Liquid-State and Soft-Matter Physics

The course aims at teaching the fundamentals of the theory of equilibrium properties of classical liquids such as fluids of neutral and charged particles, polymer solutions, and colloidal dispersions. Starting from a basic knowledge of statistical mechanics, we will first consider the mean-field approximation for interacting particles, and subsequently the density-density correlation function together with some approximate methods for determining it. We will then introduce the concept of effective interaction, which will be applied in several cases involving polymer solutions, stabilization of colloidal dispersions, and osmotic depletion forces.

Students who attend the course will develop the following skills:

1) They will be able to establish the link between the microscopic interaction and the macroscopic properties of the fluid in some paradigmatic cases, and to grasp the similarities as well as the differences between them.

2) They will be able to use the mean-field approximation and to understand its limitations.

3) They will learn some approximate methods for determining the correlation functions, and those for determining the thermodynamics from the correlations.

4) They will get familiar with the simplest equations of state for uncharged and charged fluids and polymer solutions and with the qualitative features of their phase diagrams.

5) They will learn the basic features of colloidal dispersions, including electrostatic and steric stabilization.

6) They will acquire knowledge about the origin and the description of osmotic depletion forces by examining in detail a specific model of a colloid-polymer mixture.