Cotton fabric with durable flame retardancy, robust superhydrophobicity and reliable UV shielding

Abstract

A new strategy for multifunctional coatings with flame retardancy, superhydrophobicity and UV shielding ability on cotton fabrics (SFR cotton) was realized by step-by-step spraying ammonium phytate, lignin and hybrid nanoparticles of polydimethylsiloxane (PDMS) modified mesoporous silica nanoparticles (MSNs) with entrapped Fe₂O₃ (PDMS@Fe₂O₃-MSNs). The surface adhesion PDMS@Fe₂O₃-MSNs constructed micro/nano-scale surface structure on SFR cotton fabric, which endowed superhydrophobic (WCA = 152 ± 1.3°), anti-fouling and self-cleaning properties. Benefiting from the synergistic effects of the physical barrier provided by the PDMS@Fe₂O₃-MSNs and the intumescent flame-retardant properties of ammonium phytate and lignin, the SFR cotton fabric demonstrated excellent self-extinguishing performance under an open fire and left a char layer with 8.4 cm. In addition, due to the excellent UV-absorption ability of lignin and Fe₂O₃ nanoparticles, the SFR cotton fabric was able to shield the UV irradiation damages to rat skin. Furthermore, the SFR cotton fabric demonstrated remarkable durability against rigorous conditions, including ultrasonic washing, sandpaper abrasion, UV irradiation and exposure to strong acid/alkali environments. After 150 min of ultrasonic washing and 50 cycles of abrasion, the SFR cotton fabric could preserve its hydrophobicity, flame retardancy and UV shielding ability. In addition, the SFR cotton fabric delivered exceptional chemical stability and UV durability when exposed to strong acid/alkali for 24 h and UV irradiation (200 W) for 12 h, respectively. Significantly, the SFR cotton fabric could retain the original flexibility and breathability of pristine cotton fabric. Therefore, the simple and feasible strategy of multifunctional coatings has broad application prospects in advanced multifunctional textiles, military facilities and other fields.