Analysis of electrosteric interaction of polymer dispersant in dense alumina suspensions with different counter-ion densities using an atomic force microscope
Analysis of electrosteric interaction of polymer dispersant in dense alumina suspensions with different counter-ion densities using an atomic force microscope
复制标题
使用原子力显微镜分析不同反离子密度的致密氧化铝悬浮液中聚合物分散剂的电空间相互作用
DOI：
10.2109/jcersj.109.1270_516
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发表时间：
2001
影响因子：
1.1
通讯作者：
H. Kamiya
中科院分区：
文献类型：
--
作者：
Y. Fukuda;Tsunetaka Togashi;M. Naito;H. Kamiya
The mechanism of anionic polymer dispersant acting on dense alumina suspension behavior was analyzed under different solid-volume fractions (ranging from 40 to 55vol%) and counter-ion densities by comparing microscopic solid/liquid interface interaction to suspension viscosity. The solid/liquid interface interaction and adsorbed structure of polymer dispersant on particles were determined by an atomic force microscope (AFM). The dependency of counter-ion density on the suspension viscosity appeared at a relatively low solidvolume fraction (40vol%). However, at a high solid-volume fraction (50vol%), the suspension viscosity was independent of the counter-ion density. To analyze these phenomena, the force curves between a polished surface of alumina and the tip of AFM were measured in solution with polymer dispersant and different counter-ion densities. The increase of counter-ion density reduced the long-range overlapping repulsive force of an electrical double layer ranging over 10nm in surface distance. A short-range steric repulsion force ranging below about 5nm in surface distance slightly depended on counter-ion density. The estimated mean surface distance between particles in dense suspension decreased from about 8 to 4nm with increasing the solid fraction from 40 to 50vol%. Based on both results, it is concluded that the main mechanism for the aggregation/dispersion of alumina powder in dense suspension changed from electrostatic repulsive force to steric force with increasing the solid-volume fraction in suspension.
