Theory and simulation of soft condensed matter

点击翻译按钮获取中文摘要

Soft condensed matter encompasses a diverse range of materials, including liquids, glasses, gels, colloids, and granular materials, that appear ubiquitously throughout nature, and in engineered materials and devices. For example, liquids represent one of the main forms of matter, but their disordered structure and complex molecular motions have made them difficult to understand. When a liquid is cooled rapidly, it can become trapped in an amorphous glass which has the structure of a liquid but the mechanical rigidity of a solid. When cooled slowly, that same liquid can freeze to a crystal, with long range periodic order. In some cases, these crystals have large, complex unit cells that require structural organization over many length scales. The molecular processes leading to vitrification and nucleation are still unknown. Colloids and even macroscopic, athermal, granular materials, such as sand, exhibit the similar types of complex particle motion and phase behaviour as liquids, suggesting there are important underlying principles that connect these seemingly disparate forms of matter. This proposal describes a research program that investigates the structural, thermodynamic and dynamic properties of soft condensed matter systems and aims to address these fundamental questions using molecular theory and computer simulation. In particular, we are focused on understanding how the ability of particles to pack together influences the thermodynamics and dynamics of the liquids. We aim to study how these change when the systems become confined. This will give us insight into how glasses are formed and what factors affect their properties. It will also help us to understand how fluids move in confined systems such as carbon nanotubes and zeolites. We are also interested in nucleation phenomena and plan to develop rigorous theoretical methods for calculating nucleation rates for a range of systems, including the nucleation of complex crystals and nucleation in atmospheric aerosols. While the main focus of the work in this proposal is fundamental in nature, we are using the knowledge gained through our research to explore important applications in technology and nature. For example, we are using our knowledge of the way particles move in confined environments and single file diffusion to develop nanofluidic devices for the separation of mixtures. Also, our studies of nucleation will be used to develop and test accurate theories for the prediction of particle growth and nucleation in atmospheric aerosols, so they can be used in cloud and atmospheric modelling.