UV Treatments on Cotton Fibers

Abstract

Ultraviolet (UV) radiations can act in different ways on the functionalization of textiles, through pre-or posttreatments, in order to modify their behavior in dyeing and finishing processes. In cotton fiber, unlike the wool, the UV absorption is not due to any of the structural groups of the normal cellulosic chains and can only be attributed to "impurities" or "faults" bearing carbonyl and/or carboxyl groups. In fact, UV irradiation coupled with mild oxidation can improve some properties of the cotton fibers such as pilling resistance, water swelling, and dyeability. Therefore, the process of differential dyeing with direct and reactive dyes assisted by UV irradiation was studied and interesting differential chromatic effects were obtained by a UV posttreatment capable to fade dyeing. On the other hand, the surface modification of cotton fabrics by UV curing and UV grafting with suitable chemicals was pursued to obtain finishing treatments able to confer oil and/or water repellency. Finally, antimicrobial finishing by chitosan UV grafting was proposed as valid environmental friendly method to confer a satisfactory washing-resistant antimicrobial activity to cotton fabrics even with low polymer add-on.

Investigation of Bleaching of Cotton Fabrics with UV-TiO2

“…Although the UV treatment time did not seem to affect the strength values in general, it was observed that the strength values of the samples impregnated with the T+H solution decreased with increasing time. This is due to the reduction in strength values as a result of the attack of cellulose by oxidative radicals from H 2 O 2 under UV light [22]. Since NaOH slows down the oxidation process, no significant loss of strength was observed in the processes containing NaOH [21].…”

Advancements in Sustainable Natural Dyes for Textile Applications: A Review

“…Ultraviolet radiation (UV) is often used in cotton pretreatment as it introduces carboxylic groups onto the fabric surface which enhances interaction between the fabric and the dye molecules [ 99 ].…”

The coloration of polyester fabric with Prangos ferulacea natural dye: new approaches toward a cleaner production

“…Ultraviolet (UV) radiations can act in different ways on the functionalization of textiles, through pre- or post-treatment, to modify their behavior in dyeing and finishing processes (Ferrero et al , 2016). When the molecules on the surface of synthetic polymers are exposed to the UV lights, excitation and dissociation of the polymeric molecules by the short-wavelength UV radiation occur.…”

“…The UV treatments applied in textile, in addition to required specific effects, should also have the following advantages: easy application, not needing expensive and sophisticated equipment; limited treatment costs; and environmentally friendly requirements, for sustainable textile processes (Ferrero et al , 2016). …”