Nanoscale self-assembly in confined geometries

近年来，纳米材料的研究进展迅速。这些新材料的一个例子是由纳米颗粒（如富勒烯）组成的，这些纳米颗粒被限制在纳米管中，并且在这些系统中观察到有序相。这种自定序现象可能是其独特的电学和光学特性的关键，目前正被用于生物医学应用和传感器技术。为了促进这些纳米材料的发展并实现其商业潜力，我们需要更好地了解它们的相行为。本研究的主要目标是：(i)发展对带电约束下纳米级自组装的基本理解，以及（ii）探索这些系统的新应用，特别是在环境工程方面。蒙特卡罗和分子动力学模拟将用于研究(i)约束几何形状、粒子尺寸和电荷不对称性等各种参数对约束粒子结构性质的影响，以及（ii）表面活性剂在约束中的自组装。此外，密度泛函理论将应用于分析粒子间和粒子约束相互作用。本实验将采用砂填充柱研究有机微粒的胶束增溶和表面活性剂在多孔介质中的吸附，并系统研究表面活性剂分子结构和溶液条件的影响。本研究还将探索亚微米颗粒在有机污染物固化/稳定中的应用。特别是，我们将通过测量污染物浸出率来研究这些颗粒在水泥基质中作为有机吸附剂的功效。这项研究的结果有望有助于我们对受限纳米颗粒和表面活性剂溶液的基本理解，特别是它们的自组装行为。更重要的是，这些系统的知识将被证明对纳米材料的研究和发展是有价值的。此外，对密闭纳米颗粒的研究也有助于我们了解它们对环境的影响，这在近年来已成为一个日益关注的问题。

The development of nanomaterials have been progressing rapidly in recent years. An example of these new materials consists of nanoparticles such as fullerene confined in a nanotube, and ordered phases have been observed in these systems.  Such self-ordering phenomena may be key to their unique electrical and optical properties, which are now being exploited in biomedical applications and sensor technologies.  To facilitate the development of these nanomaterials and to realize their commercial potential, we need a better knowledge of their phase behaviour. The primary objectives of this research are (i) to develop a fundamental understanding of nanoscale self-assembly in charged confinements, and (ii) to explore novel applications of these systems, particularly in environmental engineering.  Monte Carlo and molecular dynamics simulation will be used to study (i) the effects of various parameters, such as confinement geometry and particle size and charge asymmetry, on the structural properties of confined particles, and (ii) surfactant self-assembly in confinement.  In addition, density functional theory will be applied to analyze interparticle and particle-confinement interactions.  In the proposed experimental program, micellar solubilization of organics and surfactant adsorption in porous media will be studied using a sand-packed column, and a systematic study of the effects of surfactant molecular structure and solution conditions will also be conducted. This research will also explore the use of submicron particles in the solidification/stabilization of organic contaminants. In particular, we will study the efficacy of these particles as an organics adsorbent in cement matrices by measuring the contaminant leaching rate.  The results of this research are expected to contribute to our fundamental understanding of confined nanoparticles and surfactant solutions, particularly their self-assembling behaviour.  More importantly, the enhanced knowledge of these systems will prove to be valuable to nanomaterial research and development. In addition, the study of confined nanoparticles would also contribute to our knowledge of their environmental impact, which has become a growing concern in recent years.