Improving the actuation performance of magneto-polymer composites by silane functionalisation of carbonyl-iron particles

The interface between magnetic particles and polymer matrix is a key factor for the structural and actuation properties of magneto-composites. Herein we present a functionalisation method for carbonyl iron particles using epoxy silane. Experimental results from mechanical and electromagnetic tests reveal that this functionalisation increases the stiffness, fracture toughness and induction heating rates compared to composites with unfunctionalised particles. It was found that these performance improvements stem from the increase in interface bond strength by the silane functionalisation, which enables the polymer composites to sustain thermal loading without disbonding. The improved bonding between the magnetic particles and the matrix substantially enhances the actuation performance of the magneto-composites. To demonstrate the potential of the magneto-polymer composites, a novel thermal bimorph actuator was designed, manufactured, and characterised for reaction load and deflection control. [Display omitted] •An epoxy silane functionalisation method for carbonyl iron particles is presented.•Functionalised particles exhibited improved induction heating rates.•Improved matrix-particle bonding enhanced magneto-composite stiffness and toughness.•A novel thermal bimorph actuator was designed, manufactured and characterised.•Functionalisation substantially enhanced performance of actuator.