The use of reflectance measurements in the determination of diffusion of reactive dyes into cellulosic fiber

Khatri, Awais; White, Max; Padhye, Rajiv; Momin, N

doi:10.1002/col.21764

Cited by 21 publications

(19 citation statements)

References 29 publications

(58 reference statements)

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“…It is known that the K / S value gives a direct measurement of the fabric surface colour strength, while the reactive dye fixation rate represents the actual amount of dye that has formed covalent bonds with the cotton fibre . The apparent colour depth of the fixed cotton fabric is negatively correlated with dye penetration into the fibre .…”

Section: Resultsmentioning

confidence: 99%

“…Dye distribution in the fibres of the dyed cotton fabric with a water content of 25.0% was also good (as shown in Figure 4b). This indicates that a water content of around a The dye liquor was composed of 25 g l À1 of dye and 30 g l À1 of Na 2 CO 3 , liquor pick-ups of the fabrics were 75.0 AE 2.0%, and all samples were steamed at 100 AE 1°C for 180 s. 25.0% was enough to keep reactive dyes adsorbed onto the fibres and allow penetration into the fibre interior during steaming. However, as dye penetration into the fibres of the padded fabric with a 25.0% water content was not as good as that with a 70.9% water content, the C * value of the former fabric is lower than that of the latter (as shown in Table 1).…”

Section: Colorimetric Parameters Of Dyed Fabrics With Various Water Cmentioning

confidence: 99%

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Effect of the water content of padded cotton fabrics on reactive dye fixation in the pad‐steam process

Zhang

Fang

et al. 2016

Coloration Technology

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A series of padded cotton fabrics with various water contents were obtained through vacuum dehydration. The effects of the water content on the fabric temperature variation during steaming, the colour properties, and the dye fixation rate (%F) were investigated. Dye distribution in the dyed cotton fibres was assessed. The influences of steaming time and sodium carbonate concentration on K/S value and %F of the dyed fabrics with low water content were also evaluated. The results indicate that reducing the water content of the padded cotton fabric to around 25.0% prior to steaming was favoured for reactive dyeing. The temperature of the wet fabric rose rapidly, the K/S value and %F were enhanced, and in addition the dye penetration into the dyed cotton fibres was sufficient. However, for padded fabrics with extraordinarily low and high water contents (e.g. 1.4% and 70.9% respectively), both the K/S value and %F were decreased. Furthermore, a white core phenomenon was evident for the fibres of the dyed fabric with a water content of 1.4%. Variation in the L* values was in line with the K/S values as the fabric water content varied. As expected, steaming time and sodium carbonate dosage can also affect reactive dye fixation greatly and should be determined accordingly for dyeing cotton fabric with low water content.

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Section: Resultsmentioning

confidence: 99%

Section: Colorimetric Parameters Of Dyed Fabrics With Various Water Cmentioning

confidence: 99%

Effect of the water content of padded cotton fabrics on reactive dye fixation in the pad‐steam process

Zhang

Fang

et al. 2016

Coloration Technology

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“…2 all can be measured experimentally, there is a great opportunity to use these relationships for advanced evaluation of the results of various staining protocols based on instrumental measurements. A Kubelka-Munk analysis has been used, for instance, by Khatri et al (2014), to account for the amount of dye uptake onto cellulosic fibers. The widespread availability now of powerful computing capabilities suggests that research ought to be done in this area.…”

Section: Kubelka-munk Analysismentioning

confidence: 99%

“…In some other studies the researchers made the assumption that the depth of staining depended more on whether or not the presumed adsorption sites could be reached by a diffusion mechanism, rather than being obstructed by dead-end pores or pores too small to allow passage (Maekawa et al 1989;Kim et al 2004;Yang et al 2013;Khatri et al 2014;Luterbacher et al 2015a). For instance, Luterbacher et al (2015a) used confocal laser scanning microscopy to support a mechanism by which the enzymatic widening of pores within lignocellulosic substrates tended to increase the rate at which dyes were able to permeate into the material.…”

Section: Permeabilitymentioning

confidence: 99%

Analytical staining of cellulosic materials: A review

Hubbe

Chandra

Doğu

et al. 2019

BioRes

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Numerous dyes and fluorescent compounds, as reported in the literature, exhibit specificity in the staining of materials associated with lignocellulosic fibers and their chemical components, including cellulose, hemicellulose, and lignin. Such effects long have provided analysts with convenient ways to identify cellulosic fiber types, products of different pulping methods, degrees of mechanical refining, estimates of accessibility to enzymes, and localization of chemical components within microscopic sections of cellulosic material. Analytical staining procedures allow for the facile estimation or quantification using simple methods such as light microscopy or UV-vis spectroscopy. More recent developments related to confocal laser micrometry, using fluorescent probes, has opened new dimensions in staining technology. The present review seeks to answer whether the affinity of certain colored compounds to certain cellulose-related domains can improve our understanding of those stained materialseither in terms of their fine-scale porous structure or their ability to accommodate certain colored compounds having suitable solubility characteristics. It is proposed here that successful staining ought to be viewed as being a three-dimensional phenomenon that depends on both the physical dimensions of the colored compounds and also on functional groups that influence their interactions with different components of lignocellulosic materials. Published information about the mechanisms of staining action as well as characteristics of different stain types is reviewed.

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“…This wash-off and subsequent effluent treatment, to remove the resultant color pollution, can account for up to 50% of the total cost of reactive dyeing. 8 Another extremely important sustainability consideration is the amount of water used in this wash-off process; a process involving over seven separate rinsing stages is not uncommon. High volumes of water and numerous repeated individual wash-off stages are often required to effect a dilution in electrolyte and alkali concentration in the wash-off bath; a wash-off process might include a cold water wash at 25-60 °C; a hot water wash at approximately 60-80 °C; scouring with anionic surfactant at 80-90 °C; followed by subsequent hot and cold water rinses.…”

Section: Introductionmentioning

confidence: 99%

Sustainable Chemistry Method to Improve the Wash-off Process of Reactive Dyes on Cotton

Amin

Blackburn

2015

ACS Sustainable Chem. Eng.

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Reactive dyes are extensively used for coloration of cellulosic fibers because of their excellent wash fastness (stability to washing with aqueous detergent solutions), which arises from covalent bond formation between dye and fibre. However, up to 40% of the dyestuff may hydrolyze in the dyeing process; this hydrolyzed dye has affinity for the fibre via hydrogen bonding and van der Waals interactions, but is not covalently bonded and as such exhibits poor wash fastness. Accordingly, these reactive dyeings require a multi-step 'wash-off' process after dyeing, 2 involving various aqueous rinses and washings, in order for the dyeing to achieve the characteristic very high wash fastness. Wash-off and subsequent effluent treatment can account for up to 50% of the total cost of reactive dyeing and consumes significant amounts of water and energy; from a sustainable chemistry and engineering perspective, consumption of water and energy are arguably the biggest issues in textile dyeing. Existing and developmental dye transfer inhibiting (DTI) polymers were employed to remove unfixed (hydrolyzed) dyes. It was found that the use of DTI in the wash-off of reactive dyes enables a much more efficient, economical and sustainable process to be developed, which significantly reduces operation time, water consumption and energy consumption. Different DTI polymer types varied in their efficacy of dye removal; poly(vinylpyridine-N-oxide) polymers were the most effective with respect to the level of hydrolyzed dye removal closely followed by the poly(vinylpyridine betaine) polymers, which were also highly efficient in hydrolyzed dye removal, with poly(vinylpyrrolidone) polymers being the least effective. These differences were attributed to variations in the magnitude and delocalization of positive electrostatic potential of the functional moieties in the polymers and the extent of and propensity for hydrogen bonding with the hydrolyzed reactive dyes. IntroductionCotton and other cellulose substrates comprise over 40% of world textile consumption. Of all the dyes employed for coloration of cellulosic fibers, reactive dyes find greatest use with over 50% of world consumption. [1][2][3] Reactive dyes are desirable because of their excellent wash fastness, which arises from covalent bond formation between dye and fibre through either 3 nucleophilic substitution or Michael addition reactions, depending upon the nature of the reactive group in the dye. Reactive dyeing essentially has two stages. In the first stage, the dye adsorbs onto the cellulosic substrate through hydrogen bonding and van der Waals interactions; dyes are applied from aqueous solutions with electrolyte (sodium sulfate or sodium chloride), 4 which is needed to overcome the long-range repulsion forces operating between anionic dyes (as a result of water-solubilizing sulfonic acid groups) and the negative zeta potential acquired by cotton surface in aqueous media. 5 Moreover, this repulsive force can be exacerbated through the formation of anionic carboxylic acid (COOH...

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The use of reflectance measurements in the determination of diffusion of reactive dyes into cellulosic fiber

Cited by 21 publications

References 29 publications

Effect of the water content of padded cotton fabrics on reactive dye fixation in the pad‐steam process

Effect of the water content of padded cotton fabrics on reactive dye fixation in the pad‐steam process

Analytical staining of cellulosic materials: A review

Sustainable Chemistry Method to Improve the Wash-off Process of Reactive Dyes on Cotton

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