Swollen-to-globular transition of a self-avoiding polymer confined in a soft tube

Monte Carlo simulations are presented for the structural transition of a self-avoiding polymer confined in an elastic soft tube, within the Helfrich energy model for the description of a fluctuating surface. Based on the simulation data of the maximum extension of the confined polymer in the tube and of the tube radius, a swollen-to-globular transition is identified where the confined polymer undergoes an abrupt transition from a shape elongated along the tube axis to a globule that is of much smaller dimensions than that of an unperturbed polymer. An extended regime in the parameter space has been explored where various scaling properties can be viewed.