Electrophoretic deposition of composite chitosan–halloysite nanotube–hydroxyapatite films

Electrophoretic deposition (EPD) method has been developed for the deposition of halloysite nanotubes (HNT) and fabrication of composite chitosan–HNT and chitosan–HNT–hydroxyapatite(HA) films. The use of chitosan as a dispersing and charging agent for both HNT and HA allowed the formation of chitosan–HNT–HA monolayers, films of graded composition and multilayer laminates, containing different layers. The quartz crystal microbalance method was used for the investigation of the deposition kinetics. The composite films were studied by X-ray diffraction, thermogravimetric analysis, differential thermal analysis and electron microscopy. The deposition yield, thickness of the films or individual layers and their composition can be varied. The results of potentiodynamic studies in the simulated body fluid solutions showed that the films provided corrosion protection of the stainless steel substrates. The composite films are promising materials for fabrication of biomedical implants with advanced functional properties.