title: Fracture and adhesion of soft materials: a review.
abstract: Soft materials are materials with a low shear modulus relative to their bulk modulus and where elastic restoring forces are mainly of entropic origin. A sparse population of strong bonds connects molecules together and prevents macroscopic flow. In this review we discuss the current state of the art on how these soft materials break and detach from solid surfaces. We focus on how stresses and strains are localized near the fracture plane and how elastic energy can flow from the bulk of the material to the crack tip. Adhesion of pressure-sensitive-adhesives, fracture of gels and rubbers are specifically addressed and the key concepts are pointed out. We define the important length scales in the problem and in particular the elasto-adhesive length Γ/E where Γ is the fracture energy and E is the elastic modulus, and how the ratio between sample size and Γ/E controls the fracture mechanisms. Theoretical concepts bridging solid mechanics and polymer physics are rationalized and illustrated by micromechanical experiments and mechanisms of fracture are described in detail. Open questions and emerging concepts are discussed at the end of the review.
authors.affiliation: Sciences et lngénierie de la Matière Molle, CNRS UMR 7615, École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI), ParisTech, PSL Research Univeristy, 10 rue Vauquelin, F-75231 Paris cedex 05, France. SIMM, UPMC Univ Paris 06, Sorbonne-Universités, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Costantino
authors.initials: C
authors.lastname: Creton
authors.forename: Matteo
authors.initials: M
authors.lastname: Ciccotti