Magnetodeformation of ferrogels and ferroelastomers. Effect of microstructure of the particles' spatial disposition

The work deals with the theoretical study of ferrogel/ferroelastomer deformations under the action of a homogeneous magnetic field. The compositions with linearly magnetizable non-Brownian particles are considered. Under the field action the ferrogel/ferroelastomer samples can either elongate or contract in the field direction. The type of deformation is determined by the sample shape and microstructure of the particles' spatial disposition. Two kinds of systems are studied. The first one is the composition with the particles homogeneously distributed, like in an ideal gas, in the polymer matrix. The second kind is the system of linear chain-like aggregates of densely situated particles. The results show that the particles' spatial disposition in the matrix is crucially important for the type of macroscopical deformation of the magnetopolymer compositions. The systems with the gas-like distribution of particles, depending on the sample shape, can either elongate or contract, whereas the chains stimulate the sample elongation.