Morphology and gas transport properties of acrylic resin/bentonite nanocomposite coatings

• Highly dispersed exfoliated acrylic resin/bentonite nanocomposite coatings.
• Made from aqueous colloidal suspensions of exfoliated particles/monomer droplets.
• Tortuosity imposed by large L/D particles reduces the diffusion coefficient.
• Interfacial free volume enhances solubility and compromises final gas barrier properties.

This is a study of the addition of hydrophilic bentonite nano-platelets in acrylic polymer resin to make nano-composite coatings. The mechanism of the dispersion of the nano-platelets during film formation and curing form aqueous suspensions is described. The morphological features of the coating and the degree of exfoliation are examined via X-ray diffraction. The impact of the solvent evaporation rate on the properties of the film is studied. The influence of the shape of the nano-sized objects and their dispersion level on the transport characteristics of the nanocomposite film is measured and their effect on the polymer free volume is discussed.