Strain Stiffening and Negative Normal Force of Agarose Hydrogels.

ABSTRACT: Inspired by the specific strain stiffening and negative normal force phenomena in several biological networks, herein, we show strain stiffening and negative normal force in agarose hydrogels. We use both pre-strain and strain amplitude sweep protocols in dynamic rheological measurements where the gel slip was suppressed by the in situ gelation in the cross-hatched parallel plate rheometer geometry. Within the stiffening region, we show the scaling relation for the differential modulus K ∝ σ¹, where σ is stress. The strain at the onset of stiffening is almost constant throughout the concentration range. The gels show negative apparent normal stress difference when sheared as a result of the gel contraction. The pore size of the hydrogel is large enough to allow wat

SUBMITTER: Martikainen L 

PROVIDER: S-EPMC7690039 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature