Electrostatic interactions are a common and important form of interaction in soft matter. In this paper Bum Jun Park, Jan Vermant and Eric M. Furst measure the interactions between colloids at a decane-water interface using optical tweezers. The team also used Monte Carlo simulations to understand the effect of heterogeneity on the equilibrium suspension structure.
The electrostatic repulsive force has the expected dependence on particle separation for a dipole–dipole interaction but exhibits a distribution of magnitudes in which the force depends on the particle pairs tested and sample preparation method.
Read the full article here: Bum Jun Park, Jan Vermant and Eric M. Furst, Soft Matter, 2010, DOI:10.1039/C0SM00485E