MPhys Thesis
My Master of Physics degree included a year-long research project in computational condensed matter physics. Titled Molecular Dynamics Simulations of 2D-Confined Water, the projected aimed to develop theoretical support for the experimental work of Fumagalli et al. (2018) published in Science. This thesis work was composed of two reports:
Graphene and other two-dimensional (2D) crystals have recently shown the unprecedented ability of confining molecular liquids in nanochannels, opening up new avenues for exploring the properties of confined molecules such as water, which are different than in bulk. The recent discovery that water confined between 2D crystals has an anomolously low dielectric constant is one such example [1]. This discovery has major implications in many disciplines as the dielectric constant of water directly affects various forces between micro-objects and macromolecules. In turn, these forces define many phenomena in the world around us; including surface hydration, ion and molecular solubility, molecular structuring and reactions. This research project aimed to assist new experiments on the dielectric properties of confined water being carried out at the National Graphene Institute. It did so by investigating the structure of water (ordering, molecular orientation) at the interface with solid surfaces, and when confined between 2D atomically thin slits. This as done using molecular dynamics simulations (MD), a method widely used in a variety of fields, from physics and chemistry to biology, which consists of numerically modelling the trajectories of single atoms composing the system [2]. The link between atomic trajectories and the properties of the system is then made by statistical physics.
The work involved running molecular dynamics simulations using MD softwares, writing programs to analyze the obtained trajectories, and subsequently applying them to the case of confined water. Simulations were run both locally and remotely.
N.B. Due to constraints caused by the Covid-19 pandemic, planned experimental lab work at the Institute was unfortunately not viable. These experiments had intended to measure properties of confined water using advanced atomic force microscopy techniques. As a result, aspects of the computational work were extended in the second half of this project.
[1] L.Fumagalli, A. Esfandiar, R. Fabregas, S. Hu, P. Ares, A. Janardanan, Q. Yang, B. Radha, T. Taniguchi, K. Watanabe, G. Gomila, K.S. Novoselov, A.K. Geim. Anomalously low dielectric constant of confined water. Science, 360, 1339 (2018).
[2] D. Frenkel and B. Smit. Understanding molecular simulation: from algorithms to applications, Vol.1, Elsevier, 2001
Additional projects
- Measuring cross sections of Z boson decays with the ATLAS detector at the LHC
- Investigating the Hall Effect in Indium Antimonide
- Investigating road traffic flows using stochastic automaton models