Extreme thermodynamics with polymer gel tori: Harnessing thermodynamic instabilities to induce large-scale deformations. Academic Article uri icon

abstract

  • When a swollen, thermoresponsive polymer gel is heated in a solvent bath, it expels solvent and deswells. When this heating is slow, deswelling proceeds homogeneously, as observed in a toroid-shaped gel that changes volume while maintaining its toroidal shape. By contrast, if the gel is heated quickly, an impermeable layer of collapsed polymer forms and traps solvent within the gel, arresting the volume change. The ensuing evolution of the gel then happens at fixed volume, leading to phase separation and the development of inhomogeneous stress that deforms the toroidal shape. We observe that this stress can cause the torus to buckle out of the plane, via a mechanism analogous to the bending of bimetallic strips upon heating. Our results demonstrate that thermodynamic instabilities, i.e., phase transitions, can be used to actuate mechanical deformation in an extreme thermodynamics of materials.

published proceedings

  • Phys Rev E

altmetric score

  • 6.25

author list (cited authors)

  • Chang, Y., Dimitriyev, M. S., Souslov, A., Nikolov, S. V., Marquez, S. M., Alexeev, A., Goldbart, P. M., & Fernndez-Nieves, A.

citation count

  • 12

complete list of authors

  • Chang, Ya-Wen||Dimitriyev, Michael S||Souslov, Anton||Nikolov, Svetoslav V||Marquez, Samantha M||Alexeev, Alexander||Goldbart, Paul M||Fernández-Nieves, Alberto

publication date

  • August 2018