Hehe, I think a lot of people attribute to physics what I attribute to chemistry. Put simply, I (slightly jokingly) say that “chemistry is when there’s too many electrons for the physicists” ;)

I work in a junction of several fields: One side is in developing equations of state, which means we develop models that tell you everything from how compressible a fluid is, to how much heat it releases when condenses, to what the equilibrium state is (liquid, vapour, several immiscible liquids, etc.), or how the density changes with temperature and pressure, etc. These models primarily apply to bulk fluids at equilibrium. The primary framework we work in here is called “statistical associating fluid theory (SAFT)”.

Another side is what’s called “interfacial thermodynamics”, which involves looking at how liquid-liquid, liquid-vapour, and fluid-solid interfaces behave. Here we develop models for predicting how surface tension changes under different conditions, the nucleation energy of bubbles and droplets, and how various species “adsorb” on different surfaces/interfaces. The major framework we’re working in here is called “classical density functional theory”, which is quite similar to the more “commonly” known “quantum (or electron) density functional theory”.

Then there’s irreversible thermodynamics, which is a framework linking local thermodynamic properties (temperature, pressure, chemical potential, etc.) outside equilibrium to transport rates. This lets us model stuff like evaporation rates, ion transfer in batteries, and much more. Essentially, if you have transport processes with more than one driving force (e.g. a battery, where you have simultaneous gradients in temperature, electrical potential, and chemical potential), you need irreversible thermodynamics to make accurate transport models, because Fouriers law, Ficks law, Ohms law, etc. don’t really apply anymore.

Finally, I’ve done quite a bit of work on transport theory. Specifically, I’ve worked on developing predictive models for the transport properties (viscosity, thermal conductivity, diffusion coefficients, etc.) of fluids at moderate-high pressures. The major framework here is kinetic gas theory, more specifically revised Enskog theory.

This became quite a list, but yeah… that’s what I do :) let me know if you would like some follow-up reading recommendations or more details:)