Understanding and exploiting ligand-driven nanoparticle interfacial phenomena

纳米粒子(NPs)如何与环境相互作用是我们许多最有前途的潜在纳米技术的核心问题：从设计和预测NPs在生命系统中的安全和有效使用，到形成可拉伸或自我修复的薄膜和复合材料，再到将纳米粒子组装成超结构，用于下一代太阳能电池、LED和其他应用。纳米粒子提供了一个复杂的界面，通过它可以与环境相互作用，这种复杂性源于各种可能的NP核心形状和大小，这些形状和大小反过来又定义了可用的表面化学和纳米粒子涂层的物理性质。在各种可合成的纳米粒子系统中，硫醇修饰的金纳米粒子是研究最深入的之一。尽管如此，关于NPs在不同环境条件下的行为仍然存在许多根本性的问题(即是什么使“好溶剂”好？这如何影响NPs与生物膜的相互作用？)这些问题是以前在这些系统中观察到的物理性质(溶解性和自组装)中经常观察到的反直觉趋势的核心。这项研究计划将提高我们对模型纳米粒子系统的物理性质(混合)的理解，该模型纳米粒子系统由不同金核尺寸和硫醇覆盖层密度的球形硫醇覆盖的金纳米颗粒组成。我们的目标是获得可应用于一般纳米颗粒的见解，随后将用于研究更复杂的纳米颗粒系统，该系统由两种类型的配体(疏水/亲水)和棒状纳米颗粒组成的混合盖层组成。通过控制界面参数(温度、油相或水相的溶剂化亲和力)，我们将阐明纳米粒子在不同环境中的一些关键性质，并为特定应用设计纳米粒子建立亟需的指南。

How nanoparticles (NPs) interact with their environment is a question that lies at the heart of many of our most promising potential nanotechnologies: from designing and predicting safe and effective use of NPs within living systems, to forming stretchable or self-healing films and composites, to assembling nanoparticles into superstructures for next generation solar cells, LEDs, and other applications. Nanoparticles present a complex interface through which they can interact with their environment, and this complexity arises from variety of possible NP core shapes and sizes which in turn define the available surface chemistry and the physical properties of the nanoparticle coating. Within the great variety of synthetically-available nanoparticle systems, thiol-capped gold nanoparticles are among the most thoroughly studied. Despite this fact, there remain many fundamental questions regarding how NPs behave in different environmental conditions (i.e. what makes a “good solvent” good? How can this influence how NPs interact with biological membranes?). Such questions are central to the counter-intuitive trends often observed in the physical properties (solubility and self-assembly) previously observed in these systems.This research program will improve our understanding of the physical properties (mixing) of a model nanoparticle system consisting of spherical thiol-capped gold nanoparticles of various gold core sizes and thiol capping layer densities. We aim to achieve insights that can be applied to nanoparticles in general, and subsequently will be used to study more complex nanoparticle systems consisting of mixed capping layers consisting of two types of ligands (hydrophobic/philic) as well rod-shaped nanoparticles. By controlling interfacial parameters (temperature, solvation affinity to the oil or water phase), we will clarify some of the key nanoparticle properties in different environments and establish much needed guidelines for designing nanoparticles for a given application.