MgF_2 coating surfaces immersed in C_2H_8N_2 vapor at the pressure of 3 kPa for ten minutes, there are neither changes in their atomic constitution and diffusive reflectivity, nor characteristic peaks of C_2H_8N_2 appear in their infrared absorption spectrum.