Dynamics of polymer melts confined between adsorbing surfaces spaced at molecular dimensions
New physics emerges when polyphenylmethylsiloxane (PPMS) adsorbed between mica surfaces spaced at molecular dimensions undergoes oscillatory shear. The polymers experience a dynamic liquid-like to rubber-like transition at the onset of long range surface forces $(\sim$4.5 R$\sb{\rm G}).$ The long time relaxations of the polymers are effectively frustrated at the start of the strong repulsive short range surface forces (hard-wall $\sim$2.8 R$\sb{\rm G}).$ The static surface forces and dynamic regimes scale with the size of the polymer molecules. This reflects the universal ranges of polymer melts perturbed by the adsorbing surfaces.
Chemistry, Polymer, Engineering, Chemical, Engineering, Materials Science
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign