Theoretically optimized hybrid magnetic nanoparticle concentrations for functional gradient nanocomposites

Magnetically actuated functional gradient nanocomposites have widely been used for ultra-durable biomimetic interfaces and surfaces. However, the mechanical and thermal mismatches in integrated systems containing dissimilar materials or structures usually cause failures. By modulating the concentration of magnetic particles, a suitable mechanical gradient morphology can be generated to match different integrated systems. In this work, a new model is developed to describe magnetic particle motion under the magnetic field. Hybrid nano-reinforcements with two different magnetic particle sizes and concentrations were employed to optimize the magnetic particle concentration gradient. It was observed that the diversification of concentration distribution can be achieved by tuning the sizes and concentrations of nanoparticles. The present study, therefore, contributes toward the understanding of the transport mechanism of magnetic-field-actuated functional gradient nanocomposites and provides guidance for experiments to design ultra-durable biomimetic interfaces and surfaces.