Polysoaps: Extension and compression

Intramolecular self-assembly in polysoaps qualitatively modifies their deformation behavior. The modified elasticity reflects the coupling of the chain deformation to the internal degrees of freedom associated with the existence of intrachain micelles. The equilibration of this secondary structure tends to lower the restoring force associated with the deformation in accordance with the LeChatelier principle. The force larva for extension and for confinement into a slit are derived for the case of a linear string of spherical intrachain micelles. In both situations the chain behaves as a string of stars for weak deformations. Force laws characteristic of simple linear chains are obtained for strong deformations. Novel force laws, reflecting strong coupling to the secondary structural are obtained at the intermediate regime. For intermediate extensions, the tension in the chain, f, is independent of R, the end to end distance, up to logarithmic corrections, i.e., f similar to R-0 In g(R), where g(R) is a slowly increasing function of R. For intermediate confinement f similar to D-28/23, where D is the spacing between the two nonadsorbing walls.