Department of Inorganic, Analytical, and Applied Chemistry, University of Geneva, Sciences II, 30, Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
J Colloid Interface Sci. 2011 Aug 15;360(2):580-5. doi: 10.1016/j.jcis.2011.04.106. Epub 2011 May 4.
Charging properties and colloidal stability of negatively charged polystyrene latex particles were investigated in the presence of linear poly(ethylene imine) (LPEI) of different molecular masses by electrophoresis and dynamic light scattering (DLS). Electrophoretic mobility measurements illustrate that LPEI strongly adsorbs on these particles leading to charge neutralization at isoelectric point (IEP) and charge reversal. Time-resolved DLS experiments indicate that the aggregation of the latex particles is rapid near the IEP and slows down away from this point. Surprisingly, the colloidal stability does not depend on the molecular mass, which indicates that the adsorbed LPEI layer is rather homogeneous.
通过电泳和动态光散射（DLS）研究了在不同相对分子质量的线性聚乙烯亚胺（LPEI）存在下，带负电荷的聚苯乙烯乳胶粒子的荷电性质和胶体稳定性。电泳迁移率测量表明，LPEI 强烈吸附在这些粒子上，导致等电点（IEP）处的电荷中和和电荷反转。时间分辨 DLS 实验表明，乳胶粒子的聚集在 IEP 附近迅速发生，并在远离该点时减慢。令人惊讶的是，胶体稳定性不依赖于相对分子质量，这表明吸附的 LPEI 层相当均匀。
