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Confinement Effects On Polymer Nucleation And Crystallization: From Droplets To Alumina Nanopores

Abstract:

We review how confinement from the micron to the nanometer scale can affect nucleation and crystallization of polymers in: droplets, blends, block copolymers and infiltration into alumina nanopores. Confinement can produce fractionated crystallization or exclusive crystallization at much higher supercoolings as compared to bulk polymers, as the degree of confinement increases. For highly confined heterogeneity free micro or nano-domains, overall crystallization kinetics is dominated by nucleation and therefore becomes first order. The nucleation mechanism changes from heterogeneous nucleation for bulk polymers to surface or homogeneous nucleation for ensembles of confined and isolated heterogeneity free micro or nanodomains. Surface nucleation is more commonly found than homogenous nucleation, although this fact is not frequently recognized in the literature.