Polyvinyl alcohol (PVA)/montmorillonite (MMT) nanocomposite coatings via a rotational coating method

A custom-made rotational coating system that can apply constant, uniform, and high force to nanosheets was made. Montmorillonite (MMT) nanosheets and polyvinyl alcohol (PVA) chains were coassembled onto a poly(ethylene terephthalate) (PET) substrate using a rotational coating process. Different concentrations and centripetal accelerations were explored to study their effects on coating properties. The nanocoating thickness was determined by a thin-film measurement system and a stylus profilometer. The turbidity of the coating layer was determined using ultraviolet–visible (UV–Vis) spectrophotometry and the Beer-Lambert law. The nanostructure of the coating was characterized by X-ray diffraction (XRD). Finally, the oxygen transmission rate was measured to determine the effects of processing conditions on permeability. Two statistical approaches were used to determine the degree to which each processing parameter has an impact on each coating property. Aside from the fundamental study on rotational coating, this coating technique can fabricate highly ordered nanocoatings with significantly improved barrier properties. Potential applications are envisioned in the fabrication of food packages, dielectric materials, and biomedical devices.