Dye Color Research Articles

COMBINED ACTION OF ADSORPTION AND CATALYTIC OXIDATION IN ALUMINUM DYE REMOVAL BY GROUNDWATER TREATMENT WASTE

The performance of groundwater treatment waste (GWTW) as an adsorbent and catalyst in the decoloration of aluminum dye Sanodure green LWN (SG) solution was investigated. The raw GWTW was more suitable for dye removal than calcined at 800 °C temperature. The catalytic activity of GWTW in Fenton-like reactions in sunlight increases with decreasing pH from 5.5 to 2.5 and increasing temperature from 20 to 60 °C. The rate of 70% decoloration in the first 5 min and 92% after 50 min of 100 mg/L SG dye solution was reached at 50 °C and pH 3. Kinetics of the SG dye color removal fitted well with the double exponential and two-stage pseudo-first-order kinetic models. The activation energy of the first stage of the SG dye degradation reaction is 30.45 kJ/mol. GWTW could be re-used for the pre-treatment of dye-contaminated wastewater before entering the wastewater treatment plant.

Sustainable natural coloring potential of bitter gourd (Momordica charantia L.) residues for cotton dyeing: innovative approach towards textile industry.

Natural products particularly natural colorants haveattained worldwide importance and being eco-friendly canbe considered an alternative to toxic dyes in order to reduceenvironmental pollution. The current study is based on the exploration of natural coloring behavior of bitter gourd leaves extract for cotton dyeing. Colorant was extracted using different extraction media like aqueous, alkali, organic, and acidic at different conditions. It has been found that on application of 50ml of acidic extract having 6g/100ml of table salt for 55min at 60 C°, maximum color yield has been obtained onto cotton. Upon using chemical and bio-mordants, new shade with good color fastness rating was obtained. FTIR analysis of extract showed the presence of flavonoids. It is concluded that under mild condition, bitter gourd leaves extract can be considered potential source of natural colorant for cotton dyeing and the presence of bio-mordant has made the process more soothing and sustainable in nature.

A hybrid artificial intelligence model to predict the color coordinates of polyester fabric dyed with madder natural dye

Color matching is an important issue in textile dyeing especially when facing with natural dyes. Generally, the expert engineers evaluate the fabric’s color visually and try different dyeing parameters to achieve that based on the trial and error method and their own experiences. In this study a database was created by evaluating the color of polyester fabrics dyed with madder root at various dyeing conditions using reflectance spectrophotometer. Then, the relations between dyeing parameters and color coordinate values known as l*, a* and b* were analyzed statistically. After that, each color coordinate was modeled separately based on dyeing parameters using linear regression as the old-typical method and artificial neural network (ANN). To increase the ANN model accuracy, the genetic algorithm was implemented to optimize ANN’s parameters. The results indicated that ANNs with two, one and two hidden layers are the accurate predictor tools for l*, a* and b* values, with mean absolute percentage error of 0.67, 1.29 and 1.27, respectively. In the next step, some color coordinates were selected randomly and it was tried to find the corresponding dyeing parameters using multi objective optimization based on the obtained ANN models. A comparison between the actual and obtained dyeing parameters showed the high efficiency of proposed method to determine the dyeing parameters in order to achieve the desired color.

Sustainable isolation of licorice (Glycyrrhiza glabra L.)-based yellow natural colorant for dyeing of bio-mordanted cotton.

Sustainability in the utilization of products in all fields particularly food textiles, solar cells, etc. is of prime concern to the global community. In this study, licorice (Glycyrrhiza glabra L.) as a source of herbal-based coloring agent for cotton dyeing has been explored under the influence of ultrasonic (US) waves. Methanolic extract of licorice bark after US treatment for 20min has shown excellent color depth (K/S) onto ultrasonically treated cotton fabric at 65°Cfor 45min. Applying bio-mordants, it has been found that acacia extract (1%), henna (5%), and pomegranate and turmeric extracts (7%) as pre-bio-mordant, whereas acacia, turmeric, and henna extracts (7%) and pomegranate extract (5%) as post-bio-mordants, exhibited superb color strength. Salts of Al (7%) and salts of Fe (3%) as pre chemical mordants, while salts of Al (3%) and salts of Fe (5%) as post chemical mordants, have given good results. Overall, it has been found that salt of Fe (3%) as pre-chemical mordant and extract of turmeric (7%) as post bio-mordant have shown superb color strength. It can be concluded that US treatment being an environmentally safe means has only improved the color strength of colorant onto cotton fabric and the adding of bio-mordants has contrived the method more sustainable.

Photocatalytic and Photoluminescence Studies of La, Ce, and Dy Co-doped ZnO Nanoflowers

In the present work, ZnO nanoparticles were doped with varying concentration of lanthanum (La), cerium (Ce), and dysprosium (Dy) using a simple and cost-effective co-precipitation approach at low temperatures. The resulting powders were calcined at 500 °C for 1 h using a muffle furnace, to produce La, Ce, and Dy-co-doped ZnO nanoparticles with varying stoichiometry, viz. (Zn0.97La0.01Ce0.01Dy0.01O, Zn0.94La0.02Ce0.02Dy0.02O, Zn0.91La0.03Ce0.03Dy0.03O, Zn0.88La0.04Ce0.04 Dy0.04O, and Zn0.85La0.05Ce0.05Dy0.05O). This is a simple approach for doping and does not require a complex equipment, harmful chemical, or sophisticated machinery. The synthesized powders were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) for studying the structure, purity, and grain morphology. Compositional study was done using EDS (SEM/EDS Hitachi 3600 N). The average crystallite size was calculated using XRD and was found to be 35 nm, and it also indicated a hexagonal wurtizite structure with no secondary peaks. A change in morphology from nanorods to nanoflowers was observed as the concentration of dopants increased. Photoluminescence (PL) spectra indicated a redshift in the absorption edge toward the visible region of solar spectrum and this was further confirmed by diffuse reflectance spectra (DRS). The photocatalytic properties of undoped and La, Ce, and Dy-co-doped ZnO nanoparticles were observed by examining the photodegradation of Rhodamine B dye under UV irradiation. The elimination of dye color indicated the total degradation of organic molecule. The results revealed that ZnO photocatalyst with La, Ce, and Dy co-dopant concentration Zn0.85La0.05Ce0.05Dy0.05O exhibited the best photocatalytic performance (95%) as compared to undoped ZnO. The improved photocatalytic performance can be attributed to the increased surface oxygen vacancies and adsorption capacity. The delay in recombination of charge carriers due to creation trap states in the bandgap of ZnO further improves the photocatalytic performance of doped samples.

High-sensitive colour indicator of absorbed dose of epithermal neutrons radiation

In our study, the high-sensitivity colour indicator of the absorbed dose of radiation of epithermal neutrons with energy 0 to 10 keV for dosimetry of low-energy neutrons was developed. We had been developed an indicator on the basis of the dye solution of arsenazo III and gadopentetic acid, allowing precisely define of absorbed dose in the range 2 to 103 Gy. The properties of arsenazo III as metallic indicator, which changes colour after binding of free ions of metals, were used. Colour of the indicator solution before irradiation and after it is stable enough in time at storage in the dark, at artificial illumination or at scattered sunlight. The developed indicator, consisting of a solution of arsenazo III and gadopentetic acid, allows estimating the absorbed dose of epithermal neutron irradiation with good accuracy and reduces the error of measurement related to changing colour of dye under the influence of other factors (light, temperature etc.) Dosimeter is tissue-equivalent and possesses a high-sensitivity neutron radiation due to the content of gadolinium in solution, which has great neutron capture cross-section. The developed dosimeter persists spectrophotometric characteristics after irradiaion within few weeks that allows to use it for measurement of the absorbed dose, both in real time mode and with the delayed measurement within few weeks.

Pengaruh Tegangan Elektrokoagulasi dan Konsentrasi Awal Pewarna terhadap Persentase Penyisihan Remazol Red RB

Batik industry wastewater has an adverse effect for the environment if disposed without any treatment. Wastewater of batik industry increases as production of batik industri growth. Remazol Red RB is one of the pollutant sources in batik dyeing process wastewater. The conventional method which is used for processing wastewater still has feebleness so as an innovative method wastewater treatment is needed. One ot those is electrocoagulation. Electrocoagulation is colloidal destabilization through an electrochemical process. This electrocoagulation carried out by varying electrical voltages and initial concentration of dyes. Electrical voltages are varied at 10 volt, 15 volt, 20 volt, and 25 volt, initial concentration are 100 ppm, 150 ppm, 200 ppm, and 250 ppm. Percent removal measured for determining the effect of electrical voltage and initial concentration. decreasing dyes color is measured using spectrophotometer UV-Vis. Electrocoagulation process uses aluminum as anode and iron as cathode which is arranged in monopolar series configuration. The wastewater is 200 mL in volume and the process was taken in 60 minutes. Result showed that both of electrical and initial concentration affect percent removal of synthetic wastewater dyes. The best electrical voltage and initial concentration are 25 volt and 100 ppm with percent removal obtained is 99,80% for 10 minutes electrocoagulation.

Ethylene glycol diglycidyl ether applied to crosslinking dyeing of cotton fabric with madder dye

AbstractCotton fabric dyed with natural madder dye exhibits poor dyeing properties. Although mordant improves the dyeing property of cotton fabric, it changes the madder dye colour tonality (the hue angle). In this study, ethylene glycol diglycidyl ether (EGDE) was used as a crosslinking agent to dye cotton fabrics with natural madder dye and improve the surface colour depth (K/S) and colour fastness. The molecular structure, crystal structure and surface morphology of crosslinked dyed cotton were analysed using Fourier Transform–infrared spectroscopy, X‐ray diffractometry and scanning electron microscopy, respectively. The results showed that crosslinked dyed cotton fabric had two different ether bonds, and that crosslinked dyeing mainly occurred in the amorphous area. Compared with direct dyed cotton fabric, the hue angle (h°) of crosslinked dyed cotton fabric did not undergo an obvious change, K/S increased by 5, and the rubbing fastness, washing fastness and light fastness increased by 2‐3 levels, indicating that the dyeing property of cotton fabric with natural madder dye could be improved by using EGDE as a crosslinking agent. Compared with raw cotton fabric, the bending length of crosslinked dyed cotton fabric was reduced by 2.28 cm, the wrinkle recovery angle increased by 80.7° and the ultraviolet protection factor value was more than 40, indicating that crosslinked dyed cotton fabric had great softness, wrinkle resistance and excellent ultraviolet resistance. In addition, the water contact angle of the cotton fabric only changed slightly after crosslinking dyeing, and the crosslinked dyed cotton fabric still had good hydrophilicity. Therefore, EGDE was a viable crosslinking agent for cotton fabric with madder dye.

Evaluation of watermelon peel, banana peel and bay leaves hydrochars as green catalysts in the degradation of malachite green by thermally activated persulfate oxidation method

Water is essential for the continuation of life, moreover, clean water is of great importance on the basis of a healthy life. However, one of the biggest problems of our age is water scarcity and the rapid pollution of existing water resources. Besides, solid food wastes are becoming a growing problem day by day. Therefore, both environmentally friendly, effective and innovative techniques are required in the reuse of solid waste in the treatment of wastewater that is generated at enormous levels. In this study, the thermally activated persulfate (TAP) oxidation method was applied to remove the color and total organic carbon (TOC) of an industrial dye, malachite green (MG). The effects of different levels of experimental variables such as concentration of the oxidising agent, K2S2O8, (0.048 mM–0.55 mM), temperature (336 K–370 K) and treatment time (1.6 min–18.4 min) on the color and TOC removal of MG were investigated. Color removal efficiencies of 97.3% and TOC removal efficiencies of 56.4% were achieved. Evaluation of the effects of the experimental variables on the responses and the optimisation of the TAP method was performed using the response surface method (RSM). The accuracy of the method was assessed by ANOVA. Catalytical efficiencies of hydrochars synthesized in the subcritical water medium (SWM) and obtained from solid food wastes such as banana peel (BP) and watermelon peel (WM) as well as bay leaf (BL) were evaluated. The synthesized hydrochars were characterised by scanning electron microscope (SEM) and (Brunauer–Emmett–Teller) BET analyses. The most effective hydrochar in the catalysis of K2S2O8 was BP hydrochar as 83.6% of color removal was obtained using 0.048 mM K2S2O8 and 2 g/L BP hydrochars at 353 K in 10 min.

A study on natural dyeing of cotton using Cocos Nucifera

Natural dyes are obtained from roots, leaves, barks, fruits and fruit-coat or wood of the plants. It exhibits better bio-degradability and has a better suitability with the environment and its use in coloration of fabric materials is the consequences of increased environmental awareness. The aim of this research work is to extract dye from natural source and perform an experimental analysis of the dye adherence on cotton fabric. The natural source selected for the study is the nonedible portion of cocos nucifera at fresh and dried stages. The dye extraction was carried out using water and methanol. Then the cotton fabric was dyed and analysed for various physical and colour fastness properties. The aqueous extract of green coconut shell on the cotton fabric had good dye adherence and colour fastness. It was observed that the dyed fabrics exhibited good strength and colourfastness properties.

Application of Red Dragon Fruit Dyes as Staining in Histological Study

Background: The betacyanin pigment found in dragon fruit flesh (Hylocereus costaricensis (F.A.C.Weber) Britton & Rose) has many advantages, for instance as a tissue histology dye.
 Objectives: determining the properties of organs stained with betacyanin red dye and finding alternative histology colors to replace synthetic hematoxylin-eosin dyes.
 Summary of contents of the article: The flesh of the red dragon fruit (Hylocereus costaricensis (F.A.C.Weber) Britton & Rose) was extracted using the Ultrasonic Assisted Extraction (UAE) method. The study employed six male white mice divided into two treatment groups: a placebo group induced with 1% Na.CMC carrier solution and a positive control group generated a toxic dose of paracetamol. The results were visually compared to hematoxylin-eosin with standard betacyanin and betacyanin extract of red dragon fruit flesh concentrations of 50% (v/v), 80% (v/v), and 100% (v/v).
 Conclusion: Betacyanin from the flesh of the red dragon fruit can be applied as a histological dye in the liver of male white mice and as a counterstaining hematoxylin as a substitute for eosin dye at a concentration of 100% (v/v).

Polymer Nanoparticle-Based Spherical Photonic Pigments for Dye-Free Noniridescent Bright Coloring

While the color of conventional pigments and dyes is related to the absorption of light, structural color results from selective light scattering by nanostructures with an appropriate periodic vari...

Standardization of resazurin use in susceptibility testing of natural products against yeasts in planktonic cells and in biofilms formation

Natural products, such as the ethanolic propolis extract (PE), have been shown to be a safe and effective therapeutic alternative for the treatment of fungal skin and nail diseases. However, the presence of the resin and the physicochemical characteristics of the extract sometimes difficult the reading and determination of breakpoints of the in vitro tests, evidencing the need for alternatives that facilitate the reading. The present study aimed to standardize the use of resazurin in tests of susceptibility of PE with planktonic yeast cells and biofilm forms. The antifungal activity of PE was determined by minimum inhibitory concentration (MIC) and we observed that, for all Candida spp. tested, the most reproducible MIC results were obtained when resazurin was placed after 24 hours of incubation and remained more 24 hours with yeasts plus PE. For encapsulated yeasts, there was no dye reduction and color transition. Resazurin was also used for the evaluation of minimal biofilm inhibitory concentration and minimal biofilm eradication concentration and it was metabolized and reproduced the action of PE on Candida biofilms. In addition, microdilution checkerboard plates were made with the dye, which assisted reading the result of the interaction between PE and nystatin. We observed that the resin, the color and the turbidity of the PE slightly changed the color of the resazurin in high concentrations of the extract and did not impair the reading. Therefore, the resazurin standardization tests were proven to be efficient and grounds that it should be used as an auxiliary methodology for reading and interpretation of the susceptibility tests for non-encapsulated yeasts with natural products, which form turbidity or precipitation, such as propolis.

Waste black tea leaves (Camelia sinensis) as a sustainable source of tannin natural colorant for bio-treated silk dyeing.

Environmentally friendly products are the need of the hour, particularly in this pandemic situation because synthetic products need such toxic chemicals for their formulation and finishing which are carcinogenic for the globe. The current study is the utilization of waste black tea leaf (BT)-based tannin brown natural colorant for silk dyeing using microwave treatment. Dye (tannin) has been isolated in various media before and after microwave treatment up to 6 min and applied at various conditions. It has been found that 30 mL of aqueous extract of 3.0 pH obtained from 6.0 g of powder containing 3.0 g/100 mL of salt as an exhausting agent after microwave treatment for 5 min, when employed at 55 °C for 45 min, has given good color yield onto silk. Iron (3%) and acacia extract (2%) as pre-chemical and bio mordant, iron (2%) and pomegranate extract (2%) as post chemical and bio-mordant, and Al (3 %) and pomegranate extract (3%) as meta chemical and bio-mordant have given new shades with good to excellent fastness ratings. It is inferred that waste black tea leaves (BTs) in an aqueous medium have an excellent potential to serve as a source of natural tannin brown dye for the coloration of surface-modified silk fabrics under the influence of cost, energy, and time-effective microwave treatment. Additionally, the utilization of a low amount of sustainable chemical and bio-mordants has valorized the dyeing of silk by developing soothing and sustainable shades with good fastness properties.

Electrospun Ultrafine Cationic Cellulose Fibers Produced from Sugarcane Bagasse for Potential Textile Applications.

Sugarcane bagasse (SCB) is an abundant by-product of sugar refining that can be utilized as a raw material for cellulose isolation for several industrial applications. Electrospinning has garnered attention in recent years because it allows the preparation of cellulosic materials with unique properties. In this study, cellulose was isolated from sugarcane bagasse and acetylated to fabricate fine acetate cellulose fibers through electrospinning. Subsequently, the electrospun fibers were deacetylated and cationized in order to produce functionalized materials with potential textile applications. The functional fibers were colored with an anionic dye (vinyl sulfone) with and without the presence of salt and were evaluated according to dye fixation, color attributes, morphological characteristics, and thermal stability. Cationic cellulose fibers that were dyed without added salt were found to be brighter and demonstrated better color fixation than those with added salt. In addition, morphological analysis performed using scanning electron microscopy demonstrated that cationized fibers dyed without added salt were better preserved at this stage. The cationic fiber also evidenced a high-temperature resistance, exhibiting a degradation temperature above 236 °C. The results suggest that cellulose fibers dyed in this manner can potentially be considered for use in textile applications due to their suitable dye fixation and tunable porosity (i.e., breathability).

In situ utilization of biomass pretreatment liquor as a novel flocculant for anion dyes removal: Performance and mechanism

In this work, it was first found biomass pretreatment liquor (PL) produced from rice straw (RS) pretreatment with FeCl3 and polyethylene glycol 400 co-solvent can be used in situ as a new flocculant to remove anionic dyes from wastewater. The removal performance of nine dyes was investigated using various PL doses at different pH values. The experiment indicated that the PL had different flocculation effects on these dyes (color removal efficiency: 42.58–99.84%). Positive color removal results for the dyes were unachievable with six commercial coagulants. Among the nine dyes treated by PL flocculation, the best removal efficiencies for color, turbidity and suspended matter were obtained for Congo red. In the flocculation process, Fe3+ plays a role in charge neutralization, lignin nanoparticles (LNP) relies on hydroxyl groups to react instantaneously with the amino groups on the dye, and are bridged together by π–π interactions to promote the formation of floc clusters until they completely settle. Utilization of PL as a flocculant helps pave the way to simultaneously treat waste biomass, waste treatment liquor and dye wastewater. This research is of great significance for future water environment remediation and material development.

Equilibrium kinetic and isotherm studies of dye colour adsorption on the banana peel

Textile, paper, rubber, plastics, leather, cosmetics, pharmaceuticals, and food industries extensively employ dyes. This study aims to determine the best equilibrium kinetic and isotherm model of dye colour adsorption using waste adsorbent. Methylene blue (MB) is a dye colour contaminant that can be removed from wastewater via adsorption due to its ease of usage and cost-effectiveness. This study employed banana peels (BPs), a low-cost and waste adsorbent, to remove MB from synthetic wastewater. A series of batch equilibrium adsorption studies investigated the effect of different dosages of 0.05 to 0.4 grams, contact time of 15 to 150 minutes, and agitation speed of 150 rpm. BPs dosage is added from 0.05 g to 0.4 g in 100 ml of Methylene Blue solution. The concentration of MB in the samples was determined using a HACH DR2800 Spectrometer. According to the kinetic study analysis, the adsorption of MB followed a pseudo-second order kinetic with an R2 of 0.9934. Furthermore, the Freundlich model fit better than others based on the equilibrium isotherm investigation, with an R2 of 0.7688. As a result, BPs can be used as an alternative waste adsorbent media for extracting dye colours from industrial effluent.

Spectrophotometric determination of atenolol via oxidation and bleaching color reaction for methyl red dye

A selective and sensitive spectrophotometric method has been suggested for the quantitative assay of atenolol (ATNL) as pure and in its manufactural formulation(Tablet). The suggested procedure included oxidation of ATNL with an excess quantity of the oxidant N-bromosuccinimide (NBS), and then the excess of NBS was occupied in bleaching the color of methyl red dye(MRD), then measuring the absorbance of remaining MRD at 518 nm. The absorbance of the unbleached color of MRD corresponds to the ATNL concentration in the sample solution. Beer’s law was followed in the range of 0.1-2.0 μg.ml−1with molar absorptivity value equal to 8.8864x104 l.mol−1. cm−1. The suggested method was applied to the assay of ATNL in commercial tablets, with satisfactory results.

Microfluidic chip of concentration gradient and fluid shear stress on a single cell level

Concentration gradient and fluid shear stress (FSS) for cell microenvironment were investigated through microfluidic technology. The Darcy–Weisbach equation combined with computational fluid dynamics modeling was exploited to design the microfluidic chip, and the FSS distribution on the cell model with varying micro-channels (triangular, conical, and elliptical). The diffusion with the incompressible laminar flow model by solving the time-dependent diffusion–convection equation was applied to simulate the gradient profiles of concentration in the micro-channels. For the study of single cell in-depth, the FSS was investigated by the usage of polystyrene particles and the concentration diffusion distribution was studied by the usage of different colors of dyes. A successful agreement between model simulations and experimental data was obtained. Finally, based on the established method, the communication between individual cells was envisaged and modeled. The developed method provides valuable insights and allows to continuously improve the design of microfluidic devices for the study of single cell, the occurrence and development of tumors, and therapeutic applications.

Solvatochromic Fluorescence of a GFP Chromophore-Containing Organogelator in Solutions and Organogels.

Solvatofluorochromism, a solvation effect on the fluorescence color of an organic dye, is a property generally limited to fluid solutions. We demonstrate herein the concept of solid-state solvatofluorochromism by using an organogelator (1-SG), which consists of a solvatofluorochromic green fluorescence protein (GFP) chromophore (1) and a sugar gelator (SG). While 1-SG could be located in the liquid phase or in the fibrous solid matrix of the SG gel, our results show that the one in the solid matrix but near the liquid interface has superior fluorescence stability and quantum efficiency as well as solvatofluorochromicity than the one in the liquid phase. In addition, the phenomenon of fluorescence turn-on occurs when the gel is formed in protic solvents. These features have been applied to perform multicolor fluorescence patterning, chemical vapor sensing, data encryption and decryption, and real-time fluorescence cell imaging.