Facile Preparation of Polyacrylic Acid-Bentonite Nanocomposite Inks for Gas Barrier Thin-Films with Ultrasonic Treatment

The facile fabrication of an organic-inorganic hybrid nanocomposite film was investigated for a cost-effective gas barrier coating. Highly stable PAA/bentonite nanoink dispersion was achieved with high power ultrasonication treatment. The bar-coated PAA/bentonite film on PET substrate showed high barrier performance of oxygen transmission rate (OTR) value of 0.86 cc/m 2 ·day at optimized nanoink concentration (5 wt%). In contrast, the OTR value was increased about 200 times with high ink concentraton (20 wt%). The detailed analysis of film morphology and microstructure revealed that the optimization of gas barrier properties have been achieved with proper clay platelet alignment and efficient water removal at interlayer. The gas barrier properties of one-step bar-coated barrier in this study provide industrially scalable simple gas barrier coating method for food and pharmaceutical packaging application.