Modified TiO₂@graphene oxide and montmorillonite synergistically enhanced multifunctional nanocomposite films

Abstract

The application of polymers in packaging is still limited due to the problems of poor gas barrier and flame retardant properties. Herein, a modified TiO 2 (m-TiO 2 )@graphene oxide (GO)/montmorillonite (MMT) filler-reinforced polyvinyl alcohol (PVA)-based nanocomposite films with excellent gas barrier, flame retardant, and mechanical properties is fabricated through a simple method of solution casting. In this system, GO and MMT act as bricks, PVA sticks them together like glue, and they together form a brick-wall structure. By adding these fillers, the oxygen permeability rate (Po 2 ) of this film is 0.48 × 10 −18 cm 3 •cm/(cm 2 •s•Pa), less than that of pure PVA film by 97%, and the water vapor permeability rate (P H 2 O ) of the nanocomposite film is 1.21 × 10 −13 g•cm/(cm 2 •s•Pa), less than that of pure PVA film by 86%. In addition, the flame retardant properties of m-TiO 2 @GO/MMT/PVA nanocomposite films are excellent, which self-extinguishes as long as the flame taken away, different from pure PVA film, which is completely burned. Moreover, the thermal stability and mechanical properties of the nanocomposite films are also significantly improved. The nanocomposites with environmentfriendly raw materials, simple manufacturing processes, and excellent performance should have good applications in the packaging and coating industries.flame retardant, gas barrier, graphene oxide, montmorillonite, polyvinyl alcohol | INTRODUCTIONPolymers are widely used in the packaging field because of their lightness, cheapness, and easy availability. [1] Considering that some products like food are easily oxidized to deteriorate by oxygen in the air, the barrier properties of packaging materials are very important; [2] and the flame retardant properties of polymer packaging materials cannot be ignored too. The commonly used polymer packaging materials generally have no flame retardant properties, which makes these materials have greater safety risks during daily storage and use. [3]