ZnO nanoparticle/poly(vinyl alcohol) nanocomposites via 2 microwave-assisted sol−gel synthesis for structural materials, UV 3 shielding, and antimicrobial activity

Abstract

Polymer nanocomposites based on poly(vinyl alcohol) (PVA) and ZnO hold a privileged position in the development of organic/inorganic hybrid multifunctional materials for applications ranging from food packing to biotechnological platforms. However, a remarkable drawback is that most of the currently available synthetic routes are based on approaches that are both time- and energy-consuming and often lead to heterogeneous polymer films that require compatibilizers to disperse inorganic nanoparticles into the organic matrix. In this work, we present a route for synthesizing ZnO_PVA nano-composite films through a sol−gel strategy that uses microwaves as a heat source and PVA as a reactant. We show that nanocomposites produced using this approach exhibit enhanced mechanical properties, UV shielding capabilities, and antimicrobial activity and potentialize their application in the production of antibacterial films against Gram-positive and Gram-negative strains. We show that these properties are easily modulated by controlling the synthesis parameters, such as the irradiation time and power, and the use of PVA excludes the need for compatibilizers since it simultaneously behaves as the polymer matrix and a mediator for in situ synthesis of nanostructured ZnO clusters. The method presented here is straightforward, inexpensive, and applied to other polyols to enhance the functionalities of materials based on these compounds.