Mordant Research Articles

Research on the application of biological mordant dyeing with natural dyes

With the continuous development of society, the dyeing and finishing field is transitioning towards green sustainability and multifunctionality. The main direction is to dye fabrics using natural dyes with the aid of mordants. In recent years, the technology of biological mordant dyeing with natural dyes has become a research hotspot. This paper first discusses in detail the application of biological mordant technology with natural dyes on various types of dyed fabrics, including plant fibers, animal fibers, and synthetic fibers. It then introduces the application of biological mordant dyeing with natural dyes in fields such as antibacterial and ultraviolet protection. By comparing the environmental impact and effectiveness of metal mordants versus biological mordants on dyed fabrics, the most suitable mordant is identified. Finally, the paper provides an outlook on the optimization of the dyeing process, in-depth exploration of mechanisms, rational selection of resources, and functional application trends of biological mordant technology with natural dyes, aiming to provide a reference for research directions in this field.

Study on the dyeing properties of Chinese fir with Cinnamomum camphor pigment by premordant dyeing

ABSTRACT Wood staining can improve the quality of Chinese fir. In this study, Cinnamomum camphora natural plant pigment was used as a substitute for synthetic dyes to stain Chinese fir, and the staining performance was enhanced through pre-mordanting with alum. The dyeing effects of direct dyeing and mordant dyeing were compared, and the factors and levels influencing color difference, wash fastness, and light fastness were investigated through an orthogonal experimental design. The results showed that mordanting time had the greatest influence on color difference and lightfastness, while mordanting temperature had the greatest influence on washfastness. After pre-mordanting, the washfastness of Chinese fir improved to a level of 2–3, while the improvement in lightfastness was not significant. Pre-mordanting increased the dye uptake rate by 6.67%. Scanning electron microscopy revealed that NaOH pretreatment opened the wood pores and increased the flow channels for dye liquor. Infrared analysis indicated that O-H in wood fibers formed complexes with Al3+ in the mordant, resulting in a decrease in the characteristic peak intensity of O-H. X-ray diffraction analysis showed that the attractive effect of Al3+ vacant orbitals on O-H partially influenced the ordered arrangement structure in the crystalline region.

Experimental and Theoretical Study of Madder-Associated Dyestuffs on Silk: Adsorption of Kinetics, Thermodynamics and Molecular Docking

ABSTRACT In this work, dyed samples were self-prepared from two methods including madder dyeing and mordant dyeing by madder combined with Al3+ at different temperatures, and their kinetics and isothermal adsorption were both discussed. Weber–Morris diffusion model and Freundlich model were found to be more suitable in dyeing for kinetics and thermodynamics. Through SEM, FTIR and fastness tests, the dyeing performances were displayed and the possible structure between madder dyes and the complex with Al3+ were illustrated. By molecular docking, madder dyes showed combination with glutamic acid predominantly. After introducing metal ion, the shortage of hydrogen bonds length was observed. It was initially employed to elucidate the potential binding modes between dyes and proteinaceous fibers. Overall, through experimental dyeing and curve fitting, this study provided insights into the dyeing mechanism of madder-associated dyestuffs on silk. Moreover, molecular docking elucidated the dyeing mechanism further, highlighting that the presence of metal ion enhances the firmness of the staining. The elucidation of dyeing mechanism not only provided valuable theoretical support for color restoration but also shed light on the practically modify of methods in obtaining ideal color. These results could serve as inspiration for conservators to maintain the vibrancy and longevity of dyed silks.

Utilization of Tamarind Seeds Extract as a Natural and Sustainable Fabric Dye

This research focuses on the use of tannin components in tamarind seed coats as a mordant and natural dye in cotton fabrics. Tannins were extracted from the tamarind seed coat by boiling method and then the tannin content was determined. The tannin extract was then used as a natural mordant with the addition of metallic copper sulfate (CuSO4) mordant. Tannin extract is also used as a dye on fabrics with the addition of sodium sulfate (NaSO4). The color strength of the tannins in the fabric was analyzed using a spectrophotometer from the rinse water. The results showed that the cloth that had been given the mordant had a stronger color strength than the cloth without the mordant. The use of mordant was varied at concentrations of 5, 10, 15, 20, and 25%-owf. The results of the analysis showed the most optimum tannin concentration at 15%-owf. The concentration of tannin used in the coloring process was also varied at concentrations of 5, 10, 15, 20, and 25%-owf. The results of the analysis show that the concentration of tannin used in the dye does not affect the strength of the color, but only affects the brightness of this color.

Hydrothermal synthesis of Mg/Al-layered double hydroxide modified water hyacinth hydrochar for remediation of wastewater containing mordant brown dye.

A high-performance dye adsorbent of Mg/Al-layered double hydroxide modified water hyacinth hydrochar (MgAl@WH) was synthesized by a simple hydrothermal method. The surface functional groups, elemental composition, crystalline structure, and surface morphology of the prepared (MgAl@WH) were determined using different analytical techniques. The characterization results revealed that the (MgAl@WH) hydrochar surface offered more active adsorption sites, facilitating the mordant brown (anionic dye) adsorption, leading to its superior performance with much higher uptake capability (311.0 mg g-1 at 298 K) than Mg/Al double hydroxide nanosheets (MgAl DLHs, 80.2 mg g-1 at 298 K) and dried water hyacinth (WH, 10.0 mg g-1 at 298 K). The adsorption behavior of MgAL@WH follows the pseudo second order kinetic model (R2 = 0.999) and Langmuir isotherm model (R2 = 0.999). Moreover, MgAl@WH bonded efficiently with mordant brown dye via hydrogen bonding and interlayer anion exchange with monolayer formation. Additionally, the recycling tests revealed that the MgAl@WH can be reused over 10 cycles without significant change in the removal efficiency. Based on the obtained findings, Mg/Al-layered double hydroxide modified water hyacinth hydrochar (MgAl@WH), for its economic and environmental benefits, has recently been used as an efficient adsorbent to remediate industrial wastewater containing anionic dyes.

Biosynthesis and Stabilization of Nanosilver Using Houttuynia Extract for Degradation of Azo Acid and Mordant Dyes

Silver nanoparticles (AgNPs) are promising candidates for environmental remediation due to their exceptional catalytic properties. However, their tendency to aggregate during formation undermines their stability, posing challenges for large-scale production. This study presents a one-step biosynthesis method of AgNPs using Houttuynia plant (Houttugniae herba) extract, where the plant biomolecules act as both reducer and stabilizer. The bioreduction kinetics were meticulously optimized using the one-factor-at-a-time (OFAT) approach, establishing the ideal synthesis conditions as follows: 1.0 mM AgNO3, 0.1 ml Houttuynia plant extract, heated at 80 °C for 45 minutes, with the medium at pH 9. Morphological characterization revealed the formation of spherical, well separated, and highly crystalline (d-spacing = 0.237 nm) AgNPs with an average particle size of 7.756 ± 2.372 nm. The synthesized AgNPs exhibited remarkable catalytic activity in reducing azo dyes, achieving degradation rates of approximately 98% for both acid red 1 (AR1) and mordant blue 9 (MB9) within 4 and 20 minutes, respectively. This eco-friendly and cost-effective method can be an excellent alternative for treating industrial effluents.

Natural deep eutectic solvent: A novel and green mordant for the natural dye

Applying natural dye is a green and available approach for the dyeing and simultaneous functionalizing of textiles. However, the commonly used mordant of metal ions to improve the dyeing effect results in massive toxic wastewater production, which decreases the environmentally friendly characteristics. In this work, the mordant and water substitute ability of choline chloride-ethylene glycol natural deep eutectic solvent (NADES), defined as the mixture of two or more primary metabolites at a particular composition becoming liquids via H-bond forces, was investigated during the dyeing process because it has been used as a green extraction and stability agent for the natural dye. To this end, the NADES and metal ion were used in three mordant dyeing wool and cotton processes of Platycodon Grandiflorus root dye, and the color and functionalization effect were compared to verify the method advance. The result indicated that natural deep eutectic solvent had a better effect as a mordant than the metal ion by enhancing the dye solubility, the dye uptake rate of fiber, and the dye polymerization trend via rich H-bonds among fiber, dye, and NADES. The dyed textile had an excellent functional performance, including UV resistance, antibacterial, antioxidation, and burning difficulty, with the preferable fastness. This method also showed good universality for other natural dyes and NADESs. Compared to the existing mordant dyeing technologies, the proposed technology had lower chemical reagent usage, cost, and energy consumption, whose residual solvent had good reusability for at least 10 times and better degradability. Overall, this paper supplied a potential and green approach using NADESs as alternatives to metal ions for the mordant dyeing textile using natural dye.

Wood Colouring with Natural Dye Extracts. New Research and Perspectives

The aims of the present research were to test new types of natural dye extracts for wood as a possible alternative to synthetic dyes and to evaluate the colour changes after a period of one year of exposure to natural light, in indoor conditions. Three types of extracts using raw materials: nutshell from Juglans regia L. (E1), onion peels (E2), and dry plant of Chelidonium majus L. (E3) were employed. Spruce wood (Picea abies L. Karst) samples with dimensions of (120x80x5) mm were used. The dye aqueous solutions with a concentration of 5% (E1, E3) and 2.5% (E2) were obtained by solid-liquid extraction at 100°C for three hours. The extracts E1, E2, E3 were modified by the addition of mordant ferrous sulphate Fe2(SO4)3 3% and coded EM1, EM2, EM3 respectively. The wood was coloured by dipping procedure at 60° C for 30 min. Three replicates were employed for each type of dye solution. After conditioning, two replicates together with the uncoloured samples (M) were further exposed indoors, and one coloured sample remained unexposed, as a control. Colour measurements in the CIELab system were performed before and after each period of exposure (30, 60, and 365 days), and the colour differences ΔL, Δa, Δb, and ΔE were calculated. Generally, all the samples dyed with natural extracts had fewer colour differences compared with the uncoloured wood. The lower value for colour change was registered for the E2 extract, followed by the E3, and E1 extract, respectively. According to the exposure time, the colour differences values ΔE range correspond to a medium colour up to different colours in visual perception. For mordant dye extracts EM1, EM2, and EM3 the results indicated a different colour in visual perception. The ΔE values registered were even higher than the uncoloured samples (M). The results were in accordance with similar research in the field. The present study opens new research opportunities in wood finishing and new colouring perspectives with eco-friendly dyes.

Amine-Functionalized MWCNTs for the Removal of Mordant Black 11 Dye

In this study, amine-functionalized MWCNTs (f-MWCNTs) have been investigated as potential material for the removal of Mordant black dye 11 (MBD 11). To evaluate the optimal condition and adsorption capability of the adsorbents (f-MWCNTs), the effect of temperature, pH, adsorbent dosage, and contact time on adsorption rate are examined. The study shows a stronger interaction between the dye and f-MWCNTs. The highest removal efficiency is observed in acidic medium (pH 2) with an initial dye concentration of 50 mg L−1, where 99% of the dye is adsorbed from the medium in 40 min using 0.05 g of f-MWCNTs. Adsorption isotherm and kinetic studies reveal that adsorption occurs by the Langmuir adsorption model and pseudo-second-order adsorption kinetics. According to the thermodynamic parameters, the adsorption exhibits endothermic and spontaneous behavior.Graphical

Sustainable dyeing of mulberry silk fabric using extracts of green tea (Camellia sinensis): Extraction, mordanting, dyed silk fabric properties and silk-dye interaction mechanism

Sustainability and environmental awareness had an impulse in increasing the global interest to utilize the industrial crops for producing new colouring shades in place of hazardous synthetic dyes. The present research focuses on extracting functional components from green tea (Camelia sinensis) leaves using water and methanol/water solvent systems and their application in the mordant dyeing of mulberry silk fabrics. The effect of pH was studied to maximize the yield of total polyphenols, flavonoids, and antioxidant properties of the solvent extracts. Compared to the unmordanted dyed silk, the mordant dyeing of silk with tea extracts at a temperature of 80 ℃ for 45 min resulted in significant improvements in various color properties. These enhancements include the shade, color strength (K/S), color coordinates, and fastness properties of the dyed silk fabric. Mordant dyeing of silk fabric enhanced UV protection and antimicrobial activities as well. The bonding properties of tea polyphenols on silk was well demonstrated with the help of X-ray photoelectron spectroscopy (XPS). To establish the mechanism of dyeing, catechin was used as a standard and mordant dyeing in silk, resulting in similar golden-yellow coloration. It shows identical properties with the silk dyed with tea extracts resulting in the fact that catechins are the responsible components in silk dyeing while using tea extracts. Theoretical interaction energy (Einteraction = −13.836 kJ/mol) calculation established good stability of mordanted catechin dyeing on silk, and catechin stability in different solvents were in the order catechin-water > catechin-methanol > catechin-ethanol. This work suggests that the mulberry silk fabrics dyed with green tea extract showed diverse color variations, which is highly promising to be used as a natural dye in the textile industry.

Treatment of textile wastewater using carbon-based nanomaterials as adsorbents: a review.

Waste derived from the textile industry can contain a wide variety of pollutants of organic and inorganic natures, such as dyes (e.g., acid, basic, reactive, mordant dyes) and toxic metals (e.g., lead, chromium, cadmium). The presence of pollutants at high concentrations in textile waste makes them relevant sources of pollution in the environment. To solve this problem, various technologies have been developed for the removal of pollutants from these matrices. Thus, adsorption emerges as an efficient alternative for textile waste remediation, providing advantages as simplicity of operation, economy, possibility of using different adsorbent materials, and developing on-line systems that allow the reuse of the adsorbent during several adsorption/desorption cycles. This review will initially propose an introduction to the adsorption world, its fundamentals, and aspects related to kinetics, equilibrium, and thermodynamics. The possible mechanisms through which a pollutant can be retained on an adsorbent will be explained. The analytical techniques that offer valuable information to characterize the solid phases as well as each adsorbate/adsorbent system will be also commented. The most common synthesis techniques to obtain carbon nano-adsorbents have been also presented. In addition, the latest advances about the use of these adsorbents for the removal of pollutants from textile waste will be presented and discussed. The contributions reported in this manuscript demonstrated the use of highly efficient carbon-based nano-adsorbents for the removal of both organic and inorganic pollutants, reaching removal percentages from 65 to 100%.

Iron overload induced by diphenylamine triggers reactive oxygen species and apoptosis in the spleen of pregnant rats and their fetuses.

Diphenylamine (DPA) is an aniline derivative, used widely as an industrial antioxidant, dye mordant, and agricultural fungicide. DPA was reported as hazardous to mammals both acutely and chronically, however little is known about the toxicity of DPA and its derivatives during pregnancy. This study aimed to evaluate and explain the possible mechanism of toxicity induced by DPA on blood and spleen, as a fundamental hematopoietic target organ, in pregnant rats and their fetuses. Pregnant rats were orally administrated distilled water, corn oil, and/or DPA (400 mg/kg b.wt) from the 5th to 19th day of gestation. DPA-induced spleen toxicity was mirrored by significant upregulation of programmed death-1 (PD-1) protein expression and an increase in the percentage of apoptotic cells and a decrease in their proliferating capacity. These results have been confirmed through marked G0/G1 cell-cycle arrest that was observed by flow cytometric analysis of spleen cells. Moreover, the contents of reactive oxygen species and iron in the spleen tissue were significantly higher than that of the control group. DPA resulted in severe anemia, decreased hemoglobin and hematocrit, thrombocytopenia and leukopenia in addition to significant changes in differential leukocytic count of both mothers and fetuses. Evidently, DPA triggered serious pathological changes in the spleen tissue of both mothers and fetuses and the histochemical examination revealed a significant increase in iron expression. In conclusion, these results implicate the hemato- and splenotoxicity of DPA and the possible role of oxidative stress and apoptosis in DPA-induced toxicity in the spleen of pregnant rats and their fetuses. This in-turn suggests the urgent need to reduce exposure to DPA as possible as it can.

Ecofriendly hair dye extraction from wastewater pericarp processing by-products of water caltrop (Trapa quadrispinosa): Optimization and evaluation

As an alternative approach for toxicological effects of synthetic hair dyes, water caltrop (Trapa quadrispinosa) pericarp pigment extracted by 50% ethanol at 40 °C for 30 min was used as an ecofriendly and natural hair dye. Water caltrop pericarp (WCP) of seven regions were experimented to develop eco-friendly dyes intended for application in alternative chemical synthesis hair dyeing products. The results showed that the highest content of polyphenol was extracted from WCP in Jiaxing, which was used as a follow-up study. The optimization method was mordant dyeing first and then dyeing. Optimal dyeing conditions were identified as 4% Fe3+ at 25 °C with a total dyeing time of 65 min, and WCP hair dye showed better resistance to washing. The results of SEM and DSC showed that WCP hair dye could replace synthetic hair dyes and has some restorative function for damaged hair. This study provides a valuable reference for the development of more environmentally friendly hair dyes.

Dye removal from simulated and real textile effluent using laccase immobilized on pine needle biochar

Textile industries generate huge amount of water containing harmful azo dyes that have known carcinogenic and mutagenic toxicities. Removal of these azo dyes is an important step in the treatment of wastewater. This work evaluates the potential application of enzyme immobilized biochar for the removal of azo dyes from real and simulated textile effluents. The simulated textile effluent was prepared using azo dyes Congo red, Malachite green and their mixture. Dye removal studies were conducted in batch studies using laccase immobilized biochar and optimization of immobilization was achieved through response surface methodology. In the case of simulated effluent, higher dye removal efficiencies were obtained when added separately (73.8 % for Malachite green dye and 88.1 % for Congo red) in comparison to when mixed together (59.3 % for Malachite green dye and 78.7 % for Congo red). In the case of real textile effluent, the dye removal through an enzyme immobilized system with 100 % removal efficiency was obtained for one of the dye peaks while it was 35.7 % for the other dye present in the effluent along with 33.3 % COD removal. The real textile effluent was analyzed by GC–MS and the presence of one of the metabolite phenol,2,4-bis (1,1-dimethyl ethyl) in the GC–MS spectra indicated degradation of dye Mordant Black. Thus, an enzyme immobilized biochar system can be used for simultaneous dye adsorption and degradation of toxic azo dyes from real effluents.

Nature dye/nanosphere dispersion with high light stability and colorability for cellulose fabric

Monodisperse poly (methyl acrylate-meth-acyloxy-ethyl trimethylammonium chloride) cationic nanospheres were synthesized by soap-free emulsion polymerization, and were subsequently combined with gardenia to prepare dye/nanospheres. The influence of the concentration of gardenia yellow, rate of vortexing, temperature and pH of mixing on the adsorption capacity and stability of microspheres were thoroughly investigated, and the prepared gardenia/poly (methyl acrylate-meth-acyloxy-ethyl trimethylammonium chloride) nanospheres acted as liquid pigments to dye the fabric substrates by the impregnation method. In particular, the photostability of gardenia/poly (methyl acrylate-meth-acyloxy-ethyl trimethylammonium chloride) and the reflection of its dyed fabrics are distinctly described, the comparison of the dyeing property effect between gardenia/poly (methyl acrylate-meth-acyloxy-ethyl trimethylammonium chloride) and gardenia yellow dyed by mordant dyeing were analyzed. According to the experimental findings, the dyestuff nanospheres have high stability when the pH is 7–8, the mass ratio of gardenia yellow to poly (methyl acrylate-meth-acyloxy-ethyl trimethylammonium chloride) nanospheres was 12.8:1, the temperature was 60°C for 30 min, and the mixing speed was 500 rpm. Dyeing cotton fabrics with gardenia/poly (methyl acrylate-meth-acyloxy-ethyl trimethylammonium chloride) produced higher color strength and color fastness than the gardenia yellow with mordant dyeing.

Cetylpyridinium chloride cationic finishing improves the dyeing and antibacterial properties of madder dyed cotton

AbstractIn this work, after cationic pretreatment of cotton fabric with cetylpyridinium chloride (CPC), the compound of citric acid (CA) and succinic acid (SUA) were used as crosslinking agents to dye cotton fabrics with natural madder dye to improve the dyeing and antibacterial properties and realise the multifunctional finishing of cotton fabric. The effects of mordant dyeing, CA + SUA crosslinked dyeing, and CPC/CA + SUA crosslinked dyeing on the microstructure and properties of cotton fabrics were compared. The dyeing by the three processes occurred primarily in the amorphous zone of the fibres, and all kept the original crystalline form of the cotton. CA + SUA crosslinked dyeing and CPC/CA + SUA crosslinked dyeing increased the thermal stability of the cotton fabric. CPC/CA + SUA crosslinked dyed cotton obtained excellent dyeing results with the colour depth value (K/S) of 12.3 and rubbing fastness and washing fastness of levels 4–5, and the levelness and dye permeability were acceptable. Furthermore, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99.99%, and the ultraviolet protection factor (UPF) reached 50+. Moreover, the wrinkle recovery angle (WRA) increased by 55% compared with raw cotton. This showed that CPC/CA + SUA crosslinked dyed cotton had excellent antibacterial, anti‐ultraviolet, and anti‐wrinkle performances.

Molecular modeling of mordant black dye for future applications as visible light harvesting materials with anchors: design and excited state dynamics

In this study, new visible light harvesting dyes (MBR1-MBR5) have been designed as efficient materials with silyl based anchoring abilities on semiconducting units for future dye-solar cells applications. Their unique molecular structures of novel D-π-ASemiconductor typewere evaluated thoroughly by density functional theory (DFT) calculations. To enhance the optical performance in visible region, a novel dye structure (MBR) was derived from the chemical structure of mordant black (MB) dye with electron acceptor semiconducting units (MBR1-MBR5). The Coulomb-attenuating Becke, 3-parameter, Lee-Yang-Parr (CAM-B3LYP) functional, which had a hybrid and long-range correlation with 6-31G + (d,p), generated a [Formula: see text] (683nm) that was very comparable to its experimental value (672nm). The energies of highest occupied molecular orbitals (HOMO), lowest unoccupied molecular orbitals (LUMO), and their HOMO-LUMO energy gaps (HLG) were calculated. Their ionization potentials (IP) varied from 5.616 to 8.320eV, demonstrating their good electron donating trend. The [Formula: see text] values of dyes displayed a significant red shift from MBR (682nm) value with range 565-807nm except MBR1 which was slightly blue shifted. The dye MBR4, which had the smallest HLG (0.23eV) had the greatest second order nonlinear optical (NLO) response of 144,234 Debye-Angstrom-1. The DFT calculated results provided insight into the creation of new silyl anchoring groups for future DSSCs material designs with increased stability and effectiveness. The goal of the current study is to forecast the development of novel NLO materials with a D-π-ASemiconductor design that use semiconductors as anchoring groups to adhere to a surface.

A Comparison of Different Reagents Applicable for Destroying Halogenated Anionic Textile Dye Mordant Blue 9 in Polluted Aqueous Streams

This article aimed to compare the degradation efficiencies of different reactants applicable for the oxidative or reductive degradation of a chlorinated anionic azo dye, Mordant Blue 9 (MB9). In this article, the broadly applied Fenton oxidation process was optimized for the oxidative treatment of MB9, and the obtained results were compared with other innovative chemical reduction methods. In the reductive degradation of MB9, we compared the efficiencies of different reductive agents such as Fe0 (ZVI), Al0, the Raney Al-Ni alloy, NaBH4, NaBH4/Na2S2O5, and other combinations of these reductants. The reductive methods aimed to reduce the azo bond together with the bound chlorine in the structure of MB9. The dechlorination of MB9 produces non-chlorinated aminophenols, which are more easily biodegradable in wastewater treatment plants (WWTPs) compared to their corresponding chlorinated aromatic compounds. The efficiencies of both the oxidative and reductive degradation processes were monitored by visible spectroscopy and determined based on the chemical oxygen demand (COD). The hydrodechlorination of MB9 to non-chlorinated products was expressed using the measurement of adsorbable organically bound halogens (AOXs) and controlled by LC–MS analyses. Optimally, 28 mol of H2SO4, 120 mol of H2O2, and 4 mol of FeSO4 should be applied per one mol of dissolved MB9 dye for a practically complete oxidative degradation after 20 h of action. On the other hand, the application of the Al-Ni alloy/NaOH (100 mol of Al in the Al-Ni alloy + 100 mol of NaOH per one mol of MB9) proceeded smoothly and seven-times faster than the Fenton reaction, consumed similar quantities of reagents, and produced dechlorinated aminophenols. The cost of the Al-Ni alloy/NaOH-based method could be decreased significantly by applying a pretreatment with Al0/NaOH and a subsequent hydrodechlorination using smaller Al-Ni alloy doses. The homogeneous reduction accompanied by HDC using in situ produced Na2S2O4 (by the action of NaBH4/Na2S2O5) was an effective, rapid, and simple treatment method. This reductive system consumed quantities of reagents that are almost twice as low (66 mol of NaBH4 + 66 mol of Na2S2O5 + 18 mol of H2SO4 per one mol of MB9) in comparison with the other oxidative/reductive systems and allowed the effective and fast degradation of MB9 accompanied by the effective removal of AOX. A comparison of the oxidative and reductive methods for chlorinated acid azo dye MB9 degradation showed that an innovative combination of reduction methods offers a smooth, simple, and efficient degradation and hydrodehalogenation of chlorinated textile MB9 dye.

Black Plum Fruit Extract as a Substitute for Haematoxylin in Haematoxylin and Eosin Staining Technique

Natural dyes are employed for staining various histological tissues, which serve as a significant alternative source for synthetic dye, thereby reducing the burden of buying synthetic dyes and its impact on the environment. This study aimed to extract the black plum plant (syzigium cumin) using an aqueous solvent and investigate its staining properties in the albino rat kidney tissue section. The Extract was allowed to evaporate at 55⸰ C. The proportion of black plum is 3:1(black plum extract: solvent v/v) in two places, and a mordant was added to the first part. The rat kidney tissue was processed for paraffin-embedded at a thickness of 5 micron. The black plum dye was used to stain the section for 10 minutes with potassium alum as mordant and without potassium alum. The result revealed that the Extract of black plum stained the nuclei purple and the cytoplasm pink by the eosin when compared with the control hematoxylin and eosin staining technique. The optimal stain was from the mordant black plum dye. The findings suggest that Extract from black plum has dye properties that can serve as an alternative for Haematoxylin in Haematoxylin and eosin staining techniques.

Microwave‐Induced Synthesis of Pyridine Based Schiff Bases and Their Applications as Efficient Antimicrobial Textile Dyeing Agents: Experimental and Theoretical Approach

AbstractThree new pyridine‐based Schiff bases P‐2IMBT ((Z)‐2‐(((pyridin‐2‐ylmethyl)imino)methyl)benzene‐1,3,5‐triol), P‐3IMBT (Z)‐2‐(((pyridin‐3‐ylmethyl)imino)methyl)benzene‐1,3,5‐triol, and P‐4IMBT 2‐(((pyridin‐4‐ylmethyl)imino)methyl)benzene‐1,3,5‐triol were investigated to see if they could be employed as antimicrobial textile synthetic dyes. Adding the pyridine nucleus to these compounds improves their textile colour and therapeutic potential. Microwave‐assisted synthesis was used to synthesize these molecules, which is highly efficient, safe, cost‐effective, and ecologically benign. NMR, IR, Mass, PXRD, UV‐Vis, DFT calculations, Fluorescence, and thermogravimetric methods were used to describe all of the compounds. In experiments on wool and silk, these positional isomers, P‐2IMBT, P‐3IMBT, and P‐4IMBT, were found to be washable and offered a rich brown hue with good tonal variation. Cotton had to be pre mordanted, and this is likely a one‐of‐a‐kind cotton mordant dye. Further antimicrobial studies suggest that these compounds could be effective antibacterial agents.