A UV-shielding and hydrophobic graphitic carbon nitride nanosheets/cellulose nanofibril (gCNNS/CNF) transparent coating on wood surface for weathering resistance

A UV-shielding, Hydrophobic and transparent coating was developed to improve the weathering resistance properties of wood materials while maintaining the natural aesthetic texture of the wood. Graphitic carbon nitride nanosheets (gCNNS) were used as nontoxic and metal-free UV absorber. Cellulose nanofibril (CNF) was selected as an environment-friendly and renewable film-forming carrier, which addressed the issues of agglomeration and low composite adhesion of gCNNS on the wood surface. The gCNNS/CNF composite coating was formulated on the wood surface via spin coating method. The following hydrophobic treated by thermal chemical vapor deposition (CVD) method was to solve the problem of rainwater erosion in outdoor application. After 15-day accelerated weathering tests, the total color change of the treated sample was 79.6% lower than that of the untreated one. Our newly-designed environment-friendly and weathering resistance coatings will be applied to a wide variety of substrates in the future.