Fabrication and UV-blocking property of nano-ZnO assembled cotton fibers via a two-step hydrothermal method

A novel ZnO/cotton composite, in which ZnO nanoparticles were synthesized directly inside of the lumen and the mesopores of cotton fibers, was fabricated via a simply two-step hydrothermal method in situ using zinc nitrate hexahydrate and hexamethylenetetramine as raw materials. The as-obtained cotton sample was characterized by powder X-ray diffractometer, field emission scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The UV-blocking property of the as-obtained sample was investigated by UV–vis spectrophotometry. The results showed that hexagonal wurtzite nano-ZnO with a diameter of about 30–40 nm was successfully assembled into the lumen as well as the mesoporous structure of the cotton fibers. The UV-blocking property of the modified cotton fibers can be greatly improved by assembling nano-ZnO into the inner of cotton fibers. Comparing with the neat cotton fibers, the UV-blocking ratio of the ZnO assembled cotton fibers inside of KBr disk could reach 80% at 300 nm and 95% at 225 nm, respectively. Therefore, it demonstrated a significant advance in protective functional treatment and provided a potential commercialization.