Pigment & Resin Technology最新文献

Purpose

The precise and sensitive methods for authentication and differentiation of natural and synthetic indigo dyes are required for assurance of textile safety and public health. This study aims to develop a fast and simple method to distinguish natural indigo from synthetic one.

Design/methodology/approach

A static headspace gas chromatography-mass spectrometry (GC-MS) method was developed for identification of natural and synthetic indigo samples. Natural indigo samples prepared from three different plants and synthetic indigo samples from three famous manufacturers in China, were involved in this study, along with some nonindigo blue samples (such as direct blue, active blue and neutral blue). The yarns and fabrics dyed with natural and synthetic indigo were also analyzed by the GC-MS method.

Findings

High levels of aniline (21.87%–71.59%) or N-methylaniline (25.26%–38.73%) were detected only in synthetic indigo samples (1 g) using the static headspace GC-MS method. The yarns and fabrics dyed with the synthetic indigo were also detected with residual aniline (0.47%–14.86%) or N-methylaniline (6.59%–40.93%).

Originality/value

The results clearly demonstrated that aniline or N-methylaniline can be used a diagnostic marker for distinguishing natural indigo from synthetic indigo. The proposed static headspace GC-MS method is a rapid, simple and convenient approach for differentiation of natural and synthetic indigo, as well as for the yarns and fabrics dyed with synthetic indigo.

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.

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.

Purpose

The purpose of this study was to assess the repercussions of eucalyptus bark and tea leaf extract as natural dyes and antibacterial agents for jute–cotton union fabric.

Design/methodology/approach

The dye was collected from the eucalyptus tree’s bark and tea leaves by the aqueous extraction method. The fabric was dyed with potassium alum mordant, using pre-mordanting, post-mordanting and meta-mordanting methods. Examine the color performance analyzed the K/S, L*, a*, b*; fastness to washing using standard test method ISO 105 C06 A2S, rubbing fastness was performed by Crock meter using AATCC 115. The dyed fabrics were characterized by Fourier transform infrared radiation for the existence of various functional groups. Also, antimicrobial activity testing was done by the agar diffusion method (AATCC method SN 195 920) where Escherichia coli and Staphylococcus aureus were used.

Findings

The extracted dye tea leaves meta-mordant dyed samples were determined to have the strongest relative color. Fabrics pre-mordanted and post-mordanted with extracted eucalyptus and extracted tea dye produced the same outcome, which was excellent for wash fastness to staining and very good for wash fastness to fading. For both eucalyptus bark and tea, rubbing fastness on the pre-mordanted fabric produced very positive results. In mordanted colored fabric, significant antibacterial activity was discovered against S. aureus and E. coli.

Originality/value

This study demonstrates that the eucalyptus bark and tea leaves extract encompasses a solid antimicrobial action with amazing coloring execution for jute–cotton union fabric.

Purpose

The purpose of this paper is to introduce four new organic dyes based on naphthalimide for dye-sensitized solar cells (DSSCs).

Design/methodology/approach

Four new dyes based on naphthalimide with substitutions of amine and acetylamine in position C4 were designed in conjugation with substituted carbazole as donor–acceptor (D-A) architecture. The absorption and emission characteristics of the prepared dyes were evaluated in H₂O, DMF and their mixture (DMF:H₂O = 1:1). The feasibility of electron transfer in the DSSCs structure and energy levels were evaluated using electrochemical and density functional theory, which confirm the use of dyes in the DSSCs structure. The DSSCs were prepared using an individual strategy and their optical properties were investigated under the light of AM 1.5.

Findings

The prepared dyes exhibit orange color with strong emission at λem = 530–570 nm due to charge transfer with a positive solvatochromic effect. The efficiency of DSSCs based on Dye1-4 1 is: 3.69%, 3.71%, 4.69% and 4.76%. Therefore, the power efficiency increases by about 29 % in the presence of acetylamine group.

Practical implications

The design of new structures of organic dyes should be accompanied by the development of optical and electrical properties. In other words, in addition to the continuous production of electrons, efficient dyes must also be resistant to light to increase the life of the device.

Social implications

Organic dyes play a key role in the production of electrons in the DSSCs structure. The engineering of these structures and the introduction of widely used but low cost types can play an important role in the development of clean energy production.

Originality/value

The application of organic dyes based on naphthalimide was evaluated in the DSSCs structure and its photovoltaic properties were investigated.

Purpose

This paper aims to focus on the aqueous extraction of natural dye from haematoxylum campechianum L. bark for finishing the bio-mordant cotton fabrics producing value-added, environment-friendly textile products, for biomedical applications.

Design/methodology/approach

The study focuses on the creation of eco-friendly bio-mordant cotton fabric using gallic acid and gelatin, Al³⁺ and Fe²⁺ salts and metal mordant. The optimal pH for extraction, structural characterization and phytochemical analysis of the extracted dye were estimated using UV-visible spectrophotometer, FTIR and qualitative analysis. Variations in electrolyte concentration and pH medium were also considered. The study also examines build-up properties, colorimetric values and fastness characteristics of the colored fabrics.

Findings

All the dyed fabrics exhibit very good to excellent in terms of antimicrobial resistance against S. aureus and C. allbicans.

Practical implications

Pre-mordant cotton fabrics with Fe²⁺ and a combination of metal and bio-mordant show higher antibacterial resistance against P. aerugionsa. Further, bio-mordant and a combination of both mordant exhibit excellent UV protection and antioxidant activity performance compared to that of undyed fabrics.

Originality/value

This work opens up a huge potential for producing healthy bioactive-colored fabrics used in medical textiles and other usages.

Purpose

In the textile dyeing industry, the foam dyeing has been recognized as a significantly sustainable alternative for the cotton fabrics. However, this efficient technology undergoes the many issues related to the foam generation, foam optimization and the required performance of the resultant fabrics. The purpose of this paper is to address these issues through the development and optimization of the novel reactive foam dyeing recipes for the cotton fabrics.

Design/methodology/approach

The foam dyeing recipes were generated and optimized using the different stabilizers, foaming agents and three primary colors of reactive dyes. The different recipes were applied onto the cotton fabric using laboratory scale foam coating machine. The performance of the foam coated and padded fabrics was evaluated using different criteria including the shade depth, rubbing fastness, air permeability, washing fastness, perspiration fastness, light fastness and tear strength. Then, a complex decision-making approach, namely, analytic hierarchy process (AHP), was applied for the ranking of the key recipes based on the main criteria.

Findings

The newly optimized foam dyeing recipes were found very competitive with the conventional pad dyeing process with respect to the shade-depth and the other performance properties. The optimization of foaming parameters and addition of stabilizers have advanced the foam dyeing process, which would accelerate the implementation of foam dyeing methods in the textile industry. Furthermore, significant water and energy savings would be achieved as compared to the conventional foam dyeing. AHP model offered a comprehensive and rational way to identify the most important recipes amongst the selected recipes.

Originality/value

In this research, novel foam dyeing recipes have been developed for the cotton fabrics through the optimization of the different stabilizers, foaming agents and the three primary colors of reactive dyes. Until now, the exiting literature has not reported the combination of these stabilizers with the different foaming agents and three primary reactive dyes for the improvement of sustainable foam cotton dyeing process.

Purpose

The traditional vinyl ester of neodecanoic acid-vinyl acetate (VeoVa10-VAc) copolymer latex is a linear structure with poor film formation, thus causing solvent resistance and wear resistance of the latex film to be poor. This study aims to investigate the use of cross-linkers in emulsion polymerization to modify the latex. During the course of film formation, the reactive functional groups react to form cross-linkage. The network structure can effectively improve the compactness of the resin, thereby greatly improving the water resistance, solvent resistance and heat resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. Thus, the drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored.

Design/methodology/approach

The cross-linked VAc-VeoVa10 latex has been synthesized with the reactive surfactants, in which VAc and VeoVa10 are used as the main monomers and ethylene glycol dimethacrylate (EGDMA) was used as the cross-linked monomer. Potassium persulfate (KPS) and mixed surfactants of alkyl allyl polyoxyethylene ether ammonium sulfate (JS-20) and allyl nonyl phenol polyoxyethylene ether (ANPEO-10) were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy. The latex films were tested by thermogravimetric analysis, differential scanning calorimetry and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.

Findings

The factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.

Practical implications

The resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.

Originality/value

The modification of poly (VAc-VeoVa10) by reactive emulsifier and cross-linker is seldom reported. In this study, the cross-linked poly (VAC-VeoVa) latex is prepared through the reactive surfactants, with VAc and VeoVa10 used as the main monomers and EGDMA used as the cross-linked monomer. KPS and mixed surfactants of JS-20 and ANPEO-10 are used as the initiator and emulsifier, respectively.

Purpose

This study aims to investigate the influences of polyester fabric layers on the mechanical properties of SBR and devulcanized waste rubber composite materials, as well as the effect of gamma irradiation dose.

Design/methodology/approach

The devulcanized waste rubbers (DWR) were carried out by different methods. First, chemically, by two different reclaiming agents such as tetramethylthiuram disulfide (TMTD) and 2-mercapto benzothiazole disulfide (MBTS). Secondary by a physical method like microwave (MW). The devulcanized rubbers were mixed with virgin styrene butadiene rubber (SBR) in different ratios, as follows: SBR-DWR (TMTD) 50 / 50, SBR-DWR (MBTS) 80 / 20 and SBR-DWR (MW) 80 / 20. A series of sandwich polyester tire cord fabrics were used as reinforcement for making SBR and devulcanized waste rubber composite materials and molded on a hot press into rubber sheet films, then subjected to gamma radiation at different doses ranging from 100 up to 200 kGy.

Findings

The experimental results indicate that increasing the layer number improves the mechanical properties of composites. The tensile strength, tearing, hardness and elastic modulus of the rubber composites increased with the rise of the fiber layers and by increasing the irradiation dose up to 200 kGy. The reclaiming agent TMTD gave the best results for mechanical properties, followed by MW and then MBTS.

Originality/value

This phenomenon can be detailed based on the fact that when the fiber-reinforced composites are subjected to loading, the fibers act as load carriers, depending on the population and orientation of the fibers. Also, scanning electron microscopy (SEM) reveals that adhesion was caused by tire cord fabrics and rubber blend matrix.

Purpose

This paper aims to prepare Poly(Styrene-Butyl acrylate-Methacrylic acid) @Poly Gallic acid-Fe³⁺ photonic crystal composite inks [P(St-BA-MAA)@PGA-Fe³⁺ PCCI, @ means the PGA-Fe³⁺ is loaded on the microspheres] and construct noniridescent structural colors on fabric substrates, with the goal of improving the visibility of structural colors.

Design/methodology/approach

P(St-BA-MAA)@PGA-Fe³⁺ PCCI were prepared by coating P(St-BA-MAA) microspheres with a metal-polyphenol network formed by gallic acid (GA, C₇H₆O₅) and Fe³⁺. The assembly effects of the inks were explored under different conditions, including pH, temperature, concentration and surface tension. The optimal self-assembly conditions of the inks were determined using the controlled variable method.

Findings

The results demonstrated the successful preparation of P(St-BA-MAA)@PGA-Fe³⁺ PCCI. The metal polyphenol network film composed of GA and Fe³⁺ was successfully coated on the surface of P(St-BA-MAA) seed microspheres. The assembly mechanism of the inks was investigated, indicating that at a diethylene glycol (DEG, C₄H₁₀O₃) concentration of 0.3 wt% and pH of 7, bright noniridescent structural colors could be formed on fabric surfaces after self-assembly by PCCI at 60 °C for 10 min. Furthermore, the mechanical fastness of the structural colors was enhanced due to the adherence of the soft shell composed of P(St-BA-MAA) and GA.

Originality/value

Utilizing a cost-effective approach and a diverse array of readily available raw materials, we have successfully prepared P(St-BA-MAA)@PGA-Fe³⁺ PCCI, which boasts superior performance and offers fabrics a range of unique coloring styles. This innovation paves the way for potential applications of structural colors in practical production, thereby broadening their realm of utility.