Macroion correlation effects in electrostatic screening and thermodynamics of highly charged colloids.
Macroion correlation effects in electrostatic screening and thermodynamics of highly charged colloids.
复制标题
高电荷胶体静电屏蔽和热力学中的宏离子相关效应。
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
J. C. Mixteco
中科院分区：
文献类型：
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作者：
R. Castañeda;L. F. Rojas;V. Lobaskin;J. C. Mixteco
利用平均场理论和原始模型计算机模拟研究了巨离子相关对高电荷胶体悬浮液热力学的影响。我们提出了一种简单的方法，将宏离子相关性纳入平均场理论，作为Trizac和Levin [Phys]的重整化凝胶模型的扩展。Rev. 69,031403(2004)]。然后，将从平均场方法中提取的有效筛选参数用于一个单组分模型中，该模型通过汤川势相互作用来预测宏离子分布。我们发现，与其他平均场模型相比，包含大离子相关性导致较弱的筛选，因此更小的有效大离子电荷和更低的胶体分散渗透压。这一结果得到了原始模型模拟和低盐状态下带电大离子实验的支持，在低盐状态下，大离子的相关性预计是显著的。
We study macroion correlation effects on the thermodynamics of highly charged colloidal suspensions using a mean-field theory and primitive model computer simulations. We suggest a simple way to include the macroion correlations into the mean-field theory as an extension of the renormalized jellium model of Trizac and Levin [Phys. Rev. E 69, 031403 (2004)]. The effective screening parameters extracted from our mean-field approach are then used in a one-component model with macroions interacting via a Yukawa-like potential to predict macroion distributions. We find that inclusion of macroion correlations leads to a weaker screening and hence smaller effective macroion charge and lower osmotic pressure of the colloidal dispersion as compared to other mean-field models. This result is supported by comparison to primitive model simulations and experiments for charged macroions in the low-salt regime, where the macroion correlations are expected to be significant.