Cathodic electrodeposition of organic nanocomposite coatings reinforced with cellulose nanocrystals

A systematic examination of the structure-property relations to create nanocomposite coatings via electrophoretic deposition (EPD) of a cathodic polymer - for instance, polyacrylate - reinforced with cellulose nanocrystals (CNCs) is discussed in this work. EPD, a scalable and green technique, has also been used in our approach to polymerize dopamine in the presence of CNCs and cathodic polymer to improve adhesion properties. This study investigated the interactions between CNCs, polydopamine (PDA) and the cathodic polyacrylic polymer to elucidate the dispersion state of the nanoparticles in the system by carefully examining ζ-potential, particle size, and electrophoretic mobility dependence in the colloidal suspension. We examined the morphology and structure of the electrodeposited nanocomposites using SEM and XPS, and the results indicate the formation of a compact, homogeneous structure. The incorporation of CNCs or PDA introduces different levels of roughness to the surface as revealed by AFM. Our results indicate improved adhesion, as determined by bond strength, using CNCs (>20%) or CNC-PDA (>30%) relative to the cathodic polymer, as well as significant improvement in hardness. The technique and materials used show promise to develop industrial organic coatings with low emissions for applications in automotive coatings and other applications.