The Absorption Accelerating Behavior of Surface Modified Wool: Mechanism, Isotherm, Kinetic, and Thermodynamic Studies

Abstract

ABSTRACT Even though wool has excellent fabric properties, its low absorption capacity hinders its efficient application in the textile industry and material field. Surface modification is one of the efficient ways of improving its inherent properties. However, the effect of surface modification on its absorption properties is not well understood. Herein, surface modification of wool was performed using deep eutectic solvent method. Several physical and chemical properties of the modified wool including chemical bonds, surface topography, and absorption capacity were analyzed. FTIR revealed that surface modification retained keratin molecular structure but only cleaved disulfide bonds. The second-derivatization of FTIR spectra further indicated that the secondary structure was also retained. SEM and EDS analyses revealed that scale modification etched the wool surface. Together, these changes improved the absorption capacity of wool. BET further revealed that surface modification increased the pole size of wool, a property that improves the adsorption capacity. Further analyses on diffusion coefficient, adsorption isotherm, adsorption kinetics, and thermodynamic parameters at a lower temperature revealed that surface modification followed Langmuir to Freundlich isotherm and pseudo-first-order model to pseudo-second-order model transformation. In particular, the adsorption content, rate and diffusion coefficient increased with decrease in the entropy and enthalpy of wool.