Département de chimie moléculaire

The authors report a self-assembled metallo suprapolymer gel exhibiting remarkable self-healing features. The Ni2BTC metallo suprapolymer gels result from the complexation of Ni2+ metal ions by a tritopic ligand (bis-terpyridine cyclam) in DMF and an annealing step at 50° for 24 h. The self-healing properties were characterized by visual inspection, rheol. and impedance spectroscopy measurements: the results are compared with those of a fatty acid-based mol. organogel chosen as a ref. system. The creep-recovery anal. uses the Burgers model for low strains and characterizes a recovery capability of up to 72{%} of the deformation in Ni2BTC gels while it is only 32{%} for the fatty acid organogel. At very large strains, the impedance spectroscopy confirms the slow repairing process consistently with the visual observations. Rheol. measurements demonstrate the restructuring of the fractured networks. The fatigue of the self-healed gel networks undergoing long sequences of strain-relaxation steps was characterized. [on SciFinder(R)]