Institut Charles Sadron Event

Horaire: 16H00 Abstract: Complexation of oppositely charged polyelectrolytes plays a fundamental role in the compartmentalization of the living cells. It is also important for technological and pharmaceutical applications; for example, coacervates are used as underwater adhesives, and self-assembled structures on their basis are promising for hydrophilic ionic drug and gene delivery. In my talk, I’ll highlight our recent achievements in the theoretical treatment of polyelectrolyte complex coacervation, which not only provide a rationalization for experimental studies and are confirmed by computer simulations but also possess predictive capabilities. The starting point is the “usual” symmetric coacervate of flexible polyelectrolytes, whose equilibrium properties, such as density, correlation length, and surface tension, are predicted in a wide range of solvent qualities and salt concentrations. Then I’ll consider more specific effects of (i) polyelectrolyte stiffness leading to liquid crystalline ordering within the coacervate, (ii) incompatibility between polyanions and polycations due to non-Coulomb interactions triggering intra-coacervate microphase separation, and (iii) primary sequence of charged and uncharged units in polyions enabling tunability of the coacervate stability region. Finally, I’ll discuss equilibrium properties of complex coacervate core micelles and salt-induced changes of their morphology.