Synergistic Stain Removal Achieved by Controlling the Fractions of Light and Thermo Responsive Components in the Dual-Responsive Copolymer Immobilized on Cotton Fabrics by Cross-Linker

Abstract

Enhanced synergistic stain removal is realized by tailoring the comonomer fractions of a light- and thermo-dual responsive copolymer, which is immobilized on cotton fabrics by a cross-linker. The copolymer poly­(acrylamide azobenzene-co-ethylene glycol methacrylate-co-triethylene glycol methyl ether methacrylate), denoted P­(AAAB1-co-EGMA2-co-MEO3MA17), is prepared by the ATRP polymerization method. The present molar ratio for these monomers is 1:2:17. Because of the existence of the light-responsive AAAB unit, the transition temperature of its aqueous solution under UV radiation is shifted to 39 °C, which is 2 °C higher than that in ambient conditions. This increase is caused by the trans–cis isomerization from the azobenzene groups, indicating an increased hydrophilicity of P­(AAAB1-co-EGMA2-co-MEO3MA17) under UV radiation. After being immobilized onto cotton fabrics by a cross-linker, they are also dual-responsive. The equilibrium swelling ratio (ESR) of the cotton fabrics is further increased after UV radiation. Compared to our former investigation, the reduction of the AAAB molar fraction from 0.1 to 0.05 causes an increase of the ESR value by 10%. Moreover, the stain removal efficiency of the cotton fabrics immobilized with P­(AAAB1-co-EGMA2-co-MEO3MA17) by cross-linker is also significantly improved under UV radiation. The hydrophilicity of the copolymer mainly from the MEO3MA units is crucial to the cleaning capability. Additionally lowering the attachment between stain and the copolymer coating on the cotton fabrics by trans–cis isomerization in those AAAB units also favors the cleaning. Hence, the stain removal is strongly improved by optimizing the fraction of light- versus thermo-responsive components in the copolymer, which can profoundly reduce the consumption of chemical detergents and energy during laundry.

Robust multifunctional fluorine-free superhydrophobic fabrics for high-efficiency oil–water separation with ultrahigh flux

“…As a natural fiber, cotton fabric with low cost and high yield has been widely used in industries and households owing to comfort, softness, breathability, wash resistance and moisture absorption. 23,24 Modifying cotton fabrics to be superhydrophobic will expand their applications in oil-water separation [25][26][27][28] and self-cleaning, [29][30][31] thus many representative methods have emerged including, spray-coating, 32 phase separation, 33 layerby-layer self-assembly, and chemical vapor deposition. 34 However, there are many issues in the above methods such as complicated preparation process, expensive equipment, long reaction time, and toxic fluorine-containing low-surface-energy material, restricting large-scale applications.…”

Preparation of Structural Color on Cotton Fabric with High Color Fastness through Multiple Hydrogen Bonds between Polyphenol Hydroxyl and Lactam

“…The washing fastness of the PDA-decorated cotton fabric was tested in a 250 mL conical flask containing 150 mL of deionized water by magnetically stirring with a speed of 150 r/min for 0.5 h under a water bath with 40 °C. After that, the oven-dried structural colored cotton fabric was evaluated for the washing fastness through optical photographs, weight loss ratio, – K/S, and reflectance spectroscopy. This washing procedure was repeated at least three times to get an averaged weight loss ratio of the structural colored cotton fabrics.…”

Nonwoven Membranes with Infrared Light-Controlled Permeability

“…Measurements of washing fastness were conducted by following the methods outlined in prior work. − Dry (GO) 6 x NWF samples were individually placed in an Alconox aqueous solution (bath ratio, 1:50; concentration, 1 mg·mL –1 ) and stirred at a speed of 300 rpm for 20 min at room temperature. The samples were then rinsed copiously with deionized water and dried at 60 °C.…”