Encapsulation of ZnO nanoparticles in POSS for robust anti-photofading coatings on dyed fabrics

Abstract

As an excellent UV absorber, zinc oxide nanoparticles (ZnO Nps) are limited applications in anti-photofading coating fields due to the high photocatalytic degradation activity, which can accelerate dyed fabrics fading. Herein, a “core-shell” shaped composite nanoparticles with high UV absorption and low photocatalytic degradation properties were successfully fabricated by encapsulating ZnO Nps in polyhedral oligomeric silsesquioxane (POSS) via the alkaline hydrolysis method, and then the POSS coated ZnO Nps (ZnO@POSS Nps) were applied as UV absorber to improve the photostability of dyed polyester fabrics. Field emission scanning electron microscope, Fourier transform infrared spectroscopy and X-ray diffraction analysis confirmed the strong relevance between the POSS shell thickness and micromorphology and structural interface characteristics of “core-shell” shaped ZnO@POSS Nps. The UV–Vis absorption spectrum of ZnO@POSS Nps and C. I. Red 2 degradation experiments indicated when the mole ratio of ZnO to vinyl trimethoxy silane was 1:0.25, ZnO@POSS Nps maintained high comparative UV absorption performance (65.4 %) and restrained the photocatalytic degradation efficiency from 62.0 % to 8.9 % comparing with ZnO Nps. The photostability of fabrics was significantly improved by the presence of ZnO@POSS Nps in the coatings that the color difference values of all three dyed fabrics exposed to strong UV light for 72 h were decreased from 2.62, 2.29, and 3.04 to 1.17, 1.09, and 1.52, respectively. This work presents an effective and simple way to restrain the photocatalysis activity of ZnO Nps and enhance the anti-photofading property of dyed fabrics.