Higher Color Strength Research Articles

Cerium sulfide pigments

Abstract Cerium sulfide pigments belong to the inorganic orange and red pigments. They were developed to substitute cadmium and lead containing red and orange colored pigments, in particular in plastics. Cerium(III) sulfide exists in three allotropic modifications, but only γ-Ce2S3, which is colored dark red, is suitable for the use as a pigment. Cerium sulfide pigments are characterized by high color strength, strong hiding power and sufficient thermal stability. Their limited stability in water containing systems and in humid atmospheres is not without problems. The pigments tend to degradation in the presence of water or humidity to form hydrogen sulfide, which limits the application possibilities significantly.

Bleaching of Jute-Cotton blend fabric with Peracetic acid for deep dyeing

The purpose of this study was to introduce sustainable bleaching of jute-cotton blend (Juton) fabric with Peracetic acid instead of conventional peroxide bleaching agents for the deep dyeing process. Juton was bleached with peracetic acid by varying the process conditions including temperature, pH, treatment time,concentration and the dyeing properties, fastness properties were investigated in a comparative manner. In addition, the physical properties of treated fabrics such as tensile strength, elongation, weight loss and the chemical changes of bleached fabrics were evaluated by using FT-IR. The morphological surface changes of bleached fabric were confirmed by SEM. Peracetic acid and hydrogen peroxide bleaching effluents were analyzed by measuring BOD, COD, TDS and DO values. The highest color strength was obtained at 70̊C,using neutral pH (7), concentration 20 mg/L in 80 min treatment time based on peracetic acid bleaching agent for Juton fabric. Peracetic acid bleaching of Juton fabric was found to be higher tensile strength and elongation than H2O2 bleaching. Peracetic acid bleaching effluent exhibited lower BOD, COD, TDS and higher DO than hydrogen peroxide bleaching effluent. Moreover, peracetic acid bleaching provided higher fastness to washing,light and rubbing than hydrogen peroxide bleaching.

Effect of Diethylene Glycol on the Inkjet Printability of Reactive Dye Solution for Cotton Fabrics.

Digital inkjet printing technology plays an increasingly important role in textile printing. The printing printability of reactive dye inks is the key to improving the quality of printed fabrics. In this study, an eco-friendly and simple method to improve the inkjet printability of reactive dye solutions was proposed. The influence of diethylene glycol on the surface tension, rheology, and dye molecule aggregation properties for three reactive dye solutions was investigated. The jetting performance of dye solutions was explored by observing droplet formation. Moreover, the color performance of printed cotton fabrics, including reactive dye solution penetration, colorimetric values, and color strength, was evaluated. Addition of diethylene glycol could change the aggregation of dye molecules by hydrophobic forces and hydrogen bonds. Diethylene glycol could inhibit formation of satellite droplets by changing the viscosity and surface tension of solutions, which made the pattern printed on cotton fabrics show regular edge sharpness. Furthermore, the dye solutions containing 10% DEG not only satisfied various properties of reactive dye inks but also had the highest color strength and the deepest and brightest colors.

Pilot scale water free dyeing of pure cotton under supercritical carbon dioxide

Supercritical carbon dioxide (scCO2) is a green, safe and environmentally friendly medium in textile dyeing. It is, indeed representing a salient advancement in modern dyeing of textiles. However, to the authors' knowledge, current methods of dyeing 100% unmodified cotton fabrics under supercritical medium up to pilot scale encounter many problems, challenges and a variety of severe shortages. Thus, the aim of the current work is to develop a method for dyeing unmodified 100% cotton fabrics using vinyl sulphone reactive disperse dye under scCO2. Two types of cotton (woven & knitted) fabrics were dyed with N,N‑diethyl-4-((4-vinylsulfonyl)phenyl)diazenylaniline disperse reactive dye, in the presence of disodium edetate as a swelling agent under scCO2. The results indicate that vinyl sulphone dye has high color strength (K/S) values on cotton fabrics using the organic electrolyte (disodium edetate). The system parameters, mainly temperature, pressure, time were investigated. The proposed methodology has been confirmed by carrying out a pilot-scale experiment using the optimum conditions obtained from lab-scale. The results proved that dyeing cotton under scCO2 medium on pilot level is possible. However, more efforts are needed to develop more dyestuffs with different colors that suitable for cotton dyeing.

The investigation of broad-absorbing tetrabenzocorrolazine dye-based black matrix of low dielectric constant

Tetrabenzocorrolazine dyes with high color strength and broad absorbance derived from a phthalocyanine moiety were designed and synthesized for a color filter on an array-mode black matrix of low dielectric constant. The prepared tetrabenzocorrolazine dyes focused the absorbance of phthalocyanine further into the visible light range so that the color was considerably closer to black, while making it easier to introduce an axial substituent in the vertical direction to the dye main body, thereby markedly improving its solubility in industrial solvents. Upon mixing with a perylene dye of 450-550 nm absorbance and a thermosetting resin composition, dye-based black matrix films with high optical density values, associated with superior light shielding capability, were fabricated. The prepared black matrix films not only ensured thermal resistance by allowing easy intermolecular cohesion but also served as an insulating membrane that did not interfere with the thin film transistor electric signals, exhibiting a value of 3-5 when dielectricity was measured as the most critical factor for the color filter on array mode display panels.

Application of persimmon (Diospyros kaki L.) peel extract in indigo dyeing as an eco-friendly alternative reductant

The aim of this study is to investigate the efficacy of persimmon (Diospyros kaki L.) peel extract as a reductant for indigo dyeing. Dried persimmon peel was water extracted and its sugar contents and functionalities were determined. Its reducing power was studied in terms of redox potential of the indigo bath and color strength (K/S value) of the ramie fabrics dyed in the indigo reduction bath. Total sugar content of the extract was 74.3%. Antioxidant capacity reached up to 86.0% at 3.5 μg/mL of the extract concentration. The persimmon peel extract had an effect on indigo reduction and the maximum color strength was obtained within one or two day. At 2–3% of the extract concentration, the redox potential of the indigo bath was maintained in the range of − 550 ~ − 600 mV for 10 days. With increase in the extract concentration, reduction state lasted for longer time and higher color strength was obtained. The persimmon peel extract can be used for indigo reduction dyeing as a sustainable, nontoxic, biodegradable alternative to sodium dithionite.

Superheated water hydrolyses of waste silkworm pupae protein hydrolysate: A novel application for natural dyeing of silk fabric

A large amount of by products are generated during the silk processing, the most abundant of which are silkworm pupae. In general, efforts have been made to use these by-products for different applications such as biogas, fertilizer, human food products, medicines and pupa oil production. In this work a novel application of protein extracted from silkworm pupae was proposed for the coloration of silk fabrics within the context of the circular economy. In particular, for the first time a hydrolysis process at 170 °C for 1 h using only superheated water was performed to extract proteins from silkworm pupae and as a novelty, the same proteins were used to dye silk fabrics. Various parameters such as temperature, time, pH, dyeing time and temperature, protein hydrolysate concentration, mordant type (copper sulfate and ferrous sulfate) and mordanting step (pre-meta-post) were studied and the higher color strength was obtained at pH 3.8, 90 °C, for 60 min dyeing time using 30% o.w.f. protein hydrolysate, 50% o.w.f meta-mordanting. It was demonstrated that the extracted proteins can actually dye, but the color is more intense in the presence of the mordant which plays an anchoring role by formation of complex between protein hydrolysate and silk fabric. Dyed fabrics in the presence of mordant show washing and rubbing fastness from good to excellent, and light fastness from fair to good.

Improving Dyeing Parameters of Polyester/Cotton Blended Fabrics by Caustic Soda, Chitosan, and Their Hybrid

The production of polyester fibers has been dynami‌cally increased, accompanied by the common use of polyester-cotton blends. In this research work, polyester (100%), cotton (100%), and polyester-cotton blend fabrics (50/50) have been subjected to treat with caustic soda, chitosan and their hybrid, followed by one-bath two-stage dyeing with reactive dye (Reactive Red 198 RR198), to study their dyeing performance and morphology. SEM images of polyester treated and untreated with caustic soda, it describes the ease of adsorption on the alkaline modified fabric surface. The one bath two step method was used to shorten the dyeing process, increase yield and reduce the utility and chemical cost. In the final stage, the dyed fabrics were tested for color strength (K/S) value, dye intensity, fixation% in addition to, fastness properties evaluated by testing the light, washing and perspiration fastness properties of the dye. The results clearly show that for all pre- treated fabrics using caustic soda (90 g/dm3 of caustic soda, 100 min ; 80oC), favorable absorption of reactive dye RR198, resulting a high color strength and fixation % due to surface modification of polyester and mercerization of cotton fabrics. The effect of chitosan pretreatment on dyeability, fastness, and some physicochemical properties has been investigated. Hybrid treatments of textile materials by combining alkali and chitosan are potentially the most effective for improved dye color strength and fixation % and it could be applied as a novel approach to textile dyeing and finishing.

Green Dyeing of Silk Fabric with Turmeric Powder Using Tamarind Seed Coat as Mordant

The current study is aimed to explore the sustainable dyeing approach of silk fabric with turmeric powder using tannin as mordant extracted from tamarind seed coat. For that, tamarind seed coat tannin was extracted and applied as natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing silk fabric with the extract of turmeric powder. Dyeing parameters such as temperature, time and mordant concentration were varying for optimizing the process. The color strength, color coordinates, color fastness to wash, perspiration, water and rubbing were evaluated for examining dyeing performance. Firstly, tannin was extracted from tamarind seed coat and applying on the silk fabric at 95°C temperature for 45 min by varying concentration. Among them 15 g/l shows better results. Some samples were mordanted with both 15 g/l extracted tannin and 0.5% copper sulphate solution. The mordanted samples were dyed with turmeric dye by varying the time and temperature. By analyzing the test results, the sample mordanted with extracted tannin showed high color strength and good fastness properties dyeing at 80°C for 60 min. The application of 0.5% copper sulphate mordant enhanced sustainable wash fastness properties.

Sustainable application of cochineal-based anthraquinone dye for the coloration of bio-mordanted silk fabric.

Natural colors particularly animal-based colorants are employed in the field of cosmetics, food, and flavors and also gaining popularity in textiles, due to their soothing nature. In this study, the microwave-assisted extraction of colorant from cochineal insects for dyeing of bio-mordanted silk has been carried out. Acidic, methanolic, and acidified methanol solubilized media were used to extract the natural colorant from cochineal under microwave irradiation for 1-6min. Bio-mordants have been employed at optimized conditions to make the process greener and sustainable. It is found that acid solubilized extract of pH4, employed at 55°C for 55min containing 5g/100mL of Glauber's salt as exhausting agent has given high color strength onto microwave-treated silk fabric. Suggested ISO standards for colorfastness have revealed that bio-mordants have given excellent color depth and excellent rating of fastness properties, compared with chemical mordants used. It is found that microwave treatment has not only improved the dyeing behavior of colorant extracted from cochineal in acid solubilized medium but also enhanced the color characteristics onto bio-mordanted silk fabric.

English

Functional finishes are agents that are applied to fabrics to make them suitable for specific uses and contribute a specific attribute to a fabric without altering its appearance.  In this context, the present study reveals the importance of dyed fabrics with Datura stramonium plant leaf extracts to control antibiotic-resistant bacteria, which have been a threat to human health and posed noticeable challenges confronted with medical physicians in the treatment of many infectious diseases. More still, the importance of using natural dye is not limited to its antimicrobial and other medicine values but also to its wide range of advantages via elimination of environmental pollution due to the usage of synthetic dyes. 100% plain woven, desized, scoured and bleached cotton fabric samples and 100% degummed and bleached hand knitted silk fabric samples were dyed with aqueous extracts from D. stramonium plant leaves in combination with Alum and Iron Sulphate as mordants using post-mordanting method and then tested against two strains of Staphylococus aureus (Gram-positive bacteria) and Pseudomonas aeruginosa (Gram-negative bacteria) using Agar diffusion method as per SN195920-1992 standard. The fastness properties (wash fastness, light fastness and rubbing fastness) of the dyed fabrics were assessed following guidelines from The American Association of Textile Chemists and Colorists (AATCC) and International Organization for Standardisation (ISO) testing methods. Spectrophotometric experiments were employed to evaluate the colour strength (K/S) of the dyed samples. The antimicrobial activity results showed that for both cotton and silk dyed fabric samples; there was an interruption of the microbial growth beneath the fabric and a clear zone of inhibition around the fabric. Dye ability and fastness results showed that dyed fabric samples with D. stramonium extracts using mordants had relatively high colour strength (K/S) values as compared to the control fabrics which were dyed without a mordant and their colorant was more stable to light, rubbing and washing, respectively.   Key words: Antimicrobial activity, silk fabric, cotton fabric, Datura stramonium extract, mordants.

Colouration and bio-activation of polyester fabric with curcumin in supercritical CO2: Part II – Effect of dye concentration on the colour and functional properties

This study presents a sustainable approach to the fabrication of multifunctional polyester fabric with bioactive natural colourant curcumin through a water free supercritical CO2 dyeing technique. A simple dyeing process was carried out in which curcumin powder dye was directly applied to polyester fabric in scCO2 medium without involving mordant chemicals and fabric pre-treatment procedures. The colour, bioactivity, and durability properties of the dyed samples were characterized. Results showed that the colour strength increases when the dye concentration increases and higher colour strength (K/S value above 17) could be achieved using low curcumin concentration (ca. 0.75 % owf). Moreover, the dyed fabrics displayed desirable antimicrobial, antioxidant, and UV-protection activities with acceptable colour fastness to washing and rubbing. This study opens a new view towards the sustainable fabrication of coloured and bioactive polyester fabric using curcumin via a resource-efficient and eco-friendly scCO2 dyeing technique.

Inorganic nanoparticles and natural dyes for production of antimicrobial and antioxidant wool fiber.

Ag/Cu2O/ZnO nanoparticles (NPs) were synthesized in situ on wool yarns. The wool yarns were subsequently dyed with the roots and stems of berberis vulgaris. The antibacterial, antioxidant, and dyeing properties of the treated wool yarns were studied. Scanning electron microscopy (SEM), differential scanning calorimeters (DSC), and weight gain (%) analyses were employed for the characterization of the treated samples. The results indicated that the highest color strength (K/S) was obtained at a dye concentration of 50% over the weight of fiber (o.w.f.), temperature 100°C, time 60min, and pH 5. Moreover, the antioxidant and antimicrobial activities of the treated samples with NPs, and dyed with roots and stems of berberis vulgaris were excellent (about 100%). The treated samples with Ag NPs and dyed with the natural dyes showed very high antimicrobial activity (> 84%) after 10 repeated washing cycles. Finally, the colorfastness properties of the dyed and treated wool samples against washing and light irradiation were studied. It was concluded that the roots and stems of berberis vulgaris could be considered as suitable natural colorants for dyeing of wool yarns with acceptable colorfastness properties, excellent antimicrobial and antioxidant activities.

Optimization of the cationizing condition in salt‐free reactive dyeing of cotton fabric with the pad‐irradiate‐pad‐steam process using response surface methodology

AbstractResponse surface methodology is widely used in the optimization of dyeing conditions. Herein, the color strength and dye fixation rate of the cotton fabric dyed by pad‐irradiate‐pad‐steam (PIPS) process were determined and compared to by conventional pad‐dry‐pad‐steam (PDPS) process. Then the response surface methodology and central composite design were used to optimize the cationizing conditions during the pad‐irradiation step of the process to obtain high color strength during the subsequent salt‐free reactive dyeing of the cotton fabric via a pad‐steam process. The obtained experimental data were fitted to the second‐order polynomial equation, and response surface plots and contour plots were used to identify the optimal cationizing condition, the 3‐chloro−2‐hydroxypropyltrimethylammonium chloride concentration of 104 g/L, the microwave irradiation power of 537 W, the treatment time of 6 min, and the molar ratio of sodium hydroxide to 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride of 1.02. The results showed that the experimental color strength of the cotton fabrics was in close agreement with the value predicted by the model and the optimal cationizing condition was obtained precisely.

Analysis and Study of Effect of Natural Dye From Bombax malabarica on Silk Fabric

The current study deals with the extraction of natural dye from Bombax malabarica flowers, readily available by-product. Dye was extracted under different operating conditions such as time (60–90 min), temperature (90–95 °C), and pH 9. The dyed samples were subjected to CIELAB system using Gretag Macbeth Color Eye 7000A Spectrophotometer for the evaluation of color strength and L*a*b* C and H values. To improve the dye uptake and color fastness, pre and postmordanting was carried out using alum, tannic, and tartaric acid mordants. Dyed silk fabrics were tested for its color fastness when subjected to light, washing, and rubbing. Fastness properties of dyed silk fabric samples were found considerably good. Mordanted silk fabric samples showed increase in dye uptake resulting in high color strength and better fastness properties. The dyed silk samples displayed good antimicrobial activity (reduction rate: 48%) against the bacteria Escherichia coli and (reduction rate: 55%) against Staphylococcus aureus.

Novel Approach to Dye Polyethylene Terephthalate (PET) Fabric in Supercritical Carbon Dioxide with Natural Curcuminoid Dyes

The use of natural dyes has increased in the last few decades due to the eco-friendly approach of dyeing. There are still some limitations that are associated with natural dyes, such as dyeing efficiency, reproducibility of shades, process complexity, availability etc. The main problem associated with the dyeing property of natural dyes is “low exhaustion”. In this study, natural dyestuff from Curcuma longa L. was extracted and polyethylene terephthalate fabric was dyed with it in the same bath by employing the supercritical carbon dioxide method. The method was developed to improve the dye-ability of natural dyes and reduce the process time and effluent. Curcuminoid dye exhaustion on PET fabric showed almost 80% by using supercritical carbon dioxide dyeing methods, and the highest colour strength (K/S = 12) was obtained. Coloured polyethylene terephthalate fabric treated with supercritical carbon dioxide showed deeper shades (L* = 72.92) and better fastness properties as compared with high temperature exhaust dyeing methods.

Synthesis of novel biologically active thiazole dyes and their applications

PurposeThis study aims to focus on the possibility of developing new thiazole azo dyes with good colouristic application properties, biological and pharmacological activities.Design/methodology/approachCoupling of curcumin with different aromatic diazonium salts of 2-amino thiazole derivatives, such as 2-aminobenzothiazole, 2-amino-5-phenylthiazole, 2-amino-5-methylthiazole and 2-amino-5-nitrothiazole-produced novel azo dyes. Structures of all synthesised dyes were fully confirmed via spectroscopic and analytical methods. Those compounds were examined for their antimicrobial, anticancer and antioxidant activities. They were applied on polyester fabrics and, subsequently, their dyeing properties, light, washing, perspiration, rubbing and sublimation fastness were determined.FindingsPrepared dyestuffs were suitable for dyeing polyester fabrics. It was found that all prepared dyes possess high colour strength, as well as good overall fastness properties. Meanwhile, the synthesised compounds exhibited good biological and pharmacology activity.Research limitations/implicationsSynthesis of these four azo dyes for textile dyeing was not conveyed earlier.Practical implicationsThaizolyl disperse dyes were responsible for giving better colour assessment and fastness properties on polyester fabrics.Social implicationsAlthough, most of synthesis eco-friendly dyes are expensive, they are showing a good antimicrobial and anticancer activity.Originality/valueIt gave straightforward approach to synthesise novel thiazolyl azo dyes with good biological, pharmacology activities, good colour assessment, and fastness properties.

Comparison of Dyeing and Functionalization Potential of Some Selected Plant Extracts Applied on Cotton Fabric

ABSTRACT In wake of eco-friendly approach, there is a growing trend to impart various functional attributes in textile substrates through green chemistry approaches. In this context, a comparative study of coloration, mosquito repellency, UV protection and antimicrobial potential was made for seven plant extracts applied on cotton fabric. The plant biomass include leaves of Lawsonia inermis, rhizome of Curcuma longa, bark of Acacia nilotica & Eucalyptus globules, peels of Punica grantum & Allium cepa and flowers of Tagetes erecta. For this purpose, extracts of these plants biomass were applied on cotton fabric samples and evaluated for their color strength by Kubelka-Munk equation; anti-microbial potential by zone of inhibition in bacteriostasis agar; UPF for UV protection by ultraviolet absorbance analysis; mosquito repellency by percentage insect landing and percentage repellency. It was found that T. erecta showed good mosquito repellency, UV protection and antimicrobial potential along with its exceptionally high color strength value but poor fastness properties. However, A. nilotica demonstrated outstanding fastness properties but showed moderate color strength value.

Use of Aronia melanocarpa Fruit Dye Combined with Silver Nanoparticles to Dye Fabrics and Leather and Assessment of Its Antibacterial Potential Against Skin Bacteria

The core purpose of this study was to extract natural dye from Aronia melanocarpa (black chokeberry) powder (BCP) via soxhlet extraction or ultrasound water bath using acidified ethanol (A. EtOH) as the extraction solvent. After optimization of the dye extraction conditions, high color intensity was achieved at pH 4, temperature of 80 °C, 40 and 90 ml of A. EtOH, 2 g of BCP, time of 80 and 90 min, ultrasonic output power of 75 W or 6 extraction cycles for ultrasonic water bath and soxhlet extraction, respectively. The extracted red natural dye (BCP) was used alone or together with commercial silver nanoparticles (C-AgNPs) to dye cotton, silk, and leather in an eco-friendly approach without using any external chemicals with augmented antibacterial activity. Rotary vacuum dyeing yielded excellent dyeing and the optimal conditions for high color strength (K/S) values were pH 4, 120 min at 80 °C for cotton and silk and 90 min at 60 °C for leather. Morphologies of dyed cotton, silk, and leather and the anchoring of C-AgNPs with elemental compositions were investigated by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). The dry and wet rubbing fastness values for dye alone and dye with nanoparticles were grade 4–5 and 4, respectively.

Super stretchable chromatic polyurethane driven by anthraquinone chromogen as a chain extender.

A novel polyurethane elastomer (PUE) that exhibited high tensile strength, large elongation at break, great color strength and supreme color fastness was successfully designed and synthesized. The PUEs were prepared with isophorone diisocyanate (IPDI) as hard segments, polycarbonate diol (PCDL)/polytetrahydrofuran glycol (PTHF) as mixed soft segments, and anthraquinone chromogen as the chain extender agent. The relationships between the mechanical properties/color performance and chromogen addition content were investigated. The chromogen actual access rate of the obtained BPUEs was evaluated by UV-Vis. The clear tortuous surface and entanglements were exhibited in PUEs micromorphology structure, indicating a significant reinforcement of mechanical properties. Elongation-at-break and tensile strength reached the maximum value 2394% at 1% (BPUE1) and 18.29 MPa at 5% (BPUE5), respectively, and then decreased as chromogen addition content increased. Mechanical testing results correlate well with XRD and SEM findings, which proved that anthraquinone chromogen induced an improvement in phase separation. Furthermore, BPUE films displayed high color strength and excellent color fastnesses. The rubbing fastness and washing fastness of BPUE1 and BPUE0.5 reached grade 5, respectively. These inspiring findings suggest that PUE films with superb performance have potential to be directly applied in the textile field.