Sonochemical synthesis of flower-like ZnO assembled by hollow cones toward water vapor permeability and water resistance enhancement of waterborne film

Abstract In this study, flower-like ZnO assembled by hollow cones (F-ZnO-HCs) were synthesized via sonochemical route and the related morphology and structure of product were characterized. Then, F-ZnO-HCs nanostructures were employed to polyacrylate and the effect of F-ZnO-HCs on the properties of waterborne films was investigated. Meanwhile, the morphological evolution of F-ZnO-HCs was proposed and the superiority of F-ZnO-HCs on synchronously improving the water resistance and water vapor permeability of polyacrylate film was discussed. The results showed that F-ZnO-HCs possessed an average diameter of ∼800 nm and a large specific surface area of 16.01 m2g-1. Adjusting the water content and citric acid dosage, the morphology of ZnO transformed from F-ZnO-HCs to ZnO nanoparticles, F-ZnO-NSs, F-ZnO-SCs and F-ZnO-NRs. F-ZnO-HCs nanostructures as fillers not only significantly enhance the stability of polyacrylate latex but also simultaneously improve the water vapor permeability and water resistance of polyacrylate film. Moreover, compared with other morphological ZnO, F-ZnO-HCs was the best for simultaneously improving the water resistance and water vapor permeability of polyacrylate film. F-ZnO-HCs is an ideal candidate for resolving the contradiction of the water resistance and water vapor permeability of waterborne films.