二维衰减全反射红外光谱研究水在聚酰亚胺/二氧化硅纳米高分子复合膜中的吸附扩散行为

考虑到基于聚酰亚胺衍生物的电子器件的稳定性和性能,运用二维衰减全反射红外相关光潜研究了水在聚酰亚胺衍生物:poly(4’4- oxydiphenylene pyromellitimide)和二氧化硅的纳米高分子复合膜中的动态吸附和扩散行为．二维相关光谱区分出了三种不同氢键强度的水分子状态,同时,氢键的数量和强度还对不同状态水分子的扩散速率起了决定性的作用,和PI聚合物本身以及PI表面残留的硅酸形成氢键的水分子的扩散速度则最慢.

Two-dimensional ATR-FTIR Spectroscopic Study on the Water Di?usion Behavior in Polyimide/silica Nanocomposite

To consider the reliability and performance of electronic devices based on polyimide derivatives, dynamic water sorption and diffusion behavior in a polyimide derivative: poly(4'4-oxydiphenylene pyromellitimide) (PMDA-ODA)/silica nanocomposite was investigated by two-dimensional ATR-FTIR spectroscopy, by which three states of water molecules owning different H-bonding strength were distinguished. The amounts and strength of H-bonding also played a significant role in determining the diffusion rate of the different states of water molecules. The type of aggregated water molecules which also formed H-bonding with silicic acid (residues) or polyimide system was the last one diffusing to the polymer side in contact with the ATR crystal element because the polymeric matrix blocked their diffusion to a great extent. The diffusion coefficient was also estimated to gain the information of the dynamic diffusion behavior.