Multifunctional Dyeing of Wool Fabrics Using Selenium Nanoparticles

This work aims to utilize selenium nanoparticles (Se-NPs) as a novel dyestuff, which endows wool fibers with an orange color because of their localized surface plasmon resonance. The color characteristics of dyed fibers were evaluated and analyzed. The color depth of the dyed fabrics under study was increased with the increase in Se content and dyeing temperature. The colored wool fabrics were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and an X-ray diffraction (XRD) analysis. The results indicated that spherical Se-NPs with a spherical shape were consistently deposited onto the surface of wool fibers with good distribution. In addition, the influence of high temperature on the color characteristics and imparted functionalities of the dyed fabrics were also investigated. The obtained results showed that the proposed dyeing process is highly durable to washing after 10 cycles of washes, and the acquired functionalities, mainly antimicrobial activity and UV-blocking properties, were only marginally affected, maintaining an excellent fastness property.

Trichromatic Vat Dyeing of Cationized Cotton

This article deals with cationization of cotton during mercerization and its effects on trichromatic vat dyeing. If cationization is carried out during the after-treatment, regardless of cotton pretreatment, the reaction takes place on the surface and blocks cellulose groups, subsequently resulting in uneven coloration. However, when cationization is carried out with an epihalohydrin during the mercerization process, new cellulose is formed in which the cationic compound is uniformly distributed and trapped between cellulose chains, resulting in uniform coloration after the dyeing process. The reaction time for the process during mercerization is 24 h, thus a more favorable process was researched. Based on electrokinetic analysis, it was found that 5 h was sufficient for the reaction with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC). The cationization of cotton contributed to the processes of vat dyeing. The change in charge upon cationization resulted in very high adsorption of vat-dye anions, indicating that ionic bonding occurred in addition to van der Waals forces. The color depth improved by more than 10 times. It should be emphasized that the colors with higher chroma and targeted color hue, especially in trichromatic dyeing, were obtained on cationized cotton, in contrast to standard cotton fabrics. The color differences obtained under the different light sources indicate the occurrence of metamerism. Considering the color fastness to laundering, vat-dyed cationized fabrics of all colors may be used in hospitals or other environments where high hygiene and oxidative bleaching are required.

Ultralow emission micro-printing process for PET fibers using liquid disperse dye

The commercial powder disperse dye used for printing polyester fabrics exhibits many environmentally-unfriendly properties, especially the associated high wastewater emission. In this study, three kinds of liquid disperse dyes (C.I. Disperse Blue 291:1, (L-DB); C.I. Disperse Red 179, (L-DR), and C.I. Disperse Orange 30, (L-DO)), two kinds of binders (A and/or B), and a micro-printing process, were applied to polyester fabric, with the goal of reducing freshwater consumption while maintaining color fastness. The influences of rheological and printing performance and color fastness were studied. Home-made liquid dyes of L-DB, L-DR and L-DO were found to exhibit higher color depth, excellent color fastness, and ultralow emission of wastewater and waste residual during the micro-printing process. The binder comprised of silicone-modified polyacrylate was observed to increase dye uptake, reduce dye sublimation, and improve color fastness. The liquid dyes of L-DB, L-DR and L-DO also exhibit stable and better rheological properties, which appeared to have little effect on the viscosity of printing pastes when compared with commercial powder disperse dye of Blue 3GFL (C.I. Disperse Blue 291:1), Red 2B (C.I. Disperse Red 179) and Yellow brown S-4RL (C.I. Disperse Orange 30), respectively. Results of this micro-printing process indicated that it is an environmentally clean production technology.

Effect of Pretreatments on Wettability and Dyeing Property of Cotton Fibers in an Environmentally Friendly Dyeing System

To investigate the influence of cotton wettability on its dyeing properties in a silicone non-aqueous dyeing system, alkali pretreatment was performed before dyeing. The dyeing properties and dyeing kinetics of reactive dyes in the non-aqueous system and a conventional dyeing system were compared. Alkali pretreatment significantly improved the wettability of cotton fiber by removing wax and pectin. The adsorption rate of dye increased with increased cotton fiber wettability using the non-aqueous system, while it barely changed using the conventional system. Pseudo-second-order kinetics fit well with dye adsorption for both systems. Dye fixation improved by 30% at a concentration of 2% owf, along with better levelness and color depth of the dyed cotton fiber, using the silicone non-aqueous system without salts and dispersants.

The effect of mordanting method on the absorption behavior of natural dyes

Purpose This work aims to study the effect of mordanting method as pre-mordanting (on-chrome), meta-mordanting (meta-chrome) and post-mordanting (after-chrome) on wool dyeing with madder natural dye without tannin and pomegranates peel, as a natural dye contains tannin. Design/methodology/approach The woolen yarn was dyed with madder and pomegranate peel natural dyes by three methods as pre-mordant, meta-mordant and pos-mordant. The color parameters and reflectance spectra of dyed samples were analyzed by using derivative spectroscopy and the principal component analysis (PCA) techniques. Findings The obtained results indicate that the color difference between the samples dyed with madder by pre-mordanting, and the samples dyed by other methods is more than the color difference between the samples dyed by meta-mordanting and post-mordanting. However, the color difference between samples dyed with pomegranate peel by pre-mordanting and meta-mordanting methods is less compared to other pairs. Also, analysis of reflectance spectra and color depth (K/S) values indicate that the color depth of dyed sample with madder by pre-mordanting method is more than other dyeing methods. But, the color depth of sample dyed with pomegranate peel by post-mordanting method is less compared to other methods. The analysis of first-, second-, third- and fourth-order derivatives of reflectance spectra and the study of the first, second, third and fourth PCs of reflectance spectra indicate that the reflectance of dyed samples with madder and pomegranates peel depends on the mordanting method. Originality/value Evaluation of the effect of mordanting method on color and reflectance of wool dyed with madder and pomegranates peel natural dyes using derivative spectroscopy and the PCA techniques

The Action Difference of Lasiodiplodia theobromae on Infecting and Dyeing Poplar Wood in Spatial Growth

Many factors affect the driving force of fungal growth and secretion. To compare the differences of Lasiodiplodia theobromae infected poplar wood, the changes of physical and chemical properties of vertically and horizontally infected poplar wood before and after dyeing were analyzed, and the infection characteristics were studied in this paper. The horizontal infection was more effective than the vertical infection in terms of infection depth, color depth, and microscopic hyphal invasion. The mycelium first intruded into the earlywood tissue and began to secrete a large amount of pigment after twenty days. The crystallinity of mycelium decreased slightly, and the difference in weight loss rate was negligible. The initial contact angle of the dyed specimen on the horizontal infection increased drastically in distilled water, but there was almost no difference between varnish and natural coating. The horizontal infection was more efficient than the vertical infection and had a higher color depth and a better induction effect, which is crucial in future microbial dyeing.

Fabrication and properties of polyaniline/ramie composite fabric based on in situ polymerization

Polyaniline (PANI) is one of the most important conducting polymer and has been widely used in various fields for its tunable electrical conductivity. In this manuscript, conductive polyaniline/ramie fabrics were developed by in situ polymerization and characterized. The effect of aniline content, polyetherimide (PEI) pretreatment, padding and the color depth (K/S value) on electrical resistivity was analyzed. The result showed that electrical conductivity was increased with the increase of aniline (ANI) contents. PEI pretreatment and padding method improved the conductivity of the fabric significantly. The result of K/S value was reversely consistent with the conductivity. Both scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis confirmed that polyaniline particles were successfully deposited on the surface of the ramie fabrics. Thermal degradation (TG) measurement showed that polyaniline (PANI) polymerization decreased the onset decomposition temperature. Mechanical measurement showed that pretreatment process reduced the tensile strength of conductive ramie fabrics by 30%. K/S value in full range showed that the color of PANI/ramie fabric was sensible to pH value. Contact angle (CA) measurement disclosed the conductive PANI/ramie fabric was hydrophobic and this hydrophobicity was stable to the change of pH value. The obtained PANI/ramie fabrics can be used as potential conductive multifunctional textiles.

Environmental Method for Preparation of Higher Color Strength Dyeing Cotton Fabrics with Colored Nanosilica Pigment

Dye wastewater into the water system would cause a severe threat to the natural environment. To reduce the dye discharge, it is highly essential to find a clean and green method to color cotton fabrics. Herein, this work has expediently designed the novel pigment with colored nanoparticles to dye cotton fabrics, which was based on the adsorption of dyes from dyes solution with the synthesis of worm-like hydrophilic porous silica (WHMS) and formed colored particles. It could be found that as-prepared WHMS exhibited with the larger surface area of 968.61 m2/g, the average size of 300 nm and the higher electronegativity on the surface of WHMS materials and could be favorable to capture dye to achieve the capacity above 500 mg/g for different cationic and reduce dyes discharge. The colored WHMS applied in dyeing cotton fabrics show the higher stability and stronger color strength by electrostatic attraction compared with original dyes, in which the mass of WHMS-dyes could be retained by above 80% in thermal decomposition, the color depth of WHMS-dyes dying fabrics increased by above1.2 times and the dye residues in the dyeing process were reduced. The high-quality dyeing fabrics can be obtained and nanospheres uniformly fixed on cotton fabrics through the binder to build a layer film, owing to its hydrophobicity and small sizes. The dyeing cotton fabrics exhibited good wet rubbing, washing fastness and hand feel. These results suggest that the WHMS-dyes can be suitable for cotton dyeing textiles as a sustainable coloring process.