纳米ZnO粉体在聚丙烯酰胺乳胶液中的微波诱导分散

用水和甲醇溶解聚丙烯酰胺(PAM)粉末制备 PAM 乳胶液,将纳米氧化锌粉体按一定量的比例加入 PAM 乳胶液中,在微波场中进行纳米氧化锌粉体在 PAM 乳胶液中的分散性能研究。实验条件为:微波功率 400～500 W, 搅拌时间 30 min,搅拌强度 600 r?min?1。用 TEM 技术进行纳米氧化锌粉体在 PAM 乳胶液中的分散性能表征。 PAM乳胶液中纳米 ZnO 颗粒的 TEM 照片(放大 58×103~100×103倍)表明,在微波场作用下,纳米氧化锌颗粒在 PAM 乳胶液中团聚程度非常小,大部分颗粒的粒径在 40~70nm 范围内。微波作用能够显著改善纳米 ZnO 粉体在 PAM 乳胶液中的分散性能的机理被认为是,在微波场作用下,纳米 ZnO 颗粒表面上的微晶俘获或束缚周围的空间电荷或带电离子和基团,使其附在纳米 ZnO 颗粒的表面形成保护层,从而抑制了纳米 ZnO 粉体在 PAM 乳胶液中的团聚。

Microwave-induced Dispersion of Nano-ZnO Powder in Polyacrylamide Colloid

Microwave-technology was used to enhance the dispersion of nano-ZnO powder in polyacrylamide (PAM) colloid. The PAM colloid was obtained by dissolving PAM powder into the solvents of water and methanol. The powder of nano-ZnO was put into the PAM colloid with a certain content. The dispersion of nano-ZnO powder in the colloid of PAM was carried out in the field of microwave with stirring under the conditions of microwave power 400~500W, stirring time 30 min and stirring rate 600 r?min-1. The characterization of the dispersion of nano-ZnO powder in the colloid of PAM was done by TEM. The TEM photos of nano-ZnO particles in PAM colloid showed that under the condition of microwave-induced dispersion, the content of the aggregation of nano-ZnO particles in PAM colloid is very low compared with that in the condition of stirring dispersion. After the microwave-induced dispersion, the sizes of the most of nano-ZnO particles in PAM colloid are among 40~70nm. It is suggested that in the field of microwave the microcrystals on the surface of nano-ZnO may absorb ions or groups with charge, yielding protection layer, therefore prohibit the aggregation of nano-ZnO particles in PAM colloid.