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The purpose of this study was to review the information on the scientific efforts and achievements in sustainable industrial textile applications of natural colourants. Then the…
Abstract
Purpose
The purpose of this study was to review the information on the scientific efforts and achievements in sustainable industrial textile applications of natural colourants. Then the paper suggests the ways of improving the industrial textile applications of plant-based colourants.
Design/methodology/approach
The literature on the chemistry, sources and extraction of plant-based natural colourants was reviewed. The reviewed information was analysed and synthesised to provide techniques for selecting sustainable extraction methods, possible sustainable textile applications of natural colourants and the challenges which hinder industrial textile applications of plant-based natural colourants. The ways of overcoming the challenges of the industrial textile applications of plant natural colourants were suggested. Lastly, the current situation of industrial application of natural dyes in textiles is presented.
Findings
Despite the scientific achievement to overcome the challenges of natural colourants for textiles, the global industrial application of natural colourants is still low. Inadequate knowledge of the dyers results into poor performance of the natural dyed textile. The natural dyed textiles are expensive due to the scarcity of raw materials for manufacturing of natural colourants. The selection of suitable extraction, application methods and type of substrate should consider the chemistry of the particular colourant. The society should be educated about the benefits of natural dyed textiles. Cultivation of colourant-bearing plants should be promoted to meet the industrial material demand.
Originality/value
The paper provides a synthesized collection of information about the source, chemistry, extraction, textile application and challenges of plant-based natural colourants. The reviewed information was analysed and synthesised to provide techniques for selecting sustainable extraction methods, possible sustainable textile applications of natural colourants and the challenges which hinder industrial textile applications of plant-based natural colourants. The ways of overcoming the challenges of the industrial textile applications of plant natural colourants were suggested.
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Zahra Bazrafshan, Maryam Ataeefard and Farahnaz Nourmohammadian
This paper aims to report on production of the colour digital printing toners cyan, magenta and yellow. Colour digital electrophotographic printing is currently in high demand…
Abstract
Purpose
This paper aims to report on production of the colour digital printing toners cyan, magenta and yellow. Colour digital electrophotographic printing is currently in high demand. The provision of a large colour gamut depends on appropriate selection of precise colourants to produce toner capable of producing a thin layer on paper.
Design/methodology/approach
Printing toners were synthesised by the emulsion aggregation method, and then evaluated for chemical constitution and effects of the colourant substituents.
Findings
Results demonstrated that increasing the polarity of a pigment produced better dispersion and lower particle size with narrower distribution and even better colour reproduction. While, changing a pigment’s characteristics did not affect the toner shape or its thermal properties.
Practical implications
The developed method provides a simple way to synthesise colour printing toner.
Social implications
Emulsion aggregation toners provide less hazardous materials during printing.
Originality/value
Evaluations of the influence of solid-state parameters and physicochemical properties of the pigments on printing toner characteristics were done for the first time.
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Divya V., Divya Jayan and Asoka Kumar
As there is a strong inducement to develop new colored inorganic materials to substitute the current industrial pigments that are based on toxic metals hazardous to health and the…
Abstract
Purpose
As there is a strong inducement to develop new colored inorganic materials to substitute the current industrial pigments that are based on toxic metals hazardous to health and the environment, the purpose of this paper is to invent environmentally benign rare earth-based colorants as viable alternatives to the traditional toxic pigment formulations. Herein, the authors developed a series of rare earth pigments having the general formula Ca0.1 Ln0.9 PO4 ( Ln = Y , Pr , mixed rare earth oxides, RE and Di). After studying all the optical properties, the authors have gone for some coloring application in plastic like PMMA.
Design/methodology/approach
The designed pigments were synthesized by traditional solid-state method. Stoichiometric amounts of each reagent were mixed in an agate mortar and the mixtures were calcined at optimized temperature 1000 °C for 4 h in electric furnace followed by auto–cooling. The samples were characterized by X-ray diffraction diffraction, UV–vis spectroscopy, scanning electron microscope (SEM), particle size distribution, color coordinates determination, acid/alkali test, thermo gravimetric (TG) analysis and CIE–1976 L*a*b* color scales. Among the various lanthanide ions and calcium ion as dopant, the pigment composition shows various hues ranges from green to yellow. The designed pigments consist of non–toxic elements and were further found to possess high thermal and chemical stability. The pigments were also found to be appropriate candidates for the coloration of polymer substrates like PMMA.
Findings
The present investigations establish that various color hues can be achieved by the incorporation of suitable chromophore metal ions like calcium in various rare earth host lattice by tuning of the band gaps. The coloring mechanism is based on the strong absorption of the pigments in the blue and red regions due to electronic transitions of the micro states of rare earth ion. The pigment composition shows various hues ranges from green to yellow. The coloring mechanism is based on the tuning of band gap by the dopant like calcium in various rare earth host lattice. In addition, this pigment was chemically and thermally stable. Finally, it has applied in plastics like PMMA.
Research limitations/implications
Mechanism of the color appearance using band calculations and on possible applications of rare earth phosphate powders as pigments in plastics and paints have not been explored much. However, the properties of the Ca-doped rare earth phosphate implies that this material has a potential to be applied as a satisfactory pigment for coating or coloring except for glaze, which may cause a side reaction at high temperatures, especially taking into consideration the economics and ecologies. The possibility of Ca2+ incorporation in CePO4 with monazite structure-type has been established.
Practical implications
The designed pigments consist of non-toxic elements and were further found to possess high thermal and chemical stability. The pigments were also found to be appropriate candidates for the coloration of polymer substrates. Thus, the present environmental friendly pigment powders may find potential alternative to the classical toxic inorganic pigments for various applications.
Social implications
There is a strong incentive to design new colorants based on inorganic materials to substitute for industrial pigments that are based on heavy elements hazardous to health and the environment. However, several industrial yellow pigments such as cadmium yellow (CdS), chrome yellow (PbCrO4) and nickel titanium yellow (TiO2-NiO-Sb2O3) contain the harmful elements (e.g. Cd, Pb, Cr and Sb) for the human body as well as the environment. The designed pigments consist of non-toxic elements and were further found to possess high thermal and chemical stability. The pigments were also found to be appropriate candidates for the coloration of polymer substrates. Thus, the present environmental friendly pigment powders may find potential alternative to the classical toxic inorganic pigments for various applications.
Originality/value
There is a strong incentive to design new colorants based on inorganic materials to substitute for industrial pigments that are based on heavy elements hazardous to health and the environment. However, several industrial yellow pigments such as cadmium yellow (CdS), chrome yellow (PbCrO4) and nickel titanium yellow (TiO2-NiO-Sb2O3) contain the harmful elements (e.g. Cd, Pb, Cr and Sb) for the human body as well as the environment. So, the authors have developed new class of inorganic pigments that are both non-toxic and environmentally unimpeachable, while preserving or even exceeding the optical, thermal and chemical characteristics of the existing commercial pigments. The developed colorants find practical applications in polymer matrix like PMMA.
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Recent years have seen a significant increase in the use of inkjet technology for printing on textile fabrics. Typical inkjet printed textile products included curtains, large…
Abstract
Recent years have seen a significant increase in the use of inkjet technology for printing on textile fabrics. Typical inkjet printed textile products included curtains, large advertising posters, flags and banners. As a result of the need for such inkjet printed products to have a greater durability, especially for outdoor applications, inks containing pigments as the colourants are gaining more interests. However, pigments may give rise to logistical problems in terms of their dispersion stability within the ink formulation, consequently blocking the nozzles within the inkjet print head. This paper reports methods for the preparation of pigment dispersions and of inkjet printing ink formulations and the methods for the evaluation of the suitability of pigmented ink formulations for jet printing on textile materials. In particular, the suitability of three magenta pigments for inkjet inks were assessed and reported.
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Abstract
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Benjamin Tawiah, Liping Zhang, Anli Tian and Shai Shao Fu
The purpose of this paper is to colour aluminium pigment to the highest chroma using SiO2 and organic silane with dichlorotriazine reactive dye and investigate its reaction…
Abstract
Purpose
The purpose of this paper is to colour aluminium pigment to the highest chroma using SiO2 and organic silane with dichlorotriazine reactive dye and investigate its reaction mechanism, chemical stability and thermal properties to improve its applicability in surface coatings.
Design/methodology/approach
Aluminium pigment was encapsulated by the catalysed sol-gel method using SiO2, followed by modification with γ-glycidoxypropyltrimethoxysilane (GPTMS). Purified reactive dye (1-Amino-4-[3-(4,6-dichlorotriazin-2-ylamino)-4-sulfophenylamino]anthraquinone-2-sulfonic acid (X-BR)) was covalently immobilized onto modified SiO2 to obtain coloured aluminium pigment. The reaction mechanism, chemical stability and thermophysical properties were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope and thermogravimetric analyses (TGA).
Findings
The results showed that X-BR was covalently attached to modified Al/SiO2 with maximum colour grafting of 95 per cent when the dosage of GPTMS and X-BR per weight of modified Al/SiO2 was 25 and 15 per cent, respectively, at pH 8.5 and a temperature of 40°C. The coloured aluminium pigment had good chemical stability with excellent anti-migration properties in many solvents.
Research limitations/implications
The organic silane used required a careful control of pH to ensure maximum colour grafting efficiency meanwhile other silanes with amine groups could also be used effectively with different kinds of colorants besides reactive dyes.
Practical implications
The method used is less cumbersome and provides a simple route to preparing coloured aluminium pigment.
Originality/value
The use of organic-inorganic SiO2/γ- GPTMS with purified reactive dye to covalently colour aluminium pigment to the highest chroma is novel and will help advance the frontiers of knowledge on coloration of aluminium pigments.
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Xinxin Fu, Yanjun Chen, Minggang Sun and Tengjiang Yu
The service performance for colored asphalt pavement is inevitably affected by the addition of different colorants, especially the challenge of low temperature environment in cold…
Abstract
Purpose
The service performance for colored asphalt pavement is inevitably affected by the addition of different colorants, especially the challenge of low temperature environment in cold regions. Therefore, the purpose of study is to explore the effects of different colorants on the service performance for colored asphalt pavement and to provide a foundation for improving the applicability of colored asphalt pavement in cold regions.
Design/methodology/approach
In the study, three kinds of colorants (iron oxide red, iron oxide yellow, iron oxide green) were used to compare the influence of different colorants amounts and different colorants kinds on the service performance for colored asphalt pavement in cold regions. According to the characteristics of low temperature in cold regions, the effects of different colorants on the low temperature performance for colored asphalt pavement were studied.
Findings
The study shows that different colorants have different effects on the service performance of colored asphalt pavement. The high temperature performance increases with the increase of the colorants amount, but the low temperature performance is opposite. Additionally, the yellow colored asphalt pavement has more advantages of low temperature adaptation than the red and green colored asphalt pavement.
Originality/value
The study results provide a certain theoretical foundation for the application of colored asphalt pavement in cold regions and have certain value and significance for the further development of colored asphalt pavement.
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Monthon Nakpathom, Buppha Somboon, Nootsara Narumol and Rattanaphol Mongkholrattanasit
The present study aims to focus on the feasibility of using an aqueous extract from the fruit shell of Camellia oleifera Abel as a source of natural colourant in printing-paste…
Abstract
Purpose
The present study aims to focus on the feasibility of using an aqueous extract from the fruit shell of Camellia oleifera Abel as a source of natural colourant in printing-paste preparation for pigment printing of cotton fabric. The effects of pre- and post-mordanting with three common metallic mordants, that is AlK(SO4)2, CuSO4 and FeSO4 on colour yield and colour fastness properties are also investigated.
Design/methodology/approach
The printing paste was prepared by mixing the concentrated Camellia oleifera Abel fruit shell extract solution with commercially available synthetic thickener and binder. The fabric sample was printed with the prepared printing paste using a flat-screen printing technique. To determine the effects of pre- and post-mordanting, AlK(SO4)2, CuSO4 and FeSO4 mordant aqueous solutions with various concentrations were applied using the pad-dry technique. Comparisons between printing with and without mordants were evaluated in terms of colour strength (K/S values) and colour fastness to washing, light, crocking and perspiration.
Findings
Without the mordants, the printed fabric had a yellowish brown shade with acceptable colour fastness properties, that is fair to good wash fastness, moderate light fastness, good to very good crocking fastness and fair to good perspiration fastness. The use of mordants, especially CuSO4 and FeSO4, not only enhanced colour strength but also imparted different colours to the fabric. Compared to the unmordanted fabrics, colour fastness properties were mostly comparable or improved in the mordanted fabrics depending on the type and concentration of mordants.
Research limitations/implications
Although in the case of CuSO4 the light fastness was increased to a good to very good level, it is recommended that the final print be produced with a concentration of less than 0.125 gL−1 to yield the print with the residual amount of Cu metal under the limit, that is less than 50 ppm as regulated by the Oeko-Tex® standard.
Practical implications
The obtained prints from Camellia oleifera Abel fruit shell extract provided shades with satisfactory colour fastness to washing, light, crocking and perspiration. The extract from Camellia oleifera Abel fruit shell has the potential to be used as an alternative to synthetic dye in the textile industry.
Originality/value
The use of Camellia oleifera Abel fruit shells, which are considered as abundant byproducts of tea seed oil production, as natural colouring agents for pigment printing of cotton fabric has been reported for the first time. It will minimise the environmental impact of this waste and create more valuable textile products.
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Amrita Poonia and Surabhi Pandey
Whey is a by-product of paneer, cheese and casein industry and considered as a dairy waste. Worldwide, approximately 180–1,900 million tons of whey is produced annually. Whey is…
Abstract
Purpose
Whey is a by-product of paneer, cheese and casein industry and considered as a dairy waste. Worldwide, approximately 180–1,900 million tons of whey is produced annually. Whey is classified as a high pollutant due to its organic matter level. Owing to its high chemical oxygen demand and biological oxygen demand, it is a big threat to the environment. Whey contains 4.5%–5.0% lactose, 0.6%–0.7% protein, 0.4%–0.5% lipids, vitamins and minerals. Due to its high nutritional profile, it is a good substrate for the microorganisms for production of natural pigments. The purpose of this paper is to review the utilization of low cost substrate (whey) for production of various types of pigments and their applications in different sectors.
Design/methodology/approach
The databases for the search included: Scopus, PubMed, Science Direct, Web of Science, Research gate and Google. The main search was directed towards different types of natural pigments, stability, technologies for enhancing their production and contribution towards circular economy. Approximately 100 research papers were initially screened. A global search was conducted about natural pigments. Research articles, review papers, books, articles in press and book chapters were the type of search for writing this review paper.
Findings
Production of natural pigments using whey and their addition in food products not only improves the colour of food but also enhances the antioxidant properties of food products, helping the health benefits by chelating free radicals from the body. The sustainable use of whey for production of natural pigments can improve the bio-based economy of different industries and thereof the national economy.
Originality/value
Efficient utilization of whey can bring a lot more opportunities for production of natural pigments in a sustainable manner. The sustainable approach and circular economy concepts will benefit the dependent industries and health conscious consumers. The potential uses of whey for the production of natural pigments using diverse organisms are highlighted in this paper.
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