Magnetic leathers

Abstract

Leather, a stable chromium–collagen matrix, is insensitive to magnets although it is paramagnetic. Here we show that the coating of the leather surface with iron oxide nanoparticles can provide magnetic leathers showing significant responses to permanent magnets. Iron oxide nanoparticles, synthesized using a simple co-precipitation technique, predominantly comprised magnetite (Fe₃O₄) with a particle size around 16 nm as revealed through X-ray diffraction and scanning electron microscopic analyses. Ethanol dispersed nanoparticles were mixed with commercial leather finishing dispersion and coated on the leather surface. Vibrating sample magnetometric measurements show that the resulting ferromagnetic effect is comparable to the leathers coated with commercial magnetic pigments. Surface coating of leathers with magnetic nanoparticles did not affect any of the physical properties of the leather. We further demonstrate that the prepared magnetic leathers have potential for advanced applications including adhesive-free wall tiling and energy harvesting from human motions.