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纳米技术的核心问题：从设计和预测在生命系统中安全有效地使用NPs，到形成可拉伸或自修复的薄膜和复合材料，再到将纳米粒子组装成下一代太阳能电池、led和其他应用的上层结构。纳米颗粒呈现出一个复杂的界面，通过它它们可以与环境相互作用，这种复杂性源于各种可能的NP核形状和大小，这些形状和大小反过来又定义了纳米颗粒涂层的可用表面化学和物理性质。在各种各样的合成纳米粒子系统中，硫醇覆盖的金纳米粒子是研究最彻底的。尽管如此，关于NPs在不同环境条件下的表现，仍然存在许多基本问题(例如，什么使“好溶剂”好？这如何影响NPs与生物膜的相互作用？这些问题是先前在这些体系中观察到的物理性质（溶解度和自组装）中经常观察到的反直觉趋势的核心。***该研究项目将提高我们对模型纳米颗粒系统的物理性质（混合）的理解，该系统由不同金核尺寸和硫醇覆盖层密度的球形硫醇覆盖金纳米颗粒组成。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，对油相或水相的溶剂化亲和力），我们将澄清不同环境下纳米颗粒的一些关键性质，并为特定应用设计纳米颗粒建立急需的指导方针。

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.