Abstract

Co-Authors: Costantino Creton, Cornelis Storm, Wouter Ellenbroek

Entropy is the daunting “second half” of thermodynamics, universally encountered yet often overlooked when designing molecular recipes for new soft materials and structures. This talk seeks to inspire a line of thought on how entropy can be harnessed as a central design element in soft polymeric materials, for imbuing adaptability, robustness, and functional uniqueness.

Highly elastic yet failure-resistant polymer gels with reversible crosslinks [1] will be showcased as a recent example where entropy provides unexpected functionality. Using a combination of theory, molecular simulation, and polymer self-consistent field theory for networks [2], I will discuss how entropy counter-intuitively leads to spatial clustering of reversible crosslinks around permanent crosslinks in the polymer gel. This entropy-induced order leads the gel to be less prone to failure, while maintaining its high degree of extensibility [3]. Practical guidelines will be outlined to optimise this design in experiment, along with a discussion of key kinetic and timescale considerations.

[1] Kean, Z. S.; et al. Adv. Mat. 2014, 26, 6013.
[2] Tito, N. B.; Storm, C.; Ellenbroek, W. G. Macromolecules 2017, 50, 9788.
[3] Tito, N. B.; Creton, C.; Storm, C; Ellenbroek, W. G. Soft Matter 2019, 15, 2190.