One-step brush-coating strategy for low-haze and water-resistant transparent wood films

The wood film (WF) fabricated by top-down wood nanotechnology possessed high mechanical strength, low energy consumption, environmental friendliness, and easy preparation, however, the high optical haze and poor water-resistant have seriously hindered its practical application. In this work, the epoxy resin was directly brushed on the surface of the WF, which can not only effectively reduce the haze of the WF, but also protect the WF to avoid the adverse effect of water on it. Compared with the untreated WF, the epoxy resin-coated wood film (WEF) showed low haze, which decreased from 76 % to 43 % at a wavelength of 550 nm. Meanwhile, the water-resistant property was effectively improved. The WEF could keep its shape intact and strength in agitated water, whereas the WF quickly disintegrated to form fine fibers. In addition, the longitudinal and transverse tensile strengths of the WEF were 157.2 MPa and 21.1 MPa. The WEF exhibited excellent optical properties, water-resistant performance, flexibility, and high strength, which could significantly broaden its application fields.