Strong through to weak 'sheared' gels

Abstract

The gelation of an agar biopolymer solution under quiescent conditions enables the formation of a strong network structure capable of sustaining mechanical deformation up to a critical strain or stress above which it fractures. Gelation of the same solution under shear conditions results in a weak gel which is capable of sustaining mechanical deformation at small strain or stresses but which flows if subjected to higher deformations. The purpose of this study is to investigate how shear can alter so drastically the rheological properties of biopolymer gels. We achieve this by investigating the nonisothermal gelation behaviour of agar biopolymer gels prepared under both oscillatory and steady..