Nanoparticle Adsorption on a Weak Polyelectrolyte. Stiffness, pH, Charge Mobility, and Ionic Concentration Effects Investigated by Monte Carlo Simulations

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• 作者：Serge Ulrich ; Marianne Seijo ; Abohachem Laguecir ; Serge Stoll
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：October 26, 2006
• 年：2006
• 卷：110
• 期：42
• 页码：20954 - 20964
• 全文大小：534K
• 年卷期：v.110,no.42(October 26, 2006)
• ISSN：1520-5207

文摘

Monte Carlo simulations have been used to study two different models for a weak linear polyelectrolyte inthe presence of nanoparticles: (i) a rodlike and (ii) a flexible polyelectrolytes. The use of simulated annealinghas made it possible to simulate a polyelectrolyte chain in the presence of several nanoparticles by improvingconformation sampling and avoiding multiple minima problems when dense conformations are produced.Nanoparticle distributions along the polymer backbone were analyzed versus the ionic concentration,polyelectrolyte stiffness, and nanoparticle surface charge. Titration curves were calculated and the influencesof the ionic concentration, solution pH, and number of adsorbed nanoparticles on the acid/base polyelectrolyteproperties have been systematically investigated. The subtle balance of attractive and repulsive interactionshas been discussed, and some characteristic conformations are presented. The comparison of the two limitmodels provides a good representation of the stiffness influence on the complex formation. In some conditions,overcharging was obtained and presented with respect to both the polyelectrolyte and nanoparticle as thecentral element. Finally, the charge mobility influence along the polyelectrolyte backbone was investigatedby considering annealed and quenched polyelectrolyte chains.