Soft matter under osmotic stress

In this article, we will show that the osmotic stress method can be successfully applied to study the thermodynamics of self-assembly phenomena in soft matter systems, such as biopolymer liquid crystals, surfactant and lipid mesophases, and polyelectrolyte-surfactant complexes. We will give two examples to that effect. Firstly, we will present intercolumnar force measurements between cylindrical surfactant micelles in solid-state polyelectrolyte-surfactant complexes as a function of ionic strength. Secondly, we will present measurements of the DNA cholesteric spherulite structure and pitch as a function of osmotic pressure in an effort to evaluate the chiral contribution to the interaction between DNA molecules.