The effect of temperature jumps during polymer crystallization

TL;DR

This study investigates how temperature jumps influence polymer crystal surface steps, using simulations to determine if these features reveal underlying crystallization mechanisms, with implications for experimental interpretation.

Contribution

The paper demonstrates through simulations that step profiles can indicate fixed-point attractors in polymer crystallization, but are also affected by other factors like edge rounding and fluctuations.

Findings

Step profiles can reveal fixed-point attractors in the model.

Temperature decreases cause edge rounding effects.

Temperature increases reflect crystal thickness fluctuations.

Abstract

Temperature changes during the growth of lamellar polymer crystals give rise to steps on the surface of the crystals. It has recently been suggested that these steps could provide important insights into the mechanism of polymer crystallization. In particular, a characterization of the profiles of these steps might reveal the fixed-point attractor that underlies a recently proposed crystallization mechanism. Here we examine this hypothesis by performing simulations of such temperature jumps using the Sadler-Gilmer model. We find that for this model the step profiles do reveal the fixed-point attractor. However, for temperature decreases they also reflect the rounding of the crystal edge that occurs in this model and for temperature increases they also reflect the fluctuations in the thickness present in the crystal. We discuss the implications of these results for the interpretation of experimental step profiles.