Study of the Formation of Crystalline Phases for Non-Convex Hard Particles through Monte Carlo Simulations

• Grant number: 24/07598-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: December 09, 2024
• End date: June 08, 2025
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Luís Fernando Mercier Franco
• Grantee: Nathan Barros de Souza
• Supervisor: Carlos Avendano Jimenez
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of Manchester, England
• Associated to the scholarship: 21/10648-4 - New equation of state for mixtures of nonspherical molecules based on statistical mechanics, BP.DR

Abstract

Understanding the formation of crystalline phases is essential for the design of advanced functional materials for industrial applications. Crystals possess ordered arrangements of atoms, molecules, ions, or even nanostructures such as colloidal particles, exhibiting unique anisotropic properties. While crystallography is a commonly experimental technique to determine crystal structures, molecular simulations provide insights into solid dynamics and thermodynamics. Moreover, molecular simulations can be used to explore the formation of crystals that have not been observed experimentally and can be used for the design of new materials. The so-called floppy-box Monte Carlo (FBMC) method is a powerful technique to determine crystal candidates but is unable to indicate what structure is thermodynamically more stable. For this purpose, the Einstein crystal method developed by Frenkel and Ladd (FL) can be used to find the absolute free energy of crystal candidates using thermodynamic integration. When combined, experimental techniques and simulations enhance the understanding of crystalline materials, enabling the synthesis of materials with tailored properties for various fields. This study will focus on non-convex hard particles forming crystalline structures resembling those of fullerene microcrystals ($C_{60}$ and $C_{70}$) obtained via co-precipitation of fullerene-methylbenzene solutions in 2-propanol. These particles hold promise as photonic crystals in diverse applications, including the manipulation/transmission of electromagnetic waves, light reception/emission, and chromatic sensing. In this work, the aim is to predict and validate the crystalline structure of fullerene microcrystals using the FBMC and the FL methods, respectively. Additionally, the fluid-solid phase equilibrium of these substances will also be studied through molecular simulation.