Nanorheology

Inter-diffusion of polymers

Weakly acidic polymers can be selectively released and reabsorbed from polyacid films upon changing solution pH values. Similar polymer diffusion phenomenon may occur in various polymeric systems such as polymer melts, solutions, and oppositely charged polyelectrolyte gels. We investigate the inter-diffusion mechanism and the dependence of release time on molecular parameters.

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1. "pH-Induced Release of Polyions from Multilayer Films" by E. Kharlampieva, J. F. Ankner, M. Rubinstein, and S. Sukhishvili, Physical Review Letters 100, 128303 (2008).

 

Motion of a particle through polymer

Micro-rheological experiments detect the movement of a particle through polymeric systems and thus provide a direct way to probe local polymer dynamics. We study sub-diffusive motion of probe particles and coupling between particle and polymer dynamics in melts, solutions, and gels analytically and numerically.

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