Microwave and Ultrasonic Irradiation Pretreatment for Efficient Dyeing of Cotton Fabrics with Reactive Red 195

Low efficiency and poor color build-up are the major shortcomings of traditional pretreatment method applied for dyeing of cotton fabrics. In the present work, we report microwave (MW) and ultrasonic (US) irradiations pretreatment methods for high-quality dyeing of cotton fabrics with Reactive Red 195. Importantly, compared to the control method, MW and US irradiations pretreatment increased the color strength value (K/S) 1.8 and 2.6-folds, respectively. Detailed evaluation of the irradiation pretreatment processes reveals that bleaching is the most important step for both MW and US irradiations. Temperature, time, NaHCO₃ and urea concentration were also examined for dyeing of MW or US pretreated fabrics. FT-IR, Raman, XRD, and FE-SEM characterization proved that irradiations did not affect the chemical nature of the cotton fabrics but can increase the roughness for easy formation of bonded dyes.