β-Cyclodextrin: Disperse yellow 211 complexes improve coloristic intensity of polyamide dyed knits

• Published in: Textile research journal Vol. 92; no. 13-14; pp. 2194 - 2204
• Main Authors: Bezerra, Fabricio Maestá, Carvalho Cotre, Dayane Samara de, Plath, André, Firmino, Helen Beraldo, Lima, Miliane Aparecida de, Lis, Manuel, Samulewski, Rafael Block, Moisés, Murilo Pereira
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.07.2022; Sage Publications Ltd
• Subjects: Adsorption; Aquatic environment; Color; Cyclodextrin; Cyclodextrins; Dispersion; Dyeing; Dyes; Isotherms; Kinetics; Polyamide resins; Polyamides; Thermal stability; Wastewater treatment; Dyeing; polyamide; color; cyclodextrin
• ISSN: 0040-5175; 1746-7748
• DOI: 10.1177/00405175211022624

Dyes are complex molecules that can sometimes cause damage to the aquatic environment and harm human health. They are often not completely removed from effluent by the usual treatments; therefore, efforts have been made to increase their exhaustion from dyeing through chemical and physical processes. In this context, the use of β-cyclodextrin (β-CD) as dyeing auxiliary agent promotes the reduction of harmful products, also increasing the color intensity of the fabric. In this paper, β-CD was used as a complexing agent to dye polyamide (PA) using the dye C.I. Disperse Yellow 211 (DY211) in order to improve dye exhaustion and color intensity using the β-CD:DY211 complex. The conventional dyeing process and β-CD:DY211 dyeing process by exhaustion were compared, and adsorption kinetics, isotherms, and the coloristic intensity were evaluated. The chemical shifts in the FTIR spectra and the thermal stability evidenced the formation of the β-CD:DY211 complex. Regarding dyeing kinetics and isotherm, the pseudo-first-order model was the most appropriate to describe the process, while Nernst isotherm was the one that best represented the adsorption results. Categorically, the samples dyed with the β-CD:DY211 complex obtained higher coloristic intensity in comparison with the conventional process. With this evidence, it is possible to conclude that cyclodextrin is a suitable replacement for environmentally harmful textile aides without adding further steps into the dyeing process or the need for additional equipment.