Ion-ion correlation, solvent excluded volume and pH effects on physicochemical properties of spherical oxide nanoparticles.
Ion-ion correlation, solvent excluded volume and pH effects on physicochemical properties of spherical oxide nanoparticles.
复制标题
DOI：
10.1016/j.jcis.2015.10.019
复制
发表时间：
2016-01-15
影响因子：
9.9
通讯作者：
Marucho M
中科院分区：
文献类型：
--
作者：
Ovanesyan Z;Aljzmi A;Almusaynid M;Khan A;Valderrama E;Nash KL;Marucho M
在水性电解质中实施纳米颗粒的复杂性的一个主要来源来自于生物环境对其物理化学性质的强烈影响。理解控制纳米颗粒物理化学性质的分子机制的一个关键参数是表面电荷密度的形成。在这篇文章中，我们提出了一个有效的和准确的方法，结合了最近推出的经典溶剂化密度泛函理论的球形双电层与表面络合模型来解释离子-离子相关性和排除体积效应的表面滴定的球形纳米粒子。我们应用所提出的计算方法来解释球形二氧化硅（SiO2）纳米颗粒表面化学的电荷调节机制。我们分析了纳米粒子的粒径、水溶液的pH值和电解质浓度对纳米粒子表面电荷密度和Zeta电位的影响。我们验证了我们的预测为580纳米粒子和200纳米粒子浸泡在酸性，中性和碱性一价水电解质溶液对实验数据。我们的研究结果表明，排除体积和离子-离子的相关性有助于显着的表面电荷密度和Zeta电位的纳米粒子在高电解质浓度和pH值水平，其中溶剂拥挤效应和静电屏蔽已显示出深刻的影响质子化/去质子化反应在液体/溶质界面。这种方法在描述二氧化硅纳米粒子的物理化学性质方面的成功支持了其更广泛的应用，以研究其他球形金属氧化物纳米粒子。
One major source of complexity in the implementation of nanoparticles in aqueous electrolytes arises from the strong influence that biological environments has on their physicochemical properties. A key parameter for understanding the molecular mechanisms governing the physicochemical properties of nanoparticles is the formation of the surface charge density. In this article, we present an efficient and accurate approach that combines a recently introduced classical solvation density functional theory for spherical electrical double layers with a surface complexation model to account for ion-ion correlation and excluded volume effects on the surface titration of spherical nanoparticles. We apply the proposed computational approach to account for the charge-regulated mechanisms on the surface chemistry of spherical silica (SiO2) nanoparticles. We analyze theeffects of the nanoparticle size, as well as pH level and electrolyte concentration of the aqueous solution on the nanoparticle’s surface charge density and Zeta potential. We validate our predictions for 580 Å and 200 Å nanoparticles immersed in acid, neutral and alkaline mono-valent aqueous electrolyte solutions against experimental data. Our results on mono-valent electrolyte show that the excluded volume and ion-ioncorrelations contribute significantly to the surface charge density and Zeta potential of the nanoparticle at high electrolyte concentration and pH levels, where the solvent crowding effects and electrostatic screening have shown a profound influence on the protonation/deprotonation reactions at the liquid/solute interface. The success of this approach in describing physicochemical properties of silica nanoparticles supports its broader application to study other spherical metal oxide nanoparticles.