Résumé:

The self-assembled transient networks constitute a class of complex materials forming spontaneously 3D networks at thermodynamical equilibrium, that can transmit transiently elastic stresses over macroscopic distances. These physical gels are generally formed of a network of polymer chains reversibly linked in a solvent. The transient nature of the junctions allow them, contrary to cross-linked networks, to relax the constraints by dissociation an reformation of the junctions: so they are able for instance to self-repair after dammage. Because of their spectacular viscoelastic properties, these materials have many applications . From the experimental results obtained with an experimental model this lecture will consider successively some general interesting physical properties for this class of of systems:(i) the pair potential induced by two beads reversibly linked by telechelic polymers, (ii), the phase behavior of the gels, (iii) the linear viscoelastic properties, and (iv) the nucleation and propagation of a fracture in this complex fuid.