β-Cyclodextrin (β-CD) is an oligosaccharide composed of seven units of D-(+)-glucopyranose joined by α-1,4 bonds, which is obtained from starch. Its singular trunk conical shape organization, with a well-defined cavity, provides an adequate environment for several types of molecules to be included. Complexation changes the properties of the guest molecules and can increase their stability and bioavailability, protecting against degradation, and reducing their volatility. Thanks to its versatility, biocompatibility, and biodegradability, β-CD is widespread in many research and industrial applications. In this review, we summarize the role of β-CD and its derivatives in the textile industry. First, we present some general physicochemical characteristics, followed by its application in the areas of dyeing, finishing, and wastewater treatment. The review covers the role of β-CD as an auxiliary agent in dyeing, and as a matrix for dye adsorption until chemical modifications are applied as a finishing agent. Finally, new perspectives about its use in textiles, such as in smart materials for microbial control, are presented.

RESUMO O objetivo deste trabalho foi investigar as propriedades térmicas, mecânicas e termo dinâmico mecânicas de compósitos de polietileno de alta densidade (PEAD) com a incorporação do pó de conchas de moluscos (5, 10 e 20% em peso). A matriz pura e seus compósitos foram misturados em um misturador interno e em seguida moldados por compressão. A incorporação do pó de concha de molusco diminuiu o índice de fluidez do PEAD em uma faixa de 23 a 53%, já a cristalinidade da matriz praticamente não foi alterada. O pó da concha possui 97, 53% de CaO, tendo estrutura cristalina constituída por aragonita e calcita, ambos polimorfos do carbonato de cálcio. O estudo granulométrico mostrou que o pó da concha apresentou uma distribuição larga do tamanho das partículas, sendo também confirmada na análise da superfície de fratura dos compósitos por microscopia eletrônica de varredura. Os aspectos morfológicos mostram que nenhuma adesão foi observada entre as partículas e o PEAD. A adição da concha causou um aumento na rigidez da matriz e como também diminui a capacidade de amortecimento da matriz. A adição de 10% deslocou a temperatura de transição vítrea (Tg) do PEAD em 6 oC , enquanto o compósito com 20% do pó de concha não apresentou essa transição.

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.