Efficient extraction of textile dyes using reusable acrylic-based smart polymers

Abstract

Water pollution from industrial or household waste, containing dyes from the textile industry, poses a significant environmental challenge requiring immediate attention. In this study, we have developed a crosslinked-smart-polymer film based on 2-(dimethylamino)ethyl methacrylate copolymerized with other hydrophilic and hydrophobic commercial monomers, and its efficacy in removing 21 different textile dyes was assessed. The smart polymer effectively interacts with and adsorbs dyes, inducing a noticeable colour change. UV-Vis spectroscopy analysis confirmed a removal efficiency exceeding 90 % for anionic dyes, with external diffusion identified as the primary influencing factor on process kinetics, consistent with both pseudo-first-order kinetics and the Crank-Dual model. Isothermal studies revealed distinct adsorption behaviors, with indigo carmine adhering to a Freundlich isotherm while others conformed to the Langmuir model. Permeation and fluorescence analyses corroborated isotherm observations, verifying surface adsorption. Significantly, our proof-of-concept demonstrated the resilience of the smart-film to common fabric softeners and detergents without compromising adsorption capacity. Additionally, the material exhibited reusability (for at least 5 cycles), durability, and good thermal and mechanical properties, with T5 and T10 values of 265 °C and 342 °C, respectively, a Tg of 168 °C, and a water swelling percentage of 54.3 %, thus confirming its stability and suitability for industrial application.