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The Fluorescent Whitening of Textiles
Published in Menachem Lewin, Stephen B. Sello, Handbook of Fiber Science and Technology: Volume I Chemical Processing of Fibers and Fabrics, 2018
Raphael Levene, Menachem Lewin
The disadvantages of DASC type FWAs include: Photochemical instability. This is associated principally with the stilbene double bond, irradiation causing isomerization to the nonfluorescent and nonsubstantive cis isomer [95]. In addition photochemical transformations cause yellowing, or possibly cause the formation of products (e.g., cyclobutane dimers) fluorescing at lower wavelengths which overlap with the absorption band of the trans monomer. Though other stilbene-derived FWAs for cotton undergo such transformations [11, 83], many are known (including the DSBP type) which have greater photochemical stability and improved lightfastness (Fig. 3.8, FWAs 2–4).Once applied to the fabric, where the molecule has reduced mobility, DASC compounds are much more stable to light than when in solution, and they have acceptable lightfastness.Chlorination. The active nitrogen (-NH group) in DASC whiteners causes them to be incompatible with hypochlorite and chlorite bleaching agents. This has led to the development of other (more expensive) FWAs which can be used in conjunction with these bleaches. Once applied to the cloth, high affinity DASC whiteners are quite stable to hypochlorite bleach, but are destroyed by chlorite. It is possible that the -NH group is also involved in lightfastness, since stilbene FWAs without this group usually also have improved light stability.Other interfering agents. All anionic FWAs are incompatible with heavy metal ions such as those of copper, iron, manganese, and zinc [96]. If these are likely to be present, a chelating agent should be added. Resin finishes containing zinc salts and nitrates as cross-linking catalysts are known to cause rapid yellowing of goods finished with DASC whiteners, unless washed off very well after the treatment.
Smart textiles: an overview of recent progress on chromic textiles
Published in The Journal of The Textile Institute, 2021
Heloisa Ramlow, Karina Luzia Andrade, Ana Paula Serafini Immich
Dyeing of textiles using photochromic compounds results in some drawbacks such as compound degradation, limited interaction between compound and fiber matrix due to low dye uptake and decreased compound diffusion into the fibers, total inhibition of photochromism, constraints imposed by the hardness of the matrix and low washing and lightfastness characteristics. These drawbacks can be overcome by processing dyes into pigments using microencapsulation processes; although this methodology tends to increase the stability of the photochromic compounds, it usually confers a certain harshness and stiffness on the fabric, compromising the comfort of the user (Khattab et al., 2018). Several methods have been reported for the preparation of photochromic textiles, including conventional dyeing techniques to incorporate photochromic compounds into the polymer matrix inside textile fibers, and coating microencapsulated photochromic compounds onto textile surfaces. The durability of the surface coating with the photochromic compounds is determined by the mechanical strength of the coating and the adhesion between the coating layer and the substrate (Cheng et al., 2008b). Nevertheless, conventional processes of dyed photochromic textiles have disadvantages like complex synthesis, slower color switching speed, and poor handle (Fan et al., 2018).
A study of the effects of fabric pretreatment on color gamut from inkjet printing on polyester
Published in The Journal of The Textile Institute, 2018
Yi Ding, Lisa Parrillo-Chapman, Harold S. Freeman
Colorants used in textile inkjet inks include reactive, acid and disperse dyes and nano-scaled pigments. The chemical properties of these colorants also contribute to the quality of the interaction with the textile substrate (e.g. wet fastness) and lightfastness levels (Choi, Yuen, Ku, & Kan, 2004; Freeman & Posey, 1992; Fu, Zhang, Du, & Tian, 2011). Dyes for PET coloration such as C.I. Disperse Yellow 77, C.I. Disperse Blue 77, C.I. Disperse Red 109, and C.I. Solvent Yellow 163 (cf. Figure 1). Unlike disperse dyes, pigments used in PET coloration reside on the fabric surface at the end of the application process, due to their particular nature. Pigments used for digital printing include those shown in Figure 2.
Natural dyeing application of used coffee grounds as a potential resource
Published in International Journal of Fashion Design, Technology and Education, 2019
In addition, future research is recommended to investigate the effects of ultraviolet (UV) protection and lightfastness on fabrics dyed with used coffee grounds without mordant, because fabrics dyed with coffee, black tea, and green tea could contribute to 85–100% UV protection as opposed to protection provided by other undyed fabrics (El-Salamouny, Ranwala, Shapiro, Shepard, & Farrar, 2009). Therefore, the developed integrated natural dyeing approach may enable additional environmental and health benefits and could be applied in fashion industries in the production of outdoor sportswear or workers’ uniforms in order to protect human skin by blocking harmful UV rays in the future.