聚合物水化分子的微观结构研究

在聚合物水化分子微观结构研究中，必需使用冷冻升华方法制样才能基本保持样品的聚合物分子形态与原水化状态一致。风干制样方法会导致聚合物分子链卷缩，样品干缩成块，无法保留水化分子的原貌。放大倍数小于2000X的显微图像适于研究聚合物水化分子构成的骨架全貌；而放大倍数大于10000X后，更适于观察聚合物水化分子骨架的局部形态。聚合物分子在溶液中形成非均匀网络骨架，存在较粗的主干和较细的分枝。这种网络骨架既对水分子形成支撑，又吸附和包裹大量水分子产生形变阻力。大部分网络骨架不是由单个聚舍物分子构成，而是由聚合物分子聚集体形成。溶液中的盐份富集在聚合物分子的带电基团附近并形成浓度梯度分布。

Study on the microstructure of polymer molecule hydrate

One of key points for the microstructure study of polymer molecule hydrates is to keep the shape of polymer molecule in the sample consisting with that in solution.Polymer chains will shrink and samples desiccate to congregate in a simple process of air drying, and could not retain the shape of polymer molecule hydrates.But, this problem could be basically solved with a method in which polymer solution or gel samples are frozen in liquid nitrogen, and then sublimated in a vacuum freezedryer.The microscopic images with a magnification lower than 2 000X are suitable to study the panorama of skeletons formed with polymer molecule hydrate.It is better for the observation of fine conformation of polymer molecule hydrates when the magnification is higher than 10 000X.The ununiformity net skeletons formed with polymer molecules in solution, in which there were thick backbones attached with thin branches.This kind of net skeletons either sustain water molecules or adsorbed and wrapped to produce resistance to deformation.Most skeletons were not built up with single polymer molecule linking together, but with the aggregations of polymer molecules.Salts are enriched around electriferous groups of polymer molecules in solution, which formed a salt concentration gradient.