Confinement-induced fluid-gel transition in polymeric solutions

Abstract

The viscoelastic properties of confined polymer solutions are probed by particle-tracking microrheology. The mean squared displacement of spherical probe particles embedded in the solution and the storage and loss moduli of the system are measured as the level of confinement is increased. It is found that those quantities change continuously as the confinement increases, and, at severe conditions, when the constrain reaches the size of the polymer molecule, the system undergoes a transition from a viscoelastic fluid to a gel.