Structure and thermodynamics of associating rods solutions

TL;DR

This study combines computer simulations and mean field models to analyze the thermodynamics and structure of associating rod-like polymers, revealing insights into sol-gel transitions, precipitation, and orientational order.

Contribution

It provides a combined simulation and analytical approach to understand the thermodynamics of associating rods, highlighting the effects of associating groups on phase transitions.

Findings

Sol-gel transition aligns with divergence of cluster size.

Heat capacity peaks at precipitation transition.

Gelation is insensitive to associating group distribution.

Abstract

Thermoreversible sol-gel transitions in solutions of rod-like associating polymers are analyzed by computer simulations and by mean field models. The sol-gel transition is determined by the divergence of the cluster weight average. The analytically determined sol-gel transition is in good agreement with the simulation results. At low temperatures we observe a peak in the heat capacity, which maximum is associated with the precipitation transition. The gelation transition is sensitive to the number of associating groups per rod but nearly insensitive to the spatial distribution of associating groups around the rod. The precipitation is strongly dependent on both the number and distribution of associating groups per rod. We find negligible nematic orientational order at the gelation and precipitation transitions.