On the Deformation Behaviour of Collapsed Polymers

A scaling analysis of the deformation behaviour of a collapsed linear coil in a poor solvent is presented. The elastic response of an ideal coil is found for strong deformations. The response to weaker deformations is dominated by the surface free energy: for weak deformations linear response is expected. Intermediate deformations result in nonlinear response. In particular, the restoring force, f , for intermediate stretching scales as f ∼ L 0 and as f ∼ L -2 for compression, where L is the globule size along the direction of the force. The novel f ∼ L 0 regime is reminiscent of a first-order phase transition from a collapsed globule to stretched coil.