Adsorption of heterogeneously charged nanoparticles on a variably charged surface by the extended surface complexation approach: Charge regulation, chemical heterogeneity, and surface complexation
Adsorption of heterogeneously charged nanoparticles on a variably charged surface by the extended surface complexation approach: Charge regulation, chemical heterogeneity, and surface complexation
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DOI：
10.1021/jp076621x
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发表时间：
2008-02-07
影响因子：
3.3
通讯作者：
Tanaka, Satoru
中科院分区：
文献类型：
--
作者：
Saito, Takumi;Koopal, Luuk K.;Tanaka, Satoru
随机支化的聚电解质、“毛状”粒子和内部结构的大分子，统称为异质带电纳米粒子，在带电表面上的吸附是重要的。许多技术和自然过程。在本论文中，我们将重点研究(1)纳米粒子和表面的电荷调节以及(2)粒子官能团和表面位置之间的表面络合作用，并将用扩展的表面络合方法从理论上研究吸附。该模型显式地考虑了具有平均(涂抹)结构和电荷的纳米粒子的电化学势，以获得平衡吸附。粒子的化学非均质性用质子化常数的分布来描述。对吸附的纳米颗粒化学势的详细分析表明，吸附的pH和盐度依赖于颗粒和表面电荷调节以及表面络合所产生的能量增益和靠近表面的不利颗粒间静电斥力所产生的能量损失之间的平衡。这一结论也得到了颗粒官能团的化学异质性、表面络合的大小、官能团的数量和颗粒的大小对吸附的强烈影响的支持。
Adsorption of randomly branched polyelectrolytes, "hairy" particles and internally structured macromolecules, collectively denoted as heterogeneously charged nanoparticles, on charged surfaces is important in. many technological and natural processes. In this paper, we will focus on (1) the charge regulation of both the nanoparticle and the surface and (2) the surface complexation between the particle functional groups and the surface sites and will theoretically study the adsorption using the extended surface complexation approach. The model explicitly considers the electrochemical potential of a nanoparticle with an average (smeared-out) structure and charge both in bulk solution and on the surface to obtain the equilibrium adsorption. The chemical heterogeneity of the particle is described by a distribution of the protonation constant. Detailed analysis of the chemical potential of the adsorbed nanoparticle reveals that the pH and salt dependence of the adsorption can be largely explained by the balance between an energy gain resulting from the particle and surface charge regulation and the surface complexation and an energy loss from the unfavorable interparticle electrostatic repulsion close to the surface. This conclusion is also supported by the strong impacts that the chemical heterogeneity of the particle functional groups, the magnitude of the surface complexation, the number of the functional groups, and the size of the particle have on the adsorption.