Silk fibroin based magnetic nanocomposites for actuator applications

Abstract

The need for technologies based environmentally friendlier materials, able to minimize the global dependence on fossil fuel derivatives, promotes the development of new hybrid materials based on natural polymers, such as silk derivatives. This work reports on a new generation of magnetically active materials based on silk fibroin (SF) from Bombyx mori silkworm. Magnetic cobalt ferrite (CFO) nanoparticles are introduced in an SF polymer matrix to develop CFO/SF nanocomposites with filler contents of up to 20 wt%. It is shown that the inclusion of CFO nanoparticles affects the β‐sheet conformation of SF polymer having relevant effect on mechanical and thermal properties. The incorporation of conductive nanoparticles into nonconductive matrix, induces an increase in electric conductivity and also in dielectric constant. The primitive magnetic behavior of CFO nanoparticles is successfully maintained after their incorporation into SF, which has made possible the processing of magnetic SF. These results enable the design and fabrication of a fully functional magnetic actuator based on SF, proving the suitable natural polymer‐based magnetic materials for a new generation of environmental‐friendlier smart and multifunctional materials