Effect of polyester blends in hydroentangled raw and bleached cotton nonwoven fabrics on the adsorption of alkyl-dimethyl-benzyl-ammonium chloride

Abstract

The adsorption kinetics and isotherms of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on hydroentangled nonwoven fabrics (applicable for wipes) including raw cotton, bleached cotton, and their blends with polyester (PES) were studied at room temperature. The adsorption kinetics of ADBAC on all nonwoven fabrics was best described by the pseudo-first-order kinetic model. Unlike bleached cotton/PES blends, the equilibrium adsorption capacities of ADBAC on raw cotton/PES blends were enhanced in comparison with predictions based on the binary mixing rule. The adsorption rates for raw cotton, determined by the KASRA (kinetics of adsorption study in the regions with constant adsorption acceleration) model and Elovich equation, were significantly greater than those for bleached cotton, resulting in a rapid decrease of adsorption rates when blending with PES, which has a negligible interaction with ADBAC. This distinctive adsorption property of raw cotton was attributed to its unique surface characteristics induced by the hydroentangling process: retained pectin, partial removal of waxes, and surface fibrillation, which enhance electrostatic interaction, hydrophobic interaction, and accessible surface area to ADBAC, respectively. In adsorption isotherms, raw cotton/PES blends exhibited a non-linear decrease in maximum adsorption capacity and monolayer adsorption capacity, calculated by the Langmuir and Langmuir-type equations, respectively, as a function of PES blend ratio.