Biomimetic strategy for electrophoretic deposition of composite ferroelectric poly(vinylidene, fluoride-co-hexafluoropropylene) – ferrimagnetic NiFe2O4 films

This investigation is motivated by interest in fabrication of composite films combining ferrimagnetic properties of spinel ferrites with multifunctional properties of ferroelectric polymers. It addresses the need in the development of surface modification techniques for inorganic materials and polymers and their electrophoretic deposition (EPD) for the fabrication of composite films. This article describes for the first time the fabrication of composite ferroelectric poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) - ferrimagnetic NiFe2O4 films by EPD. The approach is based on feasibility of fabrication, surface modification and EPD of PVDF-HFP particles using natural biosurfactants, such as catecholate-type caffeic acid (CA) and bile acid-type cholic acid (ChA). The analysis of chemical structure of CA and ChA provides an insight into the surface modification mechanisms and EPD efficiency. Film morphologies and corrosion protection properties are analyzed. An important finding is the ability of CA to act as a charging dispersant for materials of different types, such as PVDF-HFP polymer particles and inorganic nanoparticles of NiFe2O4 spinel and fabrication of composite films by EPD. The film deposition yield, morphology and composition of PVDF-HFP - NiFe2O4 films are analyzed. NiFe2O4 content and magnetic properties of the composites are varied by variation of EPD bath composition. This investigation provides a platform for EPD of composite films combining ferrimagnetic properties of spinel ferrites with multifunctional properties of ferroelectric polymers.