Thermoresponsive stiffening with microgel particles in a semiflexible fibrin network

Abstract

We report temperature-responsive soft composites of semiflexible biopolymer networks (fibrin) containing dispersed microgel colloidal particles of poly(N-isopropylacrylamide) (pNIPAM) that undergo a thermodynamically driven de-swelling transition above a Lower Critical Solution Temperature (LCST). Unlike standard polymer-particle composites, decreasing the inclusion volume of the particles (by increasing temperature)is concomitant with a striking increase of the overall elastic stiffness of the composite. We observe such a behavior over a wide composition space. The composite elastic shear modulus reversibly stiffens by up to 10-fold over a small change in temperature from 25-35°C. In isolation, the fibrin network and microgel suspension both soften with increased temperature, making the stiffening of the composites particularly significant. We hypothesize that stiffening is caused by contracting microgel particles adsorbing on the fibrin filaments and modifying the structure of the semiflexible network. We develop two phenomenological models that quantify this hypothesis in physically distinct manners, and the derived predictions are qualitatively consistent with our experimental data

arXiv comment35 pages, 14 figures

References in corpus (7)

• Elasticity of Semiflexible Biopolymer Networks
• Yield Stress Materials in Soft Condensed Matter
• Modeling semiflexible polymer networks
• The origin of stiffening in cross-linked semiflexible networks
• Radial distribution function of semiflexible polymers
• Nonlinear elasticity of semiflexible filament networks
• Linear and Nonlinear Rheology and Structural Relaxation in Dense Glassy and Jammed Soft Repulsive Microgel Suspensions

Cited by in corpus (2)

• Strain-controlled critical slowing down in the rheology of disordered networks
• Criticality enhances the reinforcement of disordered networks by rigid inclusions