Dr Peter Yatsyshin
PhD Chemical Engineering, Imperial College London, UK (advisor: Serafim Kalliadasis); MS Quantum Mechanics, Saint-Petersburg State University, Russia
I am currently a research associate in the Complex Multiscale Systems group in the Department of Chemical Engineering at Imperial College London, where I did my PhD under the supervision of Professor Serafim Kalliadasis.
My research focuses on the nano-scale description of various equilibrium and dynamic capillary phenomena in inhomogeneous fluids.
For microscopic fluid systems, the concepts of surface tensions, contact angles and pressure differences across curved menisci forming the basis of macroscopic descriptions, traceable back to the works of Young and Laplace, become quite limited. One must explicitly take into account the underlying molecular structure of the fluid, since most of the non-trivial effects are caused by the interplay of different length scales, such as the ranges of fluid-fluid and wall-fluid potentials or the characteristic dimensions of the confining geometry. These parameters often act as independent thermodynamic fields, leading, according to the Gibbs' phase rule, to a strikingly rich phase behaviour. The standard theoretical approaches to phase transitions in inhomogeneous fluids are mean field van der Waals loops and renormalization group theory. While the latter approach is quite abstract and is usually applied to obtain the critical exponents pertinent to phase transition, the former one is usually based on assumptions about the nature and character of the forces acting in the system and thus is quite specific.
My recent work involves using the computational apparatus of the classical Density Functional Theory (DFT) for parametric studies of wetting in nanopores. DFT is a statistical mechanical framework which allows one to obtain detailed information about the structure of the fluid in contact with a surface by making quite straightforward and general assumptions about the character of molecular interactions. It does not assume the existence of interfaces, obtaining them as output, along with contact angles, menisci shapes, and even complete phase diagrams.
Understanding of capillary wetting phenomena is important for fundamental science since it provides one of the most striking manifestations of the attractive intermolecular forces. From the applied point of view, investigations of phase behaviour in mesoscopically confined inhomogeneous fluids are essential for building nano-reactors, filtering and purification, the design of "lab-on-chip" devices with tunable wetting properties.