Motion of ferroparticles inside the polymeric matrix in magnetoactive elastomers

Abstract

Ferroelastic composites are smart materials with unique properties including large magnetodeformational effects, strong field enhancement of the elastic modulus and magnetic shape memory. On the basis of mechanical tests, direct microscopy observations and magnetic measurements we conclude that all these effects are caused by reversible motion of the magnetic particles inside the polymeric matrix in response to an applied field. The basic points of a model accounting for particle structuring in a magnetoactive elastomer under an external field are presented.

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

“…[20] demonstrate that the chain-like aggregates of closely situated particles stimulate elongation of the ferrogels in the field direction. Therefore the results of experiments [16,22] and computer simulations [16,20,22] are in agreement with the conclusion of the presented model.…”

“…However in experiments, where the chains of the densely situated particles took place, only elongation of the samples has been detected [16,22]. At the same time computer simulations of Ref.…”

“…Results of laboratory experiments and computer simulations, known from literature, very often contradict each other. Thus, contraction of the samples has been detected in the works [7,12,13,16], whereas elongation -in Refs. [8,19].…”

Microstructure of stomaflex based magnetic elastomers

“…The combination of magnetic and elastic properties leads to various phenomena which can be initiated by the external magnetic field [1][2][3][4][5][6][7]. These phenomena have opened up new possibilities for technological applications, such as: 1) magnetoelastic composites; with particles made of magnetostrictive hard or soft ferromagnetic material; 2) magnetorheological elastomers, for applications in the aerospace and automotive industries as actuators on antifriction components; 3) heat-shrinkable elastic ferromagnets with variable magnetic and conductive properties.…”

“…Many studies of the observed reinforcing effect of magnetic fillers have approached the problem from a magnetomechanical point of view, and investigated the microscopic properties through study of the magneto-elastic responses of the composity [1][2][3][4]. Less well understood, however, are the effects of the interactions between the filler and the surrounding polymer on submicroscopic length scales.…”