Eco-friendly dyeing using natural mordant extracted from <Emphasis Type="Italic">Emblica officinalis G</Emphasis>. Fruit on cotton and silk fabrics with antibacterial activity

Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.     

Dimensional and physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns

In this study, the dimensional and some physical properties of plain knitted fabrics made from 50/50 bamboo/cotton blended yarns are investigated. In order to see the differences and similarities, the results are then compared with those for similar fabrics knitted from 50/50 conventional viscose/cotton and 50/50 modal/cotton blended yarns. Each fabric type was produced with three different stitch lengths. After all fabrics were dyed under identical dyeing conditions, they were subjected to dry and full relaxation treatments. For dimensional properties of fabrics, course, wale and stitch densities were measured. Then, by calculating statistically best-fit lines passing both through the experimental points and the origin, dimensional constants i.e. k values were predicted in terms of the fiber types. The result show that each fabric type knitted from bamboo/cotton, viscose/cotton and modal/cotton blended yarns behaves in a similar manner. However, in both dry and fully relaxed states, the modal/cotton knitted fabrics tend to have slightly higher k values than the bamboo/cotton and viscose/cotton knitted fabrics. For physical properties, fabric weight per unit area, thickness, bursting strength, air permeability and pilling were evaluated. The results show that the weight, thickness and air permeability values are independent of the fiber type. Plain knitted fabrics from modal/cotton blended yarns have the highest bursting strength values. Plain knitted fabrics from bamboo/cotton blended yarns tend to pill less.     

Dyeing properties and colour fastness of cotton and silk fabrics dyed with<Emphasis Type="Italic">Cassia tora L.</Emphasis> extract

A natural colorant was extracted fromCassia tora L. using buffer solutions (pH: 2–11) as extractants. The dyeing solution (Cassia tora L. extract) extracted using pH 9 buffer solution was found to give the highest K/S values of dyed fabrics. Cotton and silk fabrics were dyed withCassia tora L. extract at 60°C for 60 min with pre-treatment of various metal salts as mordants. It was found thatCassia tora L. extract was polygenetic dyestuffs and its major components were anthraquinones. Studies have been made on the effects of the kind of mordant on dyeing properties and colour fastnesses of cotton and silk fabrics. The K/S of cotton fabrics increased in the order of the dyeing using FeSO₄>CuSO₄>ZnSO₄>MnSO₄≅Al₂(SO₄)₃>NiSO₄>none, however, the K/S of silk fabrics increased in the order of the dyeing using FeSO₄>CuSO₄>ZnSO₄≅Al₂(SO₄)₃>MnSO₄≅NiSO₄>none. It was found that the K/S values of dyed fabrics were largely affected by the colour difference (ΔE) between mordanted fabric and control fabric. However, they were not depended on the content of mordanted metal ion of the fabrics. Mordants FeSO₄ and CuSO₄ for cotton fabric, FeSO₄, CuSO₄, and Al₂(SO₄)₃ for silk fabric were found to give good light fastness (rating 4).     

Dyeing, fastness, and deodorizing properties of cotton, silk, and wool fabrics dyed with gardenia, coffee sludge, Cassia tora. L., and pomegranate extracts

Four kinds of natural dying solutions (natural colorant extracts) were obtained by extraction from gardenia, coffee sludge, Cassia tora. L., and pomegranate using water at 90°C for 90 min with a liquor ratio (solid natural colorant material/solvent water, weight ratio) of 1/10. The dyeing, colour fastness, and deodorizing properties of cotton, silk, and wool fabrics dyed with natural colorant extracts were compared. It was found that these properties were significantly dependent on the concentration of extracts, the structure of colorant, and the kind of fabrics. The order of colour strength (K/S) is Cassia tora. L., pomegranate, coffee sludge, and gardenia. Colour fastness (light, water, and perspiration fastness) was in the range of 2nd–5th grades. The deodorizing performance of fabrics dyed with various natural colorant extracts was in the range of 50–99 %. The deodorizing performance increased in the order of gardenia < Cassia tora. L. < coffee sludge < pomegranate. Especially, the deodorizing performance of all fabrics dyed with pomegranate was found to be highest at 99 %.     

Low stress mechanical properties of fabrics woven from bamboo viscose blended yarns

This paper presents the low stress mechanical properties of plain fabrics woven from cotton, bamboo viscose and cotton-bamboo viscose blended yarns. Three blends (100 % cotton, 50:50 cotton-bamboo and 100 % bamboo) were used to produce three yarn counts (20, 25 and 30 Ne). Each of these yarns was used to make fabrics with different pick densities (50, 60 and 70 picks per inch). It was found that bending rigidity, bending hysteresis, shear rigidity, shear hysteresis and compressibility is lower for bamboo fabrics as compared to those of 100 % cotton fabrics. On the other hand, extensibility, tensile energy and compressional resilience are higher for 100 % bamboo fabrics than 100 % cotton fabrics. Higher pick density increases linearity of load-elongation curve, bending rigidity, shear rigidity and compressional resilience. Shear and bending rigidities show very good correlation with the respective hysteresis values.     

Natural dyeing with black cowpea seed coat. I. Dyeing properties of cotton and silk fabrics

A new trial to determine the dyeing properties of cotton and silk fabrics with a black cowpea seed coat as crop waste was investigated. The natural dye anthocyanins were extracted from a black cowpea seed coat in an aqueous solution and used to dye silk and cotton. The optimal conditions for colorant extraction were an aqueous solution of a dried seed coat of black cowpea in a 1:10 liquor ratio at 70 °C for 4 hours with pH of 4. The best dye-uptake of silk and cotton fabric were obtained when the pH was 3.5 and 3.0 respectively, the temperature was 80 °C for 1 hour and the liquor ratio of black cowpea was 1:20. Different colors as dusky brown, brown, faint yellow, light green, reddish brown, cyan and green could be obtained using a various kind of mordants. The depth and brightness of color tones were affected by different dyeing and mordanting pH conditions. The colors of the fabrics were examined using a computer color matching system in terms of the K/S values and CIELAB color-difference values. The dyeing was evaluated using standard light, wash and heat fastness tests. Good wash and heat fastness were obtained but the poor light fastness indicated the need for improvement to fulfill the requirement for textile applications.     

Cutinase treatment of cotton fabrics

Our study proposes an enzymatic scouring method for cotton fabrics using the enzyme cutinase. We established cutinase treatment conditions for cotton fabrics from their relative activity at different pH levels, temperatures, enzyme concentrations, and treatment times. Weight loss, moisture regain, K/S value, tensile strength, and SEM micrographs of cotton fabrics were analyzed. We determined the optimum cutinase treatment conditions to be as follows: pH of 9.0, temperature of 50°C, cutinase concentration of 100 %, and a treatment duration time of 60 min. We discovered that this cutinase treatment hydrolyzed the cuticle of cotton fabrics. The cutinase treatment did not decrease the moisture regain and the K/S value. The optimum concentrations of Triton X-100 and calcium chloride, which were used as auxiliaries for cutinase treatment, were found to be 0.5 % (v/v) and 70 mM, respectively. Some cracks were observed on the surface of the cotton fibers; however, the tensile strength did not decrease.     

Reversible and washing resistant textile-based optical pH sensors by dyeing fabrics with curcuma

Curcuma powder was used to dye cotton and polyamide 6,6 fabrics in order to produce textile-based optical pH sensors. Both fabrics showed a bright yellow color after dyeing and demonstrated color changes (towards red) when contacted with basic solutions. Color change and sensitivity differ for cotton and for polyamide. Curcuma-dyed cotton shows color changes in particular in the range of pH between 6.5 and 8.5, whilst curcuma-dyed polyamide shows a wider pH range: from 8.5 to 13.0. The stability of pH sensing to washing was evaluated. Three different kinds of washing agents were used in order to simulate the real life conditions of a garment or a cloth. Standard test methods were used when available for washing tests. The pH sensing of the curcuma-dyed fabrics demonstrated an excellent fastness to all kinds of washing. Ionic strength of the solution does not affect the color changes. Moreover, color reversibility of the fabrics was proven, too. Color change and reversibility of the fabrics was assessed by an UV-visible spectrophotometer. Spectral changes were observed at 540 nm for curcuma-dyed cotton, and at 487 and 574 nm for polyamide.     

Synthesis of HBP-HTC and its application to cotton fabric as an antimicrobial auxiliary

A quaternary ammonium compound, 2-hydroxypropyltrimethylammonium chloride amino-terminated hyper-branched polymer (HBP-HTC), was synthesized from an amino-terminated hyperbranched polymer (HBP-NH₂) and 2,3-epoxypropyltrimethylammonium chloride (EPTAC) as a grafting agent in aqueous solution. Its molecular weight and possible structure were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (¹H-NMR). The cotton fabric was treated with 2 g/l HBP-HTC aqueous solution for 30 min at room temperature to provide the cotton fabric with antimicrobial properties. The antimicrobial activities of the HBP-HTC aqueous solutions and the HBP-HTC treated cotton fabrics were evaluated quantitatively. The results indicated that the HBP-HTC treated cotton fabric showed 99.92 % reduction of bacteria S. aureus and 99.66 % reduction of bacteria E. coli, respectively. The antimicrobial activities of the HBP-HTC treated cotton fabrics were maintained at over 99.00 % reduction level even after being exposed to 20 consecutive home laundering conditions.     

Deodorizing and antibacterial performance of cotton, silk and wool fabrics dyed with Punica granatum L. extracts

Natural dye extracts were obtained by extraction from Punica granatum L. using water as an extractant at 90 °C for 90 min with various liquor ratios (solid Punica granatum L.(wt.): solvent water(wt.); 1:100–1:5). Dyeing was carried out using a 1:50 dyeing bath ratio at 80 °C for 60 min by exhaustion method. This study focused on the effect of liquor ratio on dyeing properties and deodorizing/antibacterial performance of various fabrics (cotton, silk and wool) dyed with Punica granatum L. extract without mordants. The optimum liquor ratio was found to be 1:10. By IR, UV-visible spectroscopies and HPLC analysis, the main component in Punica granatum L. extract and the yellow colorant component were found to be ellagic acid. By GC/MS analysis, the major volatile components of pristine Punica granatum L. powder were found to be acetic acid (area: 25.84 %), ethanol (area: 17.97 %), acetoin (area: 13.11 %), acetaldehyde (area: 8.96 %), isobutanal (area: 4.90 %). All dyed fabrics (cotton, silk and wool fabrics) displayed outstanding deodorizing performance (99 %) against ammonia gas and excellent antibacterial performance (bacteriostatic reduction rate: 99.9 %) against Staphylococcu aureus and Klebsiella pneumoniae.     

Eco-dyeing and antimicrobial properties of chlorophyllin copper complex extracted from Sasa veitchii

Cotton fabrics were dyed with the natural chlorophyll derivates (chlorophyllin, Chlin) after treatment with and without chitosan. The water-soluble Chlin extracted from Sasa veitchii based on Japanese bamboo leaves were investigated in order to improve the textile coloration and antimicrobial activity. The antimicrobial activity of the dyed fabrics that had been pretreated with chitosan as a biomordant over a concentration range of 0∼0.7 % was tested against two common gram pathogens: Staphylococcus aureus and Klebsiella pneumoniae. The color depth as measured by the K/S value, the color difference and the colorfastness to washing and light were also evaluated. The fabrics treated with chitosan resulted in an increase in dye uptake in all cases compared with the corresponding untreated fabrics, and did not affect fastness of washing and light. The cotton fabrics dyed with mordant and CuSO₄ extracts appeared to have over 99.9 % of antimicrobial activity, while MeOH extracts showed 71.8 %.     

An adsorption study of alum-morin dyeing onto silk yarn

Silk yarn was dyed with morin (2′,3,4′,5,7-pentahydroxyflavone) by using alum as mordant. In order to optimize the process, three methods of dyeing involving: pre-mordanting, simultaneous mordanting, and post-mordanting were assessed and compared with a mordant-free process. The adsorption of alum-morin dye onto silk fibers indicated that the adsorption capacities were significantly affected by pH, the initial dye concentration, and temperature. The initial dye adsorption rates of alum-morin dye on silk before equilibrium was reached increased with higher dyeing temperatures. The pseudo second-order kinetic model was indicated for alum-morin dyeing (simultaneous mordanting) of silk at pH 4.0 with an activation energy (E _a ) of 45.26 kJ/mol. The value of the enthalpy of activation (ΔH ^#) for alum-morin dyeing on silk at pH 4.0 was −31.29 kJ/mol. Also, the free energy (ΔG ^o) and entropy changes (ΔS ^o) for alum-morin dyeing on silk were −17.73 kJ/mol and −45.7 J/molK, respectively, consistent with a spontaneous and exothermic adsorption process.     

<Emphasis Type="Italic">In situ</Emphasis> deposition of silver nanoparticles on the cotton fabrics

A novel method was developed to prepare the antibacterial cotton fabrics through in situ deposition of silver nanoparticles on the cotton fabrics by the reduction of Ag⁺ without any reductant and dispersant. The data showed that by immersing the cotton fabrics in 160 mM AgNO₃ solution at 90 °C, the amount of silver nanoparticles was increased from 0.6890 to 1.3561 mg per gram of fabrics with the increase of reaction time from 10 to 50 min. The obtained cotton fabrics showed excellent antibacterial activity and laundering durability, in which the bacterial reduction was still 98.5 and 94.3 % to Escherichia coli and Staphylococcus aureus, respectively, even after the fabrics were washed for 20 cycles. Thus, this facile in stitu reduction method without any other reducers or stabilizers may bring a promising and green strategy to produce functional cotton fabrics.     

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.     

Curcuma Dye with Modified Treatment Using Chitosan for Superior Fastness

Curcuma dye could never gain popularity in natural dyeing as the intrinsic nature of the colorant Curcumin did not have the requisite adhering property towards natural fabrics such as silk and cotton, thereby making it very fugitive. In this paper attempts have been made to activate Curcumin molecule by complexation with chitosan (another natural linear polysaccharide). The binding took place at intrinsic pH (7–8) very effectively without any surfactant or enzyme. Dyeing with this new composite showed excellent wash and light fastnesses as compared to curcuma dye. The novelty of this dyeing process is the remarkable enhancement of wash and light fastnesses levels by 1.0–1.5 for silk and cotton fabric dyeing in just 1 hour at 40–45 °C. It is fast and energy conserving dyeing process. Three subsequent washing of the dyed samples showed very small change in CIE Lab.     

Water and oil-repellent coatings of perfluoro-polyacrylate resins on cotton fibers: UV curing in comparison with thermal polymerization

UV curing of perfluoro-alkyl-polyacrylate resins able to impart water as well as oil-repellency to cotton fabrics was studied in comparison with conventional thermal polymerization. The process was assessed through weight gain and gel content measurements while the properties conferred to cotton fabrics were determined in terms of water and oil contact angles, moisture adsorption, and water vapor permeability. The polymerization yields were of the same order (>80 %) of those obtained with thermal curing as well as the high contact angles with water (>127°) and oil (>118°) even at low resin add-on (3 %). UV cured resins yielded oil contact angles mostly higher than 120° denoting super oil-repellent surfaces. Moreover the water and oil-repellency was adequately maintained after washing. The moisture adsorption of finished fabrics was lower than that of untreated cotton, but slightly higher for UV cured than thermally treated fabrics. Water vapor transmission rate showed that the finish treatment, thermal as well as by UV curing, does not reduce the breathability of the original cotton. DSC analysis demonstrated that the fiber pyrolysis is affected by the polymer add-on, while FTIR-ATR spectra of all finished fabrics showed typical peaks of ester and C-F groups. XPS analysis showed small differences between thermal and UV curing coatings with each resin, while coatings with the lowest percentage of fluorine groups did not affect the water and oil-repellency.     

Flexural stiffness of core spun cotton/spandex weft knitted structures under relaxation and machine washing treatments

In this research work, behavior of flexural stiffness of core spun cotton spandex single jersey, 1x1 rib and interlock fabrics was studied under relaxation and machine washing treatments. Results are compared with similar fabrics made from 100 % cotton. Fabric weight density increased with the progression of treatments and it is proportionate to the fabric tightness factor (stitch length^?1). Even though both types of fabrics had same machine set stitch lengths, cotton/spandex fabrics have shown the higher fabric weight densities than that of 100 % cotton fabrics. Although 1x1 rib and single jersey fabrics knitted with the same machine set stitch lengths, rib fabrics have given higher fabric weight densities than single jersey fabrics. Among the three knitted structures, interlock fabrics with higher machine set stitch lengths gave the higher fabric weights. Fabric stiffness and flexural rigidity have given higher values under the progression of treatments and it was found that higher values of stiffness have given by cotton/spandex knitted fabrics compared to their cotton fabrics. Fabric stiffness and flexural rigidity in wale direction were higher than that in course direction, but it is only observed in single jersey fabrics. However, 1x1 rib and interlock fabrics have shown an opposite behavior. It was also observed a positive correlation between TF (i.e.: stitch length^?1) and bending length/flexural rigidity in both fabric types. Lower flexural rigidities reported with single jersey structures and highest values gave with interlock structures of cotton/spandex and cotton fabrics.     

A study on combining natural dyes and environmentally-friendly mordant to improve color strength and ultraviolet protection of textiles

In this study, natural dyes were extracted from five plants, namely diospyros kaki, dioscorea cirrhosa, millettia (jixueteng), ecliptae, and macrocarpa nucuma, using environmentally-friendly solvents, including ethanol and deionized (DI) water. A plant mordant, tannin extracted from Emblica officinalis G., and a metal mordant, copper sulfate, were used in the pre-dyeing process. Cotton and silk fabric samples were treated using the five natural dyes without and with mordanting for comparison on their color strength and characteristics as well as protection against ultraviolet radiation (UVR). Results revealed that Emblica officinalis G. had the highest total phenol content, followed by dioscorea cirrhosa. The presence of abundant phenolic groups in the natural dyes and mordant makes them effective coloration agents for fabrics. Cotton and silk fabrics dyed using ecliptae without pre-mordanting had the highest K/S values. Silk fabrics had higher K/S values than cotton fabrics, indicating greater color strength in pre-mordanted silk treated with DI water-extracted dyes. Natural mordant used before treatment with natural dyes contribute to significant enhancement in color strength, and Emblica officinalis G. alone could darken the color of cotton and silk fabrics dyed with plant pigment. Moreover, treatment with natural dyes after mordanting can increase ultraviolet protection factor (UPF) and the enhancement in UVR protection is greater and more significant in cotton fabrics than in silk fabrics, and in fabrics treated with DI water-extracted natural dyes than in those treated with ethanol-extracted ones. In conclusion, pre-dyeing with natural mordant followed by treatment with natural dyes extracted using environmentally-friendly solvents can enhance significantly K/S and UPF, offering directions for manufacturing textiles without environmental hazards but with good appearance and health benefits.     

Flame resistant modification of silk fabric with vinyl phosphate

The flame resistant finishing of silk fabric is still a challenge because most of the available treatment methods usually result in insufficient laundering durability. In this paper, a vinyl phosphorus-based monomer diethyl-2-(methacryloyloxyethyl) phosphate (DEMEP) was applied onto silk fabrics by graft copolymerization technique using potassium persulfate as an initiator. FT-IR spectra and amino analysis showed the evidence of the reaction between DEMEP and silk. The silk fabrics treated with DEMEP have excellent self-extinguishing property when the DEMEP add-on is over 50 % wt of silk fabrics. The LOI of treated samples is at least 28 % when the weight gain is 10 %. After being subjected to 30 hand wash cycles, DEMEP treated silk fabric can still pass the vertical flammability test. Thermal gravimetric (TGA) and differential thermal analysis (DTA) were applied to explore the thermal decomposition of silk fabrics treated with DEMEP. The initial decomposition temperature of silk fabric treated with DEMEP was shifted to a lower temperature. And at the end of decomposition at 700 °C, the char residue of silk fabric treated with DEMEP was higher than that of the control sample.     

Psychoacoustic characteristics of fibers

In order to investigate psychoacoustic characteristics of fibers, and to compare them with sound physical parameters, each sound of 25 different fabrics consisted of a single fiber such as wool, cotton, silk, polyester, and nylon was recorded. Sounds of specimens were transformed into critical band diagram and psychoacoustic characteristics including loudness and sharpness for each sound were calculated based on Zwicker’s models. Physical parameters such as the level pressure of total sound (LPT), level ranges (ΔL), frequency differences (Δf), AR coefficients (ARC, ARF, ARE) were obtained in fast fourier transform (FFT) spectrum. Nylon taffeta showed higher values for loudness than 2.5 sone corresponding to human low conversation, while most silk fibers generated less louder showing lower values for loudness than 1.0 sone. Wool fibers had higher loudness mean value than that of cotton, while the two fibers didn’t differ in LPT. Loudness showed high positive correlation coefficients with both LPT and ARC. Sharpness values were higher for wool fiber group than other fibers. Sharpness was not concerned with loudness, LPT, and ARC, but the fabrics with higher values for sharpness tended to show higherΔL.