Magnetic Plasticine™: a versatile magnetorheological material

Abstract

A novel black Plasticine™ was developed by dispersing iron microparticles into the paraffin wax–petroleum jelly composite matrix. Due to the presence of magnetic particles, this Plasticine™ exhibited magnetic-dependent mechanical properties and can be defined as a typical magnetorheological gel (MRG) material. The magnetic Plasticines™ were malleable and their mechanical properties were highly influenced by the iron contents. With increasing of the externally applied magnetic field, the shear storage modulus sharply increased. Under the optimum iron content, the magnetic induced modulus can be increased to as high as 4.23 MPa, whereas the relative magnetorheological effect was 305% and this value was higher than the reported magnetorheological elastomer (MRE). Interestingly, when the temperature reached a critical point, the magnetic Plasticine™ changed to a fluid like material which exhibited the typical characteristics of magnetorheological fluid (MRF). It was found the versatile magnetic Plasticine™ can seldom be transformed between the MRG and MRF without changing its dynamic properties.