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1 – 10 of 150Xuemei Wang, Jixiang He, Yue Ma, Hao Wang, Dehong Ma, Dongdong Zhang and Hudie Zhao
The purpose of this study is to evaluate the tannase-assisted extraction of tea stem pigment from waste tea stem, after which the stability of the purified pigment was determined…
Abstract
Purpose
The purpose of this study is to evaluate the tannase-assisted extraction of tea stem pigment from waste tea stem, after which the stability of the purified pigment was determined and analyzed.
Design/methodology/approach
The extracting process was optimized using the response surface methodology (RSM) approach. Material-liquid ratio, temperature and time were chosen as variables and the absorbance as a response. The stability of the tea stem pigment at the different conditions was tested and analyzed.
Findings
The optimized extraction technology was as follows: material-liquid ratio 1:20 g/ml, temperature 50°C and time 60 min. The stability test results showed that tea stem pigment was sensitive to oxidants, but the reducing agents did not affect it. The tea stem pigment was unstable under strong acid and strong alkali and was most stable at pH 6. The light stability was poor. Tea stem pigment would form flocculent precipitation under the action of Fe2+ or Fe3+ and be relatively stable in Cu2+ and Na2+ solutions. The tea stem pigment was relatively stable at 60°C and below.
Originality/value
No comprehensive and systematic study reports have been conducted on the extraction of pigment from discarded tea stem, and researchers have not used statistical analysis to optimize the process of tannase-assisted tea stem pigment extraction using RSM. Additionally, there is a lack of special reports on the systematic study of the stability of pigment extracted from tea stem.
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Xuening Fei, Yuanyuan Li, Shuai Li, Lingyun Cao, Dajie Xing, Bingyang Cheng, Meitong Li and Hongbin Zhao
This study aims to realize the multipurpose use of inorganic materials in adsorption treatment of pigment wastewater and preparation of core-modified Color Index Pigment Red 57:1…
Abstract
Purpose
This study aims to realize the multipurpose use of inorganic materials in adsorption treatment of pigment wastewater and preparation of core-modified Color Index Pigment Red 57:1 (C.I. Pigment Red 57:1, PR 57:1).
Design/methodology/approach
In this paper, the inorganic materials (sepiolite and SiO2·nH2O) were used in both PR 57:1 production wastewater treatment and its core-modification. The inorganic material firstly adsorbed 3-hydroxy-2-naphthoic acid (bon acid) in the pigment wastewater to reduce chemical oxygen demand. Then, the inorganic material adsorbed with bon acid was reused to prepare core-modified PR 57:1.
Findings
In the pigment wastewater adsorption experiment, it was found that under pH = 3, the adsorption percentage of bon acid by inorganic material can reached up to 46.00%. The pigment characterization results showed that the core-modified PR 57:1 had a core-shell structure. Under UV light irradiation for 1 h, the core-modified PR 57:1 prepared with sepiolite and SiO2·nH2O showed total color difference ΔE value of 1.43 and 2.05, respectively, which was lower than that of unmodified PR 57:1 (ΔE = 2.89). In addition, the transmittance of pigment water suspension test results showed that the core-modified PR 57:1 showed better water dispersibility.
Originality/value
This paper attempts to develop a synergistic strategy based on the multipurpose use of inorganic materials in adsorption treatment of pigment wastewater and preparation of core-modified PR 57:1.
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This study aims to explore the synthesis, characteristics and utilization of polymer composites integrated with cutting-edge pigments.
Abstract
Purpose
This study aims to explore the synthesis, characteristics and utilization of polymer composites integrated with cutting-edge pigments.
Design/methodology/approach
The incorporation of advanced pigments introduces functionalities such as enhanced mechanical strength, thermal stability, ultraviolet resistance and color stability, thus extending the range of applications in diverse fields including automotive, aerospace, electronics and construction.
Findings
This review discusses the mechanisms underlying the property enhancements achieved through the incorporation of advanced pigments and highlights recent developments in the field.
Originality/value
Polymer composites incorporating advanced pigments have garnered significant attention in recent years because of their potential to enhance various material properties and broaden their applications. This paper explores the fabrication methods of polymer composites reinforced with organic/inorganic advanced pigments in brief along with their characteristics and applications.
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Xinrui Wang, Xiaomeng Hu, Xiangnan Feng, Xinyu Han, Qi Liu and Yueqin Li
This study aims to produce composite pigments, including SHS/ZnAl-LDHs, IDS/ZnAl-LDHs and SNND/ZnAl-LDHs, with improved coloration, enhanced photostability and thermostability and…
Abstract
Purpose
This study aims to produce composite pigments, including SHS/ZnAl-LDHs, IDS/ZnAl-LDHs and SNND/ZnAl-LDHs, with improved coloration, enhanced photostability and thermostability and biocompatibility.
Design/methodology/approach
The chemical structures of the composite pigments were characterized by X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy. Photostability and thermal stability were assessed using ultraviolet-visible spectroscopy and colorimetry. The coverage of the dyes was determined through black-and-white tile testing, and specific RGB values were used to indicate color expressiveness. Finally, a four-color eyeshadow was formulated, and safety tests were conducted via human patch test and cellular assays to confirm the safety and reliability of the samples.
Findings
The experimental results demonstrate an enhancement in the photo and thermal stability of the SHS/ZnAl-LDHs, IDS/ZnAl-LDHs and SNND/ZnAl-LDHs composites, along with their superior performance in terms of covering power and color saturation. These composite pigments also exhibit high safety, making them well-suited for cosmetic applications.
Practical implications
The composite pigments based on hydrotalcite can be used in the cosmetic industry without causing any harm to the environment and human health.
Originality/value
The addition of hydrotalcite enables better application of pigments in cosmetics.
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Malav R. Sanghvi, Karan W. Chugh and S.T. Mhaske
This study aims to synthesize Prussian blue {FeIII4[FeII(CN)6]3} pigment by reacting ferric chloride with different ferrocyanides through the same procedure. The influence of the…
Abstract
Purpose
This study aims to synthesize Prussian blue {FeIII4[FeII(CN)6]3} pigment by reacting ferric chloride with different ferrocyanides through the same procedure. The influence of the ferrocyanide used on resulting pigment properties is studied.
Design/methodology/approach
Prussian blue is commonly synthesized by direct or indirect methods, through iron salt and ferrocyanide/ferricyanide reactions. In this study, the direct, single-step process was pursued by dropwise addition of the ferrocyanide into ferric chloride (both as aqueous solutions). Two batches – (K-PB) and (Na-PB) – were prepared by using potassium ferrocyanide and sodium ferrocyanide, respectively. The development of pigment was confirmed by an identification test and characterized by spectroscopic techniques. Pigment properties were determined, and light fastness was observed for acrylic emulsion films incorporating dispersed pigment.
Findings
The two pigments differed mainly in elemental detection owing to the dissimilar ferrocyanide being used; IR spectroscopy where only (Na-PB) showed peaks indicating water molecules; and bleeding tendency where (K-PB) was water soluble whereas (Na-PB) was not. The pigment exhibited remarkable blue colour and good bleeding resistance in several solvents and showed no fading in 24 h of light exposure though oil absorption values were high.
Originality/value
This article is a comparative study of Prussian blue pigment properties obtained using different ferrocyanides. The dissimilarity in the extent of water solubility will influence potential applications as a colourant in paints and inks. K-PB would be advantageous in aqueous formulations to confer a blue colour without any dispersing aid but unfavourable in systems where other coats are water-based due to their bleeding tendency.
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Guillermo Monrós, Mario Llusar and José Antonio Badenes
The purpose of this study is the synthesis and characterization of a CMYK palette (cyan of Cr-BiVO4, magenta of Pr-CeO2, yellow of Bi-(Ce,Zr)O2 composite and black of YMnO3) as an…
Abstract
Purpose
The purpose of this study is the synthesis and characterization of a CMYK palette (cyan of Cr-BiVO4, magenta of Pr-CeO2, yellow of Bi-(Ce,Zr)O2 composite and black of YMnO3) as an eco-friendly polyfunctional palette that combines (a) high near-infrared reflectance (cool pigments) that allows moderate temperatures in indoor environments and the urban heat island effect; (b) photocatalytic activity for the degradation of organic contaminants of emerging concern of substrates in solution (such as Orange II or methylene blue) and gaseous (NOx and volatile organic compounds such as acetaldehyde or toluene); (c) X-ray radiation attenuators associated with bismuth ions; and (d) biocidal effect combined with co-doping with bactericidal agents.
Design/methodology/approach
Pigments were prepared by a solid-state reaction and characterized by X-ray diffraction, diffuse reflectance spectroscopy, photocatalytic activity over Orange II and scanning electron microscopy.
Findings
The behaviour of the proposed palette was compared to that of a commercial inkjet palette, and an improvement in all functionalities was observed.
Social implications
The functionalities of pigments allow the building envelope and indoor walls to exhibit temperature-moderating effects (with the additional effects of moderating global warming and increasing air conditioning efficiency), purification and disinfection of both indoor and outdoor air, and radiation attenuation.
Originality/value
The proposed palette and its polyfunctional characterization are novel.
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Lingyun Cao, Shuaibin Ren, ZhengHao Zhou, Xuening Fei and Changliang Huang
This study aims to fabricate a cool phthalocyanine green/TiO2 composite pigment (PGT) with high near-infrared (NIR) reflectance, good color performance and good heat-shielding…
Abstract
Purpose
This study aims to fabricate a cool phthalocyanine green/TiO2 composite pigment (PGT) with high near-infrared (NIR) reflectance, good color performance and good heat-shielding performance under sunlight and infrared irradiation.
Design/methodology/approach
With the help of anionic and cationic polyelectrolytes, the PGT composite pigment was prepared using a layer-by-layer assembly method under wet ball milling. Based on the light reflectance properties and color performance tested by ultraviolet-visible-NIR spectrophotometer and colorimeter, the preparation conditions were optimized and the properties of PGT pigment with different assembly layers (PGT-1, PGT-3, PGT-5 and PGT-7) were compared. In addition, their heat-shielding performance was evaluated and compared by temperature rise value for their coating under sunlight and infrared irradiation.
Findings
The PGT pigment had a core/shell structure, and the PG thickness increased with the self-assembly layers, which made the PGT-3 and PGT-7 pigment show higher color purity and saturation than PGT-1 pigment. In addition, the PGT-3 and PGT-7 pigment showed 11%–16% lower light reflectance in the visible region. However, their light reflectance in the NIR region was similar. Under infrared irradiation the PGT-5 and PGT-7 pigment coating showed 1.1°C–3.4°C and 1.3°C–4.7°C lower temperature rise value than PGT-1 pigment coating and physical mixture pigment coating, respectively. And under sunlight the PGT-3 pigment coating showed 1.5–2.6°C lower temperature rise value than the physical mixture pigment coating.
Originality/value
The layer-by-layer assembling makes the core/shell PGT composite pigment possess low visible light reflectance, high NIR reflectance and good heat-shielding performance.
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Pankaj Naharwal, Mahesh Meena, Charul Somani, Neetu Kumari and Dinesh Kumar Yadav
This paper aims to critically review the isolation and chemistry of plant pigments.
Abstract
Purpose
This paper aims to critically review the isolation and chemistry of plant pigments.
Design/methodology/approach
A literature survey from 1974 to 2022 was carried out and studied thoroughly. The authors reviewed literature in various areas such as isolation methods and catalytic properties of pigments.
Findings
With vast growing research in the field of catalytic activities of various pigments like chlorophyll, anthocyanin and flavonoids, there is still scope for further research for the pigments such as Lycopene, carotenoids and xanthophyll as there has not been any significant work in this area.
Research limitations/implications
Plant pigments may be used as an ecofriendly catalyst for chemical reactions.
Practical implications
One can get the direction of pigment research.
Social implications
Plant pigments are natural and ecofriendly catalyst which can reduce the pollution.
Originality/value
This is an original work. This paper precisely depicts the advantages as well as disadvantages of the isolation techniques of pigments. This study also presents the chemistry of plant pigments.
Graphical abstract
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Martina Glogar and Sanja Ercegovic Razic
In the field of research on the application of digital printing to textile materials, there are still many research issues that arise from the very demanding interaction of…
Abstract
Purpose
In the field of research on the application of digital printing to textile materials, there are still many research issues that arise from the very demanding interaction of digital printing technology and the complex, heterogeneous surface system of textile materials. This is precisely why the area of pre-treatment of textile materials is in need of research, and the purpose of this research was to establish the level of influence of physical and chemical activation of the textile surface with plasma and the possibility of improving the quality of the print and colour reproduction.
Design/methodology/approach
The paper deals with the possibility of applying argon and oxygen cold low-pressure plasma in the processing of cellulose knitted fabrics, with the aim of improving the quality of the print and colour reproduction in digital pigment inkjet printing. The selected raw material samples were 100% raw cotton and lyocell. After plasma treatment, the samples were printed by digital ink jet printing with water-based pigment printing ink. An analysis of the micromorphological structure of untreated and plasma-treated samples before and after printing was carried out, and a comparative analysis of the colour of the printed elements was carried out depending on the pre-treatment.
Findings
The conducted research showed a positive influence of plasma pre-treatment on the coverage of the fibre surface with pigments, the uniformity of pigment distribution along the fibre surface and the uniformity of the distribution of the polymeric binder layer. This has a positive effect on colour reproduction. Also, certain improvements in colourfastness to washing were obtained.
Research limitations/implications
Considering the complexity of the topic, although exhaustive, this research is not sufficient in itself, but opens up new questions and gives ideas for further research that must be carried out in this area.
Practical implications
Also, this kind of research contributes to the possibility of adopting the idea of industrial plasma transformation, as an ecologically sustainable functionalisation of textiles, which has not yet been established.
Originality/value
This research is certainly a contribution to the establishment of acceptable textile pre-treatment methods in the field of digital printing, as one of the key quality factors in digital textile printing (DTP). Considering the still large number of obstacles and unanswered questions encountered in the field of digital printing on textiles, this kind of research is a strong contribution to the understanding of the fundamental mechanisms of the complex interaction between printing ink and textile.
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Seda Aygül, Serkan Yılmazsönmez, Arzu Soyalp and Ayse Aytac
Titanium dioxide (TiO2) has high opacity, high brightness and whiteness, owing to its high refractive index value. It is mainly used in the coating industry and continuous efforts…
Abstract
Purpose
Titanium dioxide (TiO2) has high opacity, high brightness and whiteness, owing to its high refractive index value. It is mainly used in the coating industry and continuous efforts have been made to replace some of the TiO2 in paint with new pigments. This study aims to replace part of TiO2 pigment with various percentages of BaSO4, CaCO3 and kaolin in styrene butyl acrylate-based paint formulations, without changing the properties of paints using only titanium dioxide.
Design/methodology/approach
To determine the optimum use rate of new pigment mixing, opacity, gloss, scrub resistance and weather resistance properties have been investigated in the water-based paint formulation. The morphological properties of these samples were examined by scanning electron microscopy analysis.
Findings
In the total color change (ΔE) measurements, it was observed that the sample coded 85Ti/15Ba produced extremely similar results to the situation when TiO2 was used alone. It was seen that the best results were obtained when 85Ti/15Ba was used instead of TiO2.
Originality/value
Comparison research on the impact of replacing TiO2 with BaSO4, CaCO3 and kaolin on the performance characteristics of water-based styrene butyl acrylate-based paint formulations has not been done in the literature, according to the literature search.
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