Extension of rod-coil multiblock copolymers and the effect of the helix-coil transition
The extension elasticity of rod-coil mutliblock copolymers is analyzed for two experimentally accessible situations. In the quenched case, when the architecture is fixed by the synthesis, the force law is distinguished by a sharp change in the slope. In the annealed case, where interconversion between rod and coil states is possible, the resulting force law is sigmoid with a pronounced plateau. This last case is realized, for example, when homopolypeptides capable of undergoing a helix-coil transition are extended from a coil state.
Buhot
A
UMR 5819 (CEA, CNRS, UJF), DRFMC/SI3M, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France.
Halperin
A