两性纳米颗粒表面的电荷调控介导相互作用
Charge Regulation Mediated Interaction of Amphoteric Nanoparticle Surfaces
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- Indian Institute of Technology, Jodhpur（印度理工学院乔德普尔分校）
- Université Grenoble Alpes, CNRS, Grenoble INP, 3SR（格勒诺布尔阿尔卑斯大学）
- Vellore Institute of Technology（维洛尔理工大学）
机构由 AI 辅助整理，请以论文原文为准。
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中文总结 AI 辅助
该研究通过显式离子模拟揭示电荷调控可显著增强不对称纳米颗粒的短程吸引并改变对称颗粒间作用符号，对胶体组装稳定性有重要影响。
中文摘要 AI 辅助
电荷调控是指可电离生物分子及其对应物响应外部扰动（包括pH值、离子强度的变化或与邻近带电物种的静电相互作用）而调整其电离状态的能力。在此，我们使用显式离子分子动力学/电荷调控蒙特卡洛模拟来计算两个球形、电荷调控纳米颗粒之间的相互作用力随分离距离的变化，并将对称（化学相同）和不对称（化学互补）表面构型与恒定电荷近似进行比较。我们发现，对于不对称纳米颗粒对，电荷调控产生的短程吸引力比恒定电荷强达一个数量级，尤其是在低电解质浓度下；并且电荷调控定性改变了对称、化学相同纳米颗粒之间的相互作用，随着离子强度降低，驱动从净排斥到净弱吸引的交叉转变。在恒定电荷假设下未观察到这种转变，这表明电荷调控不是一个小修正，而是可以改变纳米尺度静电相互作用的强度和符号，对电荷调控胶体系统的组装和稳定性具有重要意义。
英文摘要
Charge regulation refers to the ability of ionizable biomolecules and their counterparts to adjust their ionization state in response to external perturbations, including changes in pH, ionic strength, or electrostatic interactions with neighboring charged species. Here, we use explicit-ion molecular dynamics / charge-regulation Monte Carlo simulations to compute the interaction force between two spherical, charge-regulated nanoparticles as a function of separation, and compare symmetric (chemically identical) and asymmetric (chemically complementary) surface configurations against the constant charge approximation. We find that charge regulation produces up to an order-of-magnitude stronger short-range attraction than constant charge for asymmetric nanoparticle pairs, particularly at low electrolyte concentration, and that charge regulation qualitatively alters the interaction between symmetric, chemically identical nanoparticles, driving a crossover from net repulsion to net weak-attraction as ionic strength decreases. This transition is not observed under the constant charge assumption which shows that charge regulation is not a minor correction but can change both the strength and the sign of nanoscale electrostatic interactions, with implications for the assembly and stability of charge-regulated colloidal systems
