| A ferrogel model based on a polymer network with single-domain magnetic particles is constructed. The non-magnetic matrix is represented by a two-dimensional bead-spring model where beads interacting via Lennard-Jones potential are connected by harmonic springs. It is assumed that in each polymer chain of beads some bonds include magnetic grains. In the considered model, a conformation of polymer chains is analyzed in terms of bead positions and magnetic grains are introduced into the model via magnetic torque acting on the bond connecting neighboring beads. The magnetic torque is absent if the external magnetic field is set to zero. We examine the case when the polymer matrix under consideration exhibits unusual auxetic behavior, i.e., it expands under a stretching force applied to the ends of the chain. The analysis of the ferrogel model presented in this paper is a result of molecular simulations in which the motion of grain magnetization is described by the Landau-Lifshits-Gilbert equation. |
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