A comparative study of nanoconfinement effects on polymer chain dynamics

We report on a study of the effects of nanoconfinement on polymer chain dynamics within the framework developed by Muthukumar [Muthukumar, M. (1991). Journal of Non-Crystalline Solids, 131, 654-666.], who suggests that there is an entropically controlled dynamical regime between the Rouse and the reptation regimes that affects the power law dependence on molecular weight of the transport properties. We have reanalyzed and compared various data from the literature for both unentangled [Hor, J. L.et al. (2018). Macromolecules, 51(14), 5069-5078..] and entangled [Shin, K., et al., Nature materials. (2007), 6(12), 961-965.] [Lange, F., et al. (2015). ACS Macro letters, 4(5), 561-565.] polymers. We find that as the confinement of the unentangled polymers becomes extreme, the chain dynamics change from those of a Rouse-like regime to those of an entropic barrier regime. For entangled polymers, the chain dynamics change from those of a reptation-like regime to those of an entropic barrier regime as polymers become increasingly confined, consistent with the Muthukumar postulate.