An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics

In the present study Terminalia chebula was used as an eco-friendly natural colorant for sustainable textile coloration of woolen yarn with primary emphasis on thermodynamic and kinetic adsorption aspects of dyeing processes. Polyphenols and ellagitannins are the main coloring components of the dye extract. Assessment of the effect of pH on dye adsorption showed an increase in adsorption capacity with decreasing pH. Effect of temperature on dye adsorption showed 80 °C as optimum temperature for wool dyeing with T. chebula dye extract. Two kinetic equations, namely pseudo first-order and pseudo second-order equations, were employed to investigate the adsorption rates. Pseudo second-order model provided the best fit (R2 = 0.9908) to the experimental data. The equilibrium adsorption data were fitted by Freundlich and Langmuir isotherm models. The adsorption behavior accorded well (R2 = 0.9937) with Langmuir isotherm model. Variety of eco-friendly and sustainable shades were developed in combination with small amount of metallic mordants and assessed in terms of colorimetric (CIEL∗a∗b∗ and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer). The fastness properties of dyed woolen yarn against light, washing, dry and wet rubbing were also evaluated

Dyeing studies and fastness properties of brown naphtoquinone colorant extracted from Juglans regia L on natural protein fiber using different metal salt mordants

In this study, wool fibers are dyed with a natural colorant extracted from walnut bark in presence and absence of mordants. The effect of aluminum sulfate, ferrous sulfate, and stannous chloride mordants on colorimetric and fastness properties of wool fibers was investigated. Juglone was identified as the main coloring component in walnut bark extract by UV visible and FTIR spectroscopic techniques. The results showed that pretreatment with metallic mordants substantially improved the colorimetric and fastness properties of wool fibers dyed with walnut bark extract. Ferrous sulfate and stannous chloride mordanted wool fibers shows best results than potassium aluminum sulfate mordanted and unmordanted wool fibers. This is ascribed due to strong chelating power of ferrous sulfate and stannous chloride mordants

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

First Application of Mix Metallic Salt Mordant Combinations to Develop Newer Shades on Wool with Bixa orellana Natural Dye Using Reflectance Spectroscopy

Annatto colorants derived from Bixa orellana L. seeds have been extensively used in a wide range of food commodities such as dairy products, flour confectionery, fish, soft drinks, meat products, snack foods, and dry mixes. To exploit its use as a colorant for textiles, this research study investigates for the first time pre-mordanting of wool with bi and tri metal salt combinations using aluminum potassium sulfate, ferrous sulfate, and stannous chloride mordants in order to develop natural and beautiful shades on wool with variation in hue and tone. The dyeing was carried by exhaustion method and dyed samples were analyzed using a Reflective Spectrophotometer in terms of CIELAB (L*, a*and b*) and K/S values and washing and light fastnesses were investigated according to I.S.O. standard recommendations. In the dyeing experiments, wool samples pre-mordanted with Fe + Sn displayed highest color strength followed by Fe + Al and Al + Sn combinations. The results showed that overall 36 different shades having good to very good fastness properties were produced by the use of different metallic salt combinations in the natural dyeing of wool using annatto dye

Adhatoda vasica in Conjunction with Binary Combinations of Metal Salts and Biomordants as an Effective Textile Dye to Produce novel Shades on Wool

This study was undertaken to propose an alternative use of Adhatoda vasica leaves extract as a potential source of natural dye for the coloration of woolen yarn/fibers. Premordanting technique was adopted with double metal salt combinations of ferrous sulfate, stannous chloride, and potassium aluminum sulfate and double biomordant combinations of gallnut, pomegranate, and babool, to achieve dyed textile materials of acceptable colorimetric and fastness properties. Sixty-three sober and elegant shades were developed on wool by varying the nature and the concentration of mordants involved in the combinations. The hue of color developed was found to be in yellow-red coordinate of color space diagram. All the dyed samples presented excellent color strength (K/S) values and highest values were found in case of gallnut + pomegranate peel extract (PPE) combination. Biomordants produced altogether different behavior in comparison to metal mordants in the development of ecofriendly shades of different hue and tune. Majority of the dyed samples showed excellent fastness properties with respect to light, washing, and rubbing which confirmed the possibility of using A. vasica leaves extract as an effective yellow natural dye

First-time application of biomordants in conjunction with the Alkanna tinctoria root extract for eco-friendly wool dyeing

Associated environmental hazards with the use of synthetic dyes and toxic metal mordants in the textile industry lead to concerns for alternatives. Natural dyes and biomordants are the new eco-friendly and biocompatible resources for textile coloration obtained from never-ending natural flora. The coloration potential of naphthoquinone-based colorants from Alkanna tinctoria roots on wool was investigated in this study with the application of both metallic mordants as well as biomordants. Color characteristics were evaluated on a spectrophotometer under the D65 illuminant, 10° standard observer, and fastness properties by using standard methods. A wide range of shades was obtained with good color characteristics and fastness results. Iron among metallic mordants, pomegranate peel extract (PPE) and babool among biomordants increased the color yield of dyed wool. Scanning electron microscopy (SEM) confirmed the undamaged physical structure and surface morphology of dyed wool

Exploiting the potential of polyphenolic biomordants in environmentally friendly coloration of wool with natural dye from Butea monosperma flower extract

Coloration of textiles with natural dyes involves huge consumption of chemicals; mainly, metal salt mordants, which pose serious environmental challenges. To mitigate this pollution, more and more environmentally friendly, biodegradable, biocompatible and renewable products should be popularized in dyeing industry. This paper proposes a sustainable and metal salt-free dyeing of wool samples by employing natural mordants extracted from pomegranate peel (Punica granatum L), gallnut (Quercus infectoria L) and catechu (Acacia catechu). The color parameters of dyed wool samples were greatly found to be dependent on the chemical compounds present in respective biomordants and their interaction ability with the functional groups of wool and the dye molecules. The investigated biomordants exhibit different interactions with coloring compounds of Butea monosperma (palas) dye resulting in deep brown, olive green, dark brown, cinnamon, burgundy, and yellowish hues on wool. All the biomordants selected in this study improved dye performance and resulted in a broad beautiful spectrum of colors with acceptable fastness properties. The results encourage the search and exploitation of new plant species as a source of biomordants to replace metallic and toxic mordants currently used in textile industry

Effect of binary and ternary combination of metal salt mordants on dyeing and fastness properties of natural protein fibre with Juglans regia L. dye

The present article focuses on the effect of different combinations of metal mordants on color characteristics and fastness properties of natural dye extracted from Juglan regia L bark powder. The influence of different types of mordant combinations such as alum + ferrous sulphate, alum + stannous chloride, ferrous sulphate + stannous chloride, and alum + ferrous sulphate + stannous chloride on color parameters has been investigated in terms of CIELab (L*, a*, b*, c*, and h°) and K/S values. The fastness properties with respect to light, washing, and crocking of developed shades were determined according to ISO and AATCC test methods. Based on the experimental results, it has been found that 96 shades with novel and fashionable hues were produced by the use of these metal salt combinations. It was also found that all mordanted samples had satisfactory light and wash fastness ratings. Dry rub fastness was found relatively better than wet rub fastness

Ecological dyeing of woolen yarn with Adhatoda vasica natural dye in the presence of biomordants as an alternative copartner to metal mordants

Introduction of natural dyes into modern dye houses is very promising green chemistry concept which should be popularized more and more to reduce the dependency of wool dyeing on some toxic and non-biodegradable synthetic dyes (Azo and benzidine dyes). In the present study, an attempt has been made to investigate the possibility of wool dyeing with Adhatoda vasica extract as a natural dye. A beautiful color palette of shades of varied hue and tone were obtained by using different mordants. The effect of various metal salts (ferrous sulphate, alum and stannous chloride) and natural tannin extracts (gallnut, pomegranate peel and babool bark) as mordants on color and fastness properties of dyed wool samples was comparatively evaluated. Dyeing experiments were performed with and without mordants, using pre-mordanting technique. The color of dyed woolen yarn was investigated in terms of CIELab (L*, a* and b*) and K/S values; and fastness properties were determined as per ISO and AATCC standard test methods. As confirmed by exhaustion studies, a substantial portion of metal salts remained in residual mordant baths. The results of using biomordants for wool dyeing were comparable with that of the metallic mordants in terms of color strength and fastness characterisctics. Biomordants produced quite different color gamuts as expected from a mordant and thus offer full potential to replace metal salts in wool dyeing

Dyeing of Wool with Anthraquinone based Natural Colorants from Cassia fistula fruit

The searches for new sources of natural dyes have been recently increased in many countries. This article is aimed to explore the dyeing potential of Cassia fistula as a source of natural dye on wool. In this study, the anthraquinone colorants are extracted from fruit of Cassia fistula by aqueous extraction method. Mordanting and subsequent dyeing of wool with extracted colorants were then performed to study the colorimetric and fastness properties. Three metallic salts aluminum sulfate, ferrous sulfate, stannous chloride and their combinations were used in this study to fix and increase the color as well as fastness properties of the substrate. UV visible and Fourier transform infrared spectroscopy (FTIR) analysis show identification of functional groups in the dye molecule. Colorimetric properties were analyzed by reflectance spectrometry in terms of L*, a*, b*, c*, h○ and K/S values. Color fastness was investigated in terms of light, wash and rub (dry/wet) tests. Results demonstrate that novel and fashionable brown shades with different hue and tone were obtained. Therefore, Cassia fistula has an exciting opportunity to be used as a source of natural dye in textile coloration