Salt-free dyeability of thiourea grafted cotton fabric

In this study salt-free dyeing cotton fabric was achieved by grafting thiourea to cotton fibers, where the thiourea grafted cotton fabric (TUGCF) was prepared by epoxidizing cotton fibers with epichlorohydrin in water and subsequently grafting in aqueous solution of thiourea. Fourier transform infrared spectra (FTIR) and XPS of the TUGCF indicated that a great amount of epoxy groups from the epoxidized cotton fibers reacted with amino groups from thiourea. The TUGCF fabric prepared at the optimum condition and subsequently dyed with reactive dyes in the absence of salt displayed significantly enhanced color strength, showing better dyeing properties when compared with the untreated cotton fabric dyed with conventional methods, in terms of washing fastness, rubbing fastness, and levelness. It was found that the dyeing performance of Reactive Red B-3BF followed a Langmuir-type adsorption curve when used to salt-free dye the TUGCF.     

Dyeing properties and antimicrobial activity of silk fabric with extract of unripe Citrus Unshiu fruits

This study was carried out to optimize dyeing conditions of unripe Citrus Unshiu extract on silk fabric and to evaluate antimicrobial activity of the dyed fabric for its potential use as a functional natural dye. Unripe fruits of Citrus Unshiu in Jeju Island, Korea, extracted in 80 % Ethanol solution to final solid dye powder were dyed on silk fabric under a variety of conditions such as dye bath concentrations, temperature, and dyeing duration together with mordanting. Dyeing fastness properties to washing, rubbing, perspiration, and light were tested and the antimicrobial activities of the dyed fabric against Staphylococcus aureus and Klebsiella pneumoniae were investigated quantitatively. As results, the fabric showed the maximum dye uptake (K/S) under the conditions of 80 °C for temperature, 30 min for duration, and 600 % (o.w.f.) for dye concentration. Both pre- and post-mordanting seemed not to be effective on increasing K/S values of the dyed silk fabrics under the optimum dyeing conditions. Fastness ratings to washing, rubbing, and perspiration were all very good (4–5 grades) for both 300 and 600 % dyed silk fabrics. Excellent antimicrobial activities over 99 % reduction rate against two both bacteria were exhibited for all of dyed fabrics undergone more than 300 % of dye concentration. From these results, it was concluded that the dye concentration of 300 % of unripe Citrus Unshiu could be employed to produce antimicrobial silk fabric. Furthermore, to get more saturated shades on the fabric by the citrus, higher dye concentration such as 600 % was available as well.     

Dyeing characteristics of Nylon,cotton and N/C mixture fabrics with reactive-disperse dyes containing a sulphatoethylsulphone group

The dyeing and color fastness properties of three reactive-disperse dyes containing a sulphatoethylsulphone group on Nylon, cotton and N/C mixture fabrics were examined. Reduction-clearing was more effective in removing the unfixed dyes than soaping since the reactive-disperse dye became hydrophobic during dyeing process. Nylon was dyed well with three reactive-disperse dyes at pH 5∼8 and difference in chemical structure between dyes did not affect the final color strength of the dyed Nylon fiber, but their build-up properties on Nylon were not so good. The color strength of the dyed cotton was not as high as that of Nylon. The color strength of cotton increased by lowering dyeing temperature when the reactive-disperse dyes having hydroxy group were used. Nylon absorbed more dye molecules than cotton in simultaneous dyeing, the color difference between Nylon and cotton could be reduced as the dyeing temperature decreased. N/C mixture fabric was dyed well at 60 °C with the reactive-disperse dyes having hydroxyl group when applied at pH 7 and 60 °C, and their build-up properties were good. It was also found that washing fastness and rubbing fastness of dyed Nylon, cotton and N/C fabrics with the reactive-disperse dyes were excellent, while light fastness was moderate.     

Dyeing of modified acrylic fibers with curcumin and madder natural dyes

Hydrophobic fibers are highly crysta lline and non-polar polymers hence pose a big problem for dyers. Modified acrylic fiber containing different amounts of amidoxime groups as a function of the nitrogen content was obtained and dyed with curcumin and madder natural dyes. The dyeing parameters, such as dye concentration, dye bath pH, salt concentration, temperature, and time and the effect of alum and ferrous sulfate used as mordants were investigated. Compared with the dyeings obtained from modified acrylics, those of blank samples appeared less in color strength values. The color strength was proportional to the nitrogen content of the sample and the maximum value was obtained at pH 2 and pH 5 using madder and curcumin, respectively. The fixation of the dye molecules to the modified acrylic fibers was investigated to show mainly ionic and physical bonds. The washing, perspiration, and rubbing fastness properties for the dyed samples were enhanced by application of alum. The light fastness ratings were also improved using ferrous sulfate especially for the case of the samples dyed with madder.     

Sonicator dyeing of natural polymers with <Emphasis Type="Italic">Symplocos spicata</Emphasis> by metal chelation

Symplocos spicata (local name: Dom sheng) belonging to Family Symplococeae produces yellowish brown natural dye which has been used for dyeing textiles since ancient times by the Monpas tribe of Arunachal Pradesh. Symplocos spicata (Dom Sheng) was found in the Lumla area of Tawang district. Leaves of the plant are used by the Monpas and Tibetans for extraction of dye. Innovative sonicator dyeing with S. spicata showed that pretreatment with 2–4% metal mordant of the weight of the fabric is optimum showing very good fastness properties for dyed natural polymers such as cotton, wool, and silk. CIELab and K/S of the dyed fabrics were also evaluated. The superiority of sonicator dyeing over conventional dyeing has been established through this study.     

Dyeing of meta-aramid fibers with disperse dyes in supercritical carbon dioxide

Dyeing characteristics of meta-aramid fibers were investigated in supercritical carbon dioxide by employing three disperse dyes and a carrier. The effects of dyeing temperature, pressure, time, dye concentration, CO₂ flow, and carrier concentration on dyeing properties were investigated. The results showed that meta-aramid fiber could be dyed in supercritical carbon dioxide. Its color depth was improved with increasing dyeing temperature, pressure, time, dye concentration, CO₂ flow, and carrier concentration. Moreover, the color depth could be significantly improved by adding the carrier. The dyeing procedure of supercritical carbon dioxide fluid did not influence the chemical structure and antistatic properties of the meta-aramid fiber. The maximum decomposition temperature and breaking strength of the dyed meta-aramid fiber are slightly increased. The dyed meta-aramid fiber in supercritical carbon dioxide had good fastness, which was rated at 4–5.     

Modification of polypropylene fibers by electron beam irradiation. I. Evaluation of dyeing properties using cationic dyes

The dyeing properties of hydrophobic polypropylene fibers using cationic dyes were investigated to improve dyeability by electron beam irradiation and sulfonic acid incorporation. The color strength of polypropylene fibers after irradiation was examined according to the dyeing conditions including the pH of the dyebath, absorbed doses, and the introduction of a functional group to the fiber substrate. The best dyeing result was obtained when polypropylene fibers incorporated by sulfonic acid group after electron beam irradiation were dyed with cationic dyes at alkaline conditions and 30∼75 kGy irradiation ranges.     

Dyeing and fastness properties of a reactive disperse dye on PET, nylon, silk and N/P fabrics

Dyeing and color fastness properties of a reactive disperse dye containing an acetoxyethylsulphone group on PET, Nylon, silk and N/P fabrics were examined. The reactive disperse dye exhibited almost the same dyeing properties on PET fabric as a conventional disperse dye except the level of dye uptake. The most appropriate pH and dyeing temperature for the dyeing of Nylon fabric were 7 and 100°C respectively. The build-up on Nylon fabric was good and various color fastnesses were good to excellent due to the formation of the covalent bond. Application of the reactive disperse dye on silk fabric at pH 9 and 80°C yielded optimum color strength. The rate of dyeing on Nylon fabric was faster than that on PET fabric when both fabrics were dyed simultaneously in a dye bath, accordingly color strength of the dyed Nylon was higher. The reactive disperse dye can be applied for one-step and one-bath dyeing of N/P mixture fabric with good color fastness.     

Effect of chelating agent in disperse dye dyeing on polyester fabric

In this study, mild acid based chelating agents (glycolic acid, gluconic acid, ethylenediaminetetraacetic acid, and citric acid) were used for the dyeing of polyester fabrics with metal sensitive disperse dye in closed dyeing process. The chelating and pH adjustment efficiencies were compared in disperse dyeing condition. In the comparative analysis with different chelating agents, glycolic acid showed a higher chelation efficiency and consequently showed higher dye bath exhaustion and color strength. Slight differences in the color fastness of the dyed samples obtained by employing four different chelating agents were observed.     

Dyeing of cotton and silk yarn with the extracted dye from the fruit hulls of mangosteen,<Emphasis Type="Italic">Garcinia mangostana</Emphasis> linn

The extracted dye from the dried fruit hulls of mangosteen was used as a natural dye for the dyeing of cotton and silk yarn. The optimal conditions for dye extraction were to extract the dried fruit hulls of mangosteen at 80°C for 1 hour with a 15 % w/v citric acid solution in a 1:4 ratio of mangosteen powder to solvent. Cotton dyeing with the extracted dye from the dried fruit hulls of mangosteen was carried out at 60°C for 60 minutes with a material to liquor ratio of 1:25. The effect on dyeing of mordant type with different mordanting methods was studied. The results showed that the dyeing of cotton using the post-mordanting method with ferrous sulfate and calcium hydroxide not only provided better depth of shade but also provided better wash fastness and light fastness than with other mordants (alum; zinc tetrafluoroborate) or without a mordant. Good fastness properties were also obtained using a post-mordanted silk with calcium hydroxide.     

Basic study on the two-tone color dyeing of PET and PVC wig fibers by carrier dyeing method

PET or PVC wig fibers are usually colored by the dope dyeing method in which the pigment or color master batch is mixed before the spinning process. However, the colored fibers need to be dyed again to obtain a two-tone color along the longitudinal fiber direction. In this study, PET and PVC fibers were dyed by the carrier dyeing method using a disperse dye, and the dyeing behavior was investigated. The fiber was dyed at various carrier and dye concentrations. The dye uptake increased with increasing carrier concentration or dye concentration. The saturation of the dye uptake was observed in each case. No change of the glass transition temperature (T_g) was observed in the 1st run of the DSC thermogram, however, a decrease in the value of T_g was observed in the 2nd run performed after the 1st run sample was quenched and re-measured. The reduction in the value of T_g implies that the carrier acted as a plasticizer in the fiber and enhanced the segmental mobility of the polymer chains. The dyeing temperature and carrier concentration were varied and the diffusion coefficients of the dye and activation energy were measured. The activation energy was increased at a higher carrier concentration, because the carrier acted as a plasticizer and lowered the energy barrier to the penetration of the dye molecule into the polymer chains.     

Ultrasonic dyeing of cationized cotton fabric with natural dye. Part 2: Cationization of cotton using Quat 188

The dyeing of cationized cotton fabric with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride 69% (Quat 188) using Cochineal dye was studied using both conventional and ultrasonic techniques. Factors affecting dye extraction and dye bath exhaustion were investigated. The results indicated that the dye extraction by ultrasound at 300 W was more effective at lower temperatures and times than conventional extraction. Also, the colour strength values obtained were found to be higher with ultrasound than with conventional techniques. However, the results showed that the fastness properties of the dyed fabrics with ultrasound are similar to those of the conventional dyed fabrics. The scanning electron microscope (SEM) and X-ray diffraction (XRD) were measured for cationized cotton fabrics dyed with both conventional and ultrasound techniques, thus showing the sonicator efficiency.     

Application of silver nanoparticles as an antibacterial mordant in wool natural dyeing: Synthesis,antibacterial activity,and color characteristics

Madder is a natural colorant which is commonly applied with metal salts as a mordant to improve its affinity to fibers and color fastness. Madder produces an insoluble complex or lake in the presence of metal ions on mordanted fabric. In this study, wool fabric was pretreated with AgNPs (silver nanoparticles) as a mordant, then dyed with madder. The wool fabric samples were examined by scanning electron microscopy (SEM) and their colorimetric characteristics were evaluated. The formation of spherical silver nanoparticle was confirmed using UV-Visible spectroscopy, SEM images, and elemental analysis. The average size of synthesized silver nanoparticles on the surface of wool fibers is around 73 nm. The dyed wool samples were pretreated with different concentration of Ag⁺ ions or AgNPs, which showed higher color strength value compared to untreated dyed wool fabric. This pretreatment also presented good antibacterial activity.     

Preparation and characterization of nanoscaled poly(vinyl alcohol) fibers via electrospinning

Nanoscaled PVA fibers were prepared by electrospinning. This paper described the electrospinning process, the processing conditions, fiber morphology, and some potential applications of the PVA nano-fibers. PVA fibers with various diameters (50–250 nm) were obtained by changing solution concentration, voltage and tip to collector distance (TCD). The major factor was the concentration of PVA solution which affected the fiber diameter evidently. Increasing the concentration, the fiber diameter was increased, and the amount of beads was reduced even to 0%. The fibers were found be efficiently crosslinked by glyoxal during the curing process. Phosphoric acid was used as a catalyst activator to reduce strength losses during crosslinking. Scanning electron micrograph (SEM) and differential scanning calorimetric (DSC) techniques were employed to characterize the morphology and crosslinking of PVA fibers. It was found that the primary factor which affected the crosslinking density was the content of chemical crosslinking agent.     

Performance of cotton fabric treated with an amino-terminated hyperbranched polymer

An amino-terminated hyperbranched polymer (HBP-NH₂), synthesized from methyl acrylate and diethylene tri-amine by polycondensation, was applied to treat cotton samples by a pad-dry-cure method. Physical properties, salt-free dye-ability, antimicrobial activity, and antiultraviolet property of the treated cotton samples were tested. The crystallinity and mechanical properties, including breaking strength, breaking elongation, and Young’s modulus of the treated cotton fibers, increased slightly in comparison with those of the untreated cotton fibers. The thermal stability and the moisture regain were also improved slightly. Dyed with direct dyes and reactive dyes in the absence of the electrolytes, the treated cotton fabric showed similar or higher color strength compared with the untreated cotton fabric in conventional dyeing. The treated cotton fabric can also be dyed with acid dyes effectively. In addition, the treated cotton fabric showed good antimicrobial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The study of the antiultraviolet properties of the treated cotton fabric indicated that the HBP-NH₂ contributed to the reduction of UV transmission and the increase of UPF.     

Extraction of natural dye from <Emphasis Type="Italic">Coreopsis tinctoria</Emphasis> flower petals for leather dyeing − An eco-friendly approach

This study evaluated the extraction of two colors of dye (yellow and brown) from Coreopsis tinctoria flower petals using ultrasound and the dyeing of leather with the extracted dyes as a source of nontoxic and eco-friendly dye. The results showed an increase in the dye extraction values with increasing time at 100 W ultrasonic power at 80 °C for 1 h. Leather dyeing was optimized with the aid of ultrasound and magnetic stirring. The optimum leather dyeing conditions, with respect to the dye uptake, dye penetration and intensity of the color, were determined to be 12 % dye concentration, 100 W power, 1,000 rpm, and pH 7.0 for 60 min at 80 °C. It was shown that sonication improves dye exhaustion from a 90 % to 60 % rating for 1 h of dyeing time. The dyed leather was assessed by reflectance measurements and compared with visual assessment data. The fastness properties of dyed leather samples showed good fastness against washing, light, and dry and wet rubbing. The strength properties were not significantly altered and the bulk properties, such as softness, were found to be improved by the use of Coreopsis tinctoria yellow and brown dyes using an ultrasonic and magnetic stirring dyeing process.     

Actinomycin X2, an Antimicrobial Depsipeptide from Marine-Derived Streptomyces cyaneofuscatus Applied as a Good Natural Dye for Silk Fabric

Actinomycins as clinical medicine have been extensively studied, while few investigations were conducted to discover the feasibility of actinomycins as antimicrobial natural dye contributing to the medical value of the functional fabrics. This study was focused on the application of actinomycin X2 (Ac.X2), a peptide pigment cultured from marine-derived Streptomyces cyaneofuscatus, in the dyeing and finishing of silk fabric. The dyeing potential of Ac.X2 with silk vs. cotton fabrics was assessed. As a result, the silk fabric exhibited greater uptake and color fastness with Ac.X2. Through Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses, some changes of chemical property for the dyed fabric and Ac.X2 were studied. The silk fabric dyed with Ac.X2 exhibited good UV protection ability. The antibacterial properties of dyed and finished silk were also evaluated, which exhibited over 90% antibacterial activity even after 20 washing cycles. In addition, the brine shrimp assay was conducted to evaluate the general toxicity of the tested fabric, and the results indicated that the dyed silk fabrics had a good biological safety property.     

Extraction,Dyeing, and Antibacterial Properties of <Emphasis Type="Italic">Crataegus Elbursensis</Emphasis> Fruit Natural Dye on Wool Yarn

Fruits obtained from shrubs of the Crataegus elbursensis (C. elbursensis) plant demonstrate significant antioxidant and antibacterial properties. In this study, natural dye was sono-extracted from fresh and dried fruits and applied in dyeing and antibacterial finishing of wool. The maximum sono-extraction yield was obtained when optimal conditions of ethanol/ water (4/1 v/v) as extracting solvent, time 30 min, pH 4, temperature 50 oC, and C. elbursensis concentration 10 g/l were used. When wool yarns were dyed with the extracted natural dye, the maximum dye uptake was achieved using dye concentration 75 % owf, and dyeing condition of 100 oC, 60 min, pH 4, and LR 100:1. Different metal salts like aluminum sulfate, copper sulfate, and tin chloride were applied on wool by pre-mordanting method and their effects on dye uptake, color variation, and color fastness were examined. Results showed that the natural dye itself had relatively high uptake and good color fastness on un-mordanted wool. Further, each mordant had different effect on dye uptake, color variation, and color fastness properties depending on its coordination ability with dye molecules and wool chains. Moreover, dyed yarns showed good antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria.     

Enhancing the dyeability of poly(lactic acid) fiber with natural dyes of alizarin,lawsone, and indigo

To dye poly(lactic acid) (PLA) fiber with natural dyes has gained importance in recent years due to the production of the fully eco-friendly textile products. In this study, pure and modified PLA fibers with two different POSS nanoparticles, namely N-phenyl aminopropyl POSS (AP-POSS) and octa (aminophenyl) polyhedral oligomeric silsesquioxane (OAPPOSS), are dyed with three different natural dyes including alizarin, lawsone and indigo. The effects of the dyeing conditions including dyeing temperature and time, POSS nanoparticle concentration, natural dye types and concentrations are investigated on the dyeability properties of the PLA fiber samples. The wash and light fastness of the fiber samples are also investigated. According to the dyeability results, it is concluded that POSS nanoparticles are effective for increasing the dyeability of the PLA fiber with all natural dyes used in this study. As the added amount of the POSS nanoparticle increases, the dyeability of the PLA fiber increases. When the performances of the POSS nanoparticles are compared, it is seen that OAP-POSS is more effective than the AP-POSS nanoparticle.     

Acid dyeing properties of meta-aramid fiber pretreated with PEO45-MeDMA derived from [2-(methacryloyloxy)ethyl] trimethylammonium chloride

A diblock copolymer (PEO₄₅-MeDMA) derived from [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MeDMA) was synthesized and applied to the dyeing of the meta-aramid fibers with some acid dyes. This copolymer created positive charges on meta-aramid fiber surface and a strong attraction with anionic groups of acid dyes. Meta-aramid fabric was pretreated using the synthesized copolymer and then dyed with two commercial acid dyes. The dyeability was found to be directly dependent on the concentration of PEO₄₅-MeDMA, pH in the dyebath as well as dye concentration. The color fastness of the copolymer pretreated dyed fabric was also evaluated.