Attractive Electrostatic Forces between Identical Colloidal Particles Induced by Adsorbed Polyelectrolytes

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• 作者：Ionel Popa ; Graeme Gillies ; Georg Papastavrou ; Michal Borkovec
• 刊名：Journal of Physical Chemistry B
• 出版年：2009
• 出版时间：June 25, 2009
• 年：2009
• 卷：113
• 期：25
• 页码：8458-8461
• 全文大小：232K
• 年卷期：v.113,no.25(June 25, 2009)
• ISSN：1520-5207

文摘

Polyelectrolytes adsorb strongly at oppositely charged surfaces, thereby dramatically influencing the corresponding interaction forces. In this letter, we report on direct force measurements with the atomic force microscope (AFM) between two individual particles in an aqueous colloidal suspension in the presence of polyelectrolytes near the isoelectric point. From systematic variations of the molecular mass, the ionic strength, and analysis of adhesion events, we conclude that the observed attractive forces are mainly due to electrostatic patch-charge interactions. The same type of attractive forces is equally influencing interactions between proteins as well as hydrophobic or mineral surfaces.