Fabrication of UV-resistant and superhydrophobic surface on cotton fabric by functionalized polyethyleneimine/SiO2 via layer-by-layer assembly and dip-coating

In this research, a water-soluble ultraviolet (UV) absorber (PEI-H) was synthesized by grafting polyethyleneimine (PEI) with 2,4-dihydroxybenzophenone (UV-0). UV-resistant and superhydrophobic coating was fabricated upon cotton fabric by sequentially depositing PEI-H, silica sol (SiO2) and hexadecyltrimethoxysilane via layer-by-layer assembly and dip-coating. The surface morphology, chemical composition, water-repellence, UV resistance property, durability against washing and abrasion test, air permeability as well as safety of the obtained fabric were investigated. It found that the obtained cotton fabric exhibited superior UV-resistant property with UPF value more than 800 which was attributed to the synergistic effect between organic UV absorber (UV-0) and inorganic UV shielding agent (SiO2). Meanwhile, it also possessed superhydrophobicity, self-cleaning and anti-fouling properties with water contact angle of 154 degrees. In addition, the multifunctional fabric after 20 washing times or 300 abrasion times remained excellent hydrophobicity and the corresponding UPF values were still 400+, showing an outstanding durability. Importantly, the obtained fabric was absolutely safe for human body. Graphic abstract