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Direct observation of prefreezing at the interface melt-solid in polymer crystallization.

ABSTRACT: Crystallization is almost always initiated at an interface to a solid. This observation is classically explained by the assumption of a reduced barrier for crystal nucleation at the interface. However, an interface can also induce crystallization by prefreezing (i.e., the formation of a crystalline layer that is already stable above the bulk melting temperature). We present an atomic force microscopy (AFM)-based in situ observation of a prefreezing process at the interface of a polymeric model system and a crystalline solid. Explicitly, we show an interfacial ordered layer that forms well above the bulk melting temperature with thickness that increases on approaching melt-solid coexistence. Below the melting temperature, the ordered layer initiates crystal growth into the bulk, leading to an oriented, homogeneous semicrystalline structure.

SUBMITTER: Lohmann AK

PROVIDER: S-EPMC4267372 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature

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Direct observation of prefreezing at the interface melt-solid in polymer crystallization.

Löhmann Ann-Kristin AK Henze Thomas T Thurn-Albrecht Thomas T

Proceedings of the National Academy of Sciences of the United States of America 20141124 49

Crystallization is almost always initiated at an interface to a solid. This observation is classically explained by the assumption of a reduced barrier for crystal nucleation at the interface. However, an interface can also induce crystallization by prefreezing (i.e., the formation of a crystalline layer that is already stable above the bulk melting temperature). We present an atomic force microscopy (AFM)-based in situ observation of a prefreezing process at the interface of a polymeric model s ...[more]

PMID: 25422447

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