PS纳米球在羧甲基化壳聚糖自组装膜表面静电吸附行为研究

用AFM研究了PS纳米球在自组装有羧甲基化壳聚糖(CM-CHI)单层膜的云母基底上的吸附行为及CM-CHI自组装膜形貌对PS纳米球吸附行为的影响.重点考察了盐浓度,吸附时间和温度对PS自组装动力学的影响.在CM-CHI自组装膜制备条件一定的情况下,20℃时PS最大覆盖率对应的盐浓度为0.5mol/L,平衡吸附时间为20min,对应的覆盖率约为48.0%.CM-CHI自组装膜形貌对覆盖率的影响主要表现为PS纳米球在由不同方法制备的CM-CHI自组装膜上的覆盖率在最宜吸附盐浓度,平衡吸附时间内随吸附温度的升高而显著增大,当PS吸附温度为60℃时甚至有部分覆盖率达65.0%.此外,还讨论了有关CM-CHI自组装膜是否干燥及PS自组装循环中冲洗用水盐浓度对PS纳米球覆盖率的影响.

ELECTROSTATIC ADSORPTION OF SURFACE CHARGED POLYSTYRENE NANOSPHERES ON CARBOXYMETHYLATED CHITOSAN SELF ASSEMBLED MONOLAYER

Atomic force microscopy (AFM) was chosen to investigate the electrostatic adsorption of PS nanospheres on carboxymethylated chitosan (CM-CHI ) self assembled monolayer,and the effect of the morphology of CM-CHI self assembled monolayer on the adsorption of PS nanospheres.The concentration of electrolyte,adsorption time and temperature of the process of PS adsorption were especially concerned in the adsorption kinetics study.For the CM-CMI self assembled monolayer prepared under the same condition,the respective electrolyte concentration for maximal coverage rate (Rc),48.0% at 20℃ is 0.5 mol/L,and the time for equilibrium adsorption is 20 min.The effect of the morphology of CM-CHI self assembled monolayers on the Rc was represented by the rapid increase of Rc with the rise of adsorption temperature.The reason of this phenomenon was discussed thoroughly in this paper.The drying process of carboxymethylated chitosan self assembled monolayer and the washing process of PS nanosphere adsorption were also discussed to investigate their contribution to the Rc.