The document discusses using iron(II) salt complexes as reducing agents for dyeing cotton with vat dyes as an alternative to sodium hydrosulfite. Single ligand systems of iron(II) complexes were ineffective at reducing anthraquinoid vat dyes except with gluconic acid. A two ligand system using tartaric acid, triethanolamine or citric acid, triethanolamine complexes iron(II) more stably and effectively reduces and dyes cotton with various vat dyes at room temperature, comparable to sodium hydrosulfite. The stability and dyeing effectiveness depends on maximizing the complexation of iron(II).
Synthesis and Studies of Eco-friendly Acid Dye Metal Complexes and its Applic...IOSR Journals
This document describes the synthesis of eco-friendly acid dye metal complexes and their application on wool fabrics. Specifically, it details the synthesis of substituted pyrazolone metal complex acid dyes from 2-amino-5-bromo benzoic acid that have high yields of 85%. It then discusses dyeing wool fabrics with these complexes and evaluating properties like exhaustion from the dye-bath, fixation of dye on the fabric, color yield, and light and washing fastness. The dye complexes showed excellent color yield and fastness properties. Antibacterial testing also showed activity against both gram-positive and gram-negative bacteria.
Improved Stability of Formate Dehydrogenase by Coating with Didodecyldimethyl...researchinventy
Hydrophilic formate dehydrogenase (FDH) from candida boidinii was chemically modified by coating it with didodecyldimethylammonium bromide (DDAB). This coating changed the phase behavior of the enzyme, making it highly soluble in hydrophobic solvents and thereby offering the chance for biphasic enzyme recycling from hydrophilic substrates and products. Different coating procedures of FDH with DDAB were investigated and all proved suitable for efficient coating of the enzyme’s outer surface. A 50 mM Tris- (hydroxymethyl)-amminomethan (tris) buffer at pH 8 was chosen to make DDAB soluble and avoid aggregation. The reaction of NAD+ with uncoated and coated FDH to NADH and CO2 was monitored by UV-vis spectroscopy and kinetic parameters (rmax, Km, KI , EA) for the the FDH were determined. The coated enzyme resulted in a lower relative initial activity between 40-60% compared to the uncoated one. The stability of the coated enzyme (FDH*) was improved significantly and remained stable in long-term experiments, resulting in a deactivation rate kD smaller than 3% per day and a half-life time t1/2largerthan 23 days, while the deactivation rate of the uncoated enzyme was 260% per daywitha t1/2of 0.3 days. Both activation energies were similar, with 42 kJ mol-1 for the coated and 48 kJ mol-1 for the uncoated enzyme.This result suggests that there is not significant transport resistance originating from the DDAB coating layer. The reason for the significantly lower activity of the coated FDH probably stems from accumulation of formed CO2 in the coating layer, thereby preventing high equilibrium conversions
The photo-oxidation of Rhodamime B was carried out
in the presence of H2O2/ Fe2+ ion using UV light. The effects of
dye concentration, pH, H2O2 dose and Fe2+ dose. These
parameters strongly influenced the degradation of the dye. As
expected, the increase of initial dye concentration decreased the
percentage decoloration. Likewise increasing H2O2, Fe2+
concentration also increased the dye decoloration up to a certain
limit after which it starts decreasing. The optimum operating
conditions of the method were found to be [Dye] = 10mg/l; [H2O2]
= 300mg/l; [Fe2+] = 250 mg/l at pH 2. Under these conditions, a
maximum of 92% decoloration of the dye was achieved. The
actual breakdown of the dye was confirmed using HPLC
analyses.
Potassium permanganate, potassium dichromate – one of the excellent tools of ...Istiqur Rahman
This document discusses pharmaceutical analysis and different types of titration methods. It focuses on redox titration and provides details about common oxidizing agents used - potassium permanganate and potassium dichromate. Potassium permanganate is highlighted as a stronger oxidizing agent compared to potassium dichromate due to its higher oxidation state of +7 and ability to oxidize a wider range of functional groups. Both oxidizing agents are compared in terms of their toxicity, with potassium dichromate noted as being more hazardous to health.
Present study aims to investigate the efficiency of newly synthesized adsorbent polyvinyl
alcohol-alginate bound nano magnetite microspheres modified with cetyltrimethyl ammonium bromide [PVAANM/CTAB]
in removal of anionic dye ‘Alizarin Red S’ from aqueous medium. The effect of agitation time,
influence of pH, amount of adsorbent, initial dye concentration and temperature were systematically studied by
batch sorption system. Various isotherms and kinetic models have been fitted with experimental data to evaluate
mechanism of adsorption. Characterization of the so-prepared adsorbent was accomplished by FTIR, XRD,
SEM and TEM analysis. The experimental data fitted very well with Freundlich and Temkin isotherm model.
The sorption kinetics follows pseudo second order kinetic model. PVA-ANM/CTAB has been found an effective,
economic, eco-friendly and efficient adsorbent as it showed ≥ 98% removal at pH 8 and could be regenerated
by acetic acid and reused.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Synthesis and Studies of Eco-friendly Acid Dye Metal Complexes and its Applic...IOSR Journals
This document describes the synthesis of eco-friendly acid dye metal complexes and their application on wool fabrics. Specifically, it details the synthesis of substituted pyrazolone metal complex acid dyes from 2-amino-5-bromo benzoic acid that have high yields of 85%. It then discusses dyeing wool fabrics with these complexes and evaluating properties like exhaustion from the dye-bath, fixation of dye on the fabric, color yield, and light and washing fastness. The dye complexes showed excellent color yield and fastness properties. Antibacterial testing also showed activity against both gram-positive and gram-negative bacteria.
Improved Stability of Formate Dehydrogenase by Coating with Didodecyldimethyl...researchinventy
Hydrophilic formate dehydrogenase (FDH) from candida boidinii was chemically modified by coating it with didodecyldimethylammonium bromide (DDAB). This coating changed the phase behavior of the enzyme, making it highly soluble in hydrophobic solvents and thereby offering the chance for biphasic enzyme recycling from hydrophilic substrates and products. Different coating procedures of FDH with DDAB were investigated and all proved suitable for efficient coating of the enzyme’s outer surface. A 50 mM Tris- (hydroxymethyl)-amminomethan (tris) buffer at pH 8 was chosen to make DDAB soluble and avoid aggregation. The reaction of NAD+ with uncoated and coated FDH to NADH and CO2 was monitored by UV-vis spectroscopy and kinetic parameters (rmax, Km, KI , EA) for the the FDH were determined. The coated enzyme resulted in a lower relative initial activity between 40-60% compared to the uncoated one. The stability of the coated enzyme (FDH*) was improved significantly and remained stable in long-term experiments, resulting in a deactivation rate kD smaller than 3% per day and a half-life time t1/2largerthan 23 days, while the deactivation rate of the uncoated enzyme was 260% per daywitha t1/2of 0.3 days. Both activation energies were similar, with 42 kJ mol-1 for the coated and 48 kJ mol-1 for the uncoated enzyme.This result suggests that there is not significant transport resistance originating from the DDAB coating layer. The reason for the significantly lower activity of the coated FDH probably stems from accumulation of formed CO2 in the coating layer, thereby preventing high equilibrium conversions
The photo-oxidation of Rhodamime B was carried out
in the presence of H2O2/ Fe2+ ion using UV light. The effects of
dye concentration, pH, H2O2 dose and Fe2+ dose. These
parameters strongly influenced the degradation of the dye. As
expected, the increase of initial dye concentration decreased the
percentage decoloration. Likewise increasing H2O2, Fe2+
concentration also increased the dye decoloration up to a certain
limit after which it starts decreasing. The optimum operating
conditions of the method were found to be [Dye] = 10mg/l; [H2O2]
= 300mg/l; [Fe2+] = 250 mg/l at pH 2. Under these conditions, a
maximum of 92% decoloration of the dye was achieved. The
actual breakdown of the dye was confirmed using HPLC
analyses.
Potassium permanganate, potassium dichromate – one of the excellent tools of ...Istiqur Rahman
This document discusses pharmaceutical analysis and different types of titration methods. It focuses on redox titration and provides details about common oxidizing agents used - potassium permanganate and potassium dichromate. Potassium permanganate is highlighted as a stronger oxidizing agent compared to potassium dichromate due to its higher oxidation state of +7 and ability to oxidize a wider range of functional groups. Both oxidizing agents are compared in terms of their toxicity, with potassium dichromate noted as being more hazardous to health.
Present study aims to investigate the efficiency of newly synthesized adsorbent polyvinyl
alcohol-alginate bound nano magnetite microspheres modified with cetyltrimethyl ammonium bromide [PVAANM/CTAB]
in removal of anionic dye ‘Alizarin Red S’ from aqueous medium. The effect of agitation time,
influence of pH, amount of adsorbent, initial dye concentration and temperature were systematically studied by
batch sorption system. Various isotherms and kinetic models have been fitted with experimental data to evaluate
mechanism of adsorption. Characterization of the so-prepared adsorbent was accomplished by FTIR, XRD,
SEM and TEM analysis. The experimental data fitted very well with Freundlich and Temkin isotherm model.
The sorption kinetics follows pseudo second order kinetic model. PVA-ANM/CTAB has been found an effective,
economic, eco-friendly and efficient adsorbent as it showed ≥ 98% removal at pH 8 and could be regenerated
by acetic acid and reused.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Chelating ion exchange and antimicrobial studiesIJECSJournal
The Copolymer (p-HBTF-I) was synthesized by condensation of p-hydroxybenzoicacid and thiosemicarbazide with formaldehyde in the presence of 2M HCL as a catalyst at 126 ± 2 0C for 5 hrs. with molar proportion of reactants. The copolymer (p-HBTF-I) was characterized by elemental analysis, FT-IR, UV-Visible 1H-NMR Spectroscopy. The chelating ion-exchange property of this polymer was studied for five metal ions viz. Cu (II), Ni (II), Co (II), Zn (II), and Pb (II) ions. The chelating ion-exchange study was carried out over a wide range of pH, shaking time and in mediaof various ionic strengths. The copolymer possesses antimicrobial activity for certain bacteria such as B. Subtilis, ,E.Coli, S. Typhi .
Eco friendly dyeing of viscose fabric with reactive dyesiaemedu
This document summarizes research on eco-friendly dyeing of viscose fabric with reactive dyes using polyacrylic acid and cross-linking agents. The researcher synthesized and characterized polyacrylic acid and the cross-linking agent glycerol-1,3-dichlorohydrin. Viscose fabric was treated with optimized concentrations of polyacrylic acid and a cross-linking agent, then dyed with various reactive dyes without salt or alkali at neutral pH. Different dyeing processes were tested and dye uptake was evaluated. The treated fabric showed improved dyeability with reactive dyes at neutral pH without conventional chemicals.
Eco friendly dyeing of viscose fabric with reactive dyesiaemedu
This document summarizes a study on eco-friendly dyeing of viscose fabric with reactive dyes. The study synthesized and characterized polyacrylic acid and a cross-linking agent called glycerol-1,3-dichlorohydrin. Viscose fabric was pretreated with polyacrylic acid and the cross-linking agent and then dyed with various reactive dyes without using salt, alkali or other chemicals in the dyebath. The dyed fabrics were evaluated for color strength and fastness properties and compared to conventionally dyed samples. The goal was to develop a non-polluting reactive dyeing process for cellulosic fabrics like viscose.
Synthesis, Structure Investigation and Dyeing Assessment of Novel Bisazo Disp...IOSR Journals
Novel bisazo-disperse dyes were prepared by the coupling of diazotized solutions of various aromatic diamines with 2,4-dihydroxybenzophenone. The resultant bisazo disperse dyes were characterized by elemental analysis, IR and 1H NMR spectral studies. The UV Visible absorption spectral data were investigated in dimethylformamide. and are discussed in terms of structural property relationship. Their dyeing assessment of bisazo disperse dyes has been made on polyester fabrics. The results show that a better hue was obtained on polyester fabrics and have mild to moderate fastness properties.
This document summarizes a study on the adsorption of a Schiff base ligand onto granulated initiated calcined Iraqi montmorillonite clay via columnar method. The ligand was synthesized from the condensation reaction of hydrazine hydrate and 4-hydroxy-3-methoxybenzaldehyde. Adsorption experiments were conducted in columns packed with the clay at different pH levels, ligand concentrations, and contact times. The equilibrium adsorption data fit the Langmuir, Freundlich and Temkin isotherm models. The maximum adsorption capacity was found to be 5.7347 mg ligand per 1g clay. The highest removal rate of 75.7% occurred at pH 7. Kinetic data followed pseudo
Twelve dyes were synthesized by diazotizing six primary aromatic amines, which were subsequently coupled with H-acid(1-napthol-8-amino-3,6-disulphonic acid).Each of these amines wasalso diazotized and coupled with abenzoylated H-acid.The colours obtained were mainly pink, red and orange. The various dyes synthesized were applied onto a Nylon 6.6. The molecular weights of the dyes, as well as their molar extinction coefficients were calculated and their solubility in water was determined. Their maximum absorption wavelength was measured in water. The fastness properties of the dyes were also investigated. They had good fastness properties. Benzoylated acid dyes give brighter shades and high wet fastness properties on nylon 6.6, due to their high molecular weight. They also have good exhaustion properties.
Evaluation of titanium in hydrochloric acid solutions containing corrosion in...IOSR Journals
This document evaluates the corrosion of titanium in hydrochloric acid solutions containing various corrosion inhibitors. Laboratory tests were conducted on titanium coupons immersed in 10% hydrochloric acid at 50°C and 70°C with additions of phenylamine, thiocarbamide, β-naphthol, and a mixture of thiocarbamide and β-naphthol. The results showed that thiocarbamide provided the best corrosion protection, reducing the corrosion rate by 50-80% depending on concentration and temperature. Higher temperatures and concentrations increased corrosion, showing the need for effective corrosion inhibitors when using hydrochloric acid in oil and gas operations.
The document summarizes research on the indirect electrochemical reduction of vat dyes using an iron-triethanolamine complex mediator system. Vat dyes are typically reduced using sodium dithionite, but this produces harmful byproducts. The study explores using electrochemistry and an iron-TEA mediator to reduce vat dyes in an environmentally friendly manner. Experiments are conducted to determine dye reduction potentials and optimize iron-TEA-NaOH ratios for dyeing cotton. Color yields are compared between the new electrochemical method and conventional sodium dithionite reduction.
This document discusses types and sources of impurities in active pharmaceutical ingredients (APIs). It outlines various types of impurities including organic, inorganic, residual solvents, and genotoxic impurities. Synthesis and formulation related impurities are described that can arise from starting materials, degradation, byproducts, excipients, and processing methods. Special attention is given to genotoxic impurities which are potentially mutagenic and carcinogenic even in low concentrations. Examples are provided of compounds used in synthesis like alkyl halides and epoxides that can lead to genotoxic impurities.
This document summarizes a study on dispersing reduced graphene in organic solvents through noncovalent functionalization with end-functional polymers. The researchers prepared an aqueous dispersion of reduced graphene oxide through chemical reduction, then tested its dispersibility in various organic solvents. To disperse the graphene in nonsolvents, they noncovalently functionalized it with amine-terminated polymers via sonication. FTIR and Raman spectroscopy confirmed the amine groups on the polymers interacted with carboxyl groups on the graphene surface, enhancing dispersibility in organic media.
Synthesis and characterization of antioxidant resin modified Alexander Decker
This document summarizes the synthesis and characterization of antioxidant resins modified from bisphenol A and formaldehyde. Bisphenol A was condensed with formaldehyde to form a methylolic resin (Resin I) which was then converted to alkoxy derivatives (Resins II, III, IV). The resins were characterized using techniques like IR spectroscopy, NMR, elemental analysis and thermogravimetric analysis. The resins showed good thermal stability and low volatility. When added to lubricating oil at concentrations up to 0.5%, Resins II, III and IV significantly improved the oxidation stability of the oil as measured by reduced acidity, carbonyl index and viscosity change over 12 hours of oxidation testing compared to oil
Spectroscopic and Colorimetric Determination of Meloxicam, Lornoxicam, Tenoxi...BRNSS Publication Hub
New approach to spectrophotometric and colorimetric determination of meloxicam, lornoxicam, tenoxicam in drugs using 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD chloride) is developed. The techniques are based on alkaline hydrolyses of oxicams with NBD chloride and the subsequent spectrophotometric and colorimetric determination of the colored products of reaction. The linearity range of calibration dependence is 1-10 mg/ml for lornoxicam and tenoxicam, 0.5-5 mg/ml for meloxicam. The advantages of developed methods are rapidity and cost-efficiency. This approach can be used for screening control of drug quality.
No 14. plant physiology and fruit secondary metabolites of canistel (pouteria...PARTNER, BADC, World Bank
The document summarizes a study on the plant physiology and secondary metabolites of canistel (Pouteria campechiana) fruits. Several plant physiological parameters were measured including leaf area, chlorophyll content, photosynthetic rate, stomatal conductance, CO2 references, H2O references, and light intensity on leaves. Fruit characteristics like size, weight, yield, brix, moisture, and vitamin C content were also determined. Qualitative tests were performed to screen the hydro-alcoholic, methanol, and aqueous extracts of canistel fruits for various secondary metabolites. Alkaloids, glycosides, carbohydrates, tannins, terpenoids, steroids, reducing sugars, proteins,
Reactive dye (B.Sc in Textile Engineering)Mazharul Islam
This document provides information about reactive dyes used for dyeing cotton fabrics. It discusses the general structure and properties of reactive dyes, including that they form covalent bonds with fibers. The document also summarizes the dyeing process, which involves dye exhaustion, fixation in an alkaline environment, and washing off unfixed dye. Factors that affect dye hydrolysis are outlined, such as liquor ratio, salt concentration, and temperature. The role of salt and alkali in the dyeing process is also explained.
Sugar fermentation tests, Cetrimide agar medium, Hugh Leifson medium Shivam kumar Sriwas
1. The document discusses sugar fermentation, how to test for it using media like phenol red carbohydrate broth, and the interpretation of results.
2. Hugh Leifson medium and Cetrimide agar are described as media used to differentiate bacterial metabolism and isolate Pseudomonas aeruginosa, respectively.
3. Key components, principles, preparation, and expected results are outlined for both Hugh Leifson medium and Cetrimide agar tests.
Lecture 2 composition of cotton, desizingAdane Nega
The document discusses the composition and constituents of cotton fibers, including natural impurities, fats and waxes, pectins, proteins, colouring matter, and mineral matter. It also describes sizing agents that are added during weaving to improve productivity. The main methods for removing sizing agents and other impurities from cotton fibers are hydrolytic desizing using acid or enzymes, as well as oxidative desizing. Enzyme desizing using bacterial enzymes is commonly used in the textile industry today.
The document discusses salt-free dyeing of cotton with reactive dyes. It examines pretreating cotton with cationic agents via exhaust and pad-dry methods, and then dyeing without salt. Experiments compare exhaustion and fixation of representative reactive dyes on cotton pretreated with cationic agents and dyed with or without salt. The objectives are to study the effect of cationic agents on wash/light fastness and dye-fiber bonding, and suggest a mechanism for reactive dye exhaustion without salt using cationic agents. Methods involve pretreatment with various cationic agents, dyeing representative dyes, and analyzing exhaustion, color yield, and fastness properties. Results show cationic agents can increase exhaustion and color yield compared to dye
This document discusses major environmental issues related to the chemical processing of textiles in India, particularly regarding water usage and pollution. It notes that India is approaching a state of water stress and textile processing is a major consumer and polluter of water resources. The document examines in detail the case of the textile industry cluster in Tirupur, Tamil Nadu, which has depleted local groundwater sources and contaminated surface water through untreated effluent discharge. It emphasizes the need to reduce fresh water usage through wastewater recycling and cleaner production technologies in the textile industry.
This article discusses indirect electrochemical reduction of vat dyes using an iron-triethanolamine complex as a reducing agent. It describes the application and mechanism of indirect electrolysis for dye reduction. Dyeing experiments are conducted under different reduction conditions and the results are compared to a standard sodium dithionite method in terms of color depth, shade, and fastness properties. The new process offers environmental benefits and improved process stability through monitoring of reduction potential in the dye bath.
The document discusses the bleaching of cotton fabric using chlorine-based bleaching agents such as bleaching powder and sodium hypochlorite. It explains that the objective of bleaching is to produce a white fabric by destroying color compounds while minimizing fiber degradation. It then describes the manufacturing process for bleaching powder and sodium hypochlorite, and compares their properties and effects on bleaching cotton at different pH levels, temperatures, and concentrations. Finally, it outlines the typical industrial bleaching operation process.
Digital printing asian dyer extended version)Adane Nega
Digital printing offers several advantages over conventional analog printing methods for textiles. It allows for mass customization and quick turnaround due to minimal press setup times. Digital printing can change color schemes or designs in real time during production. It also produces less waste and has a lower environmental impact than screen printing. However, digital printing has lower throughput than analog methods and higher costs for long runs. It also requires specially coated substrates and has limitations in ink color options and opacity.
Chelating ion exchange and antimicrobial studiesIJECSJournal
The Copolymer (p-HBTF-I) was synthesized by condensation of p-hydroxybenzoicacid and thiosemicarbazide with formaldehyde in the presence of 2M HCL as a catalyst at 126 ± 2 0C for 5 hrs. with molar proportion of reactants. The copolymer (p-HBTF-I) was characterized by elemental analysis, FT-IR, UV-Visible 1H-NMR Spectroscopy. The chelating ion-exchange property of this polymer was studied for five metal ions viz. Cu (II), Ni (II), Co (II), Zn (II), and Pb (II) ions. The chelating ion-exchange study was carried out over a wide range of pH, shaking time and in mediaof various ionic strengths. The copolymer possesses antimicrobial activity for certain bacteria such as B. Subtilis, ,E.Coli, S. Typhi .
Eco friendly dyeing of viscose fabric with reactive dyesiaemedu
This document summarizes research on eco-friendly dyeing of viscose fabric with reactive dyes using polyacrylic acid and cross-linking agents. The researcher synthesized and characterized polyacrylic acid and the cross-linking agent glycerol-1,3-dichlorohydrin. Viscose fabric was treated with optimized concentrations of polyacrylic acid and a cross-linking agent, then dyed with various reactive dyes without salt or alkali at neutral pH. Different dyeing processes were tested and dye uptake was evaluated. The treated fabric showed improved dyeability with reactive dyes at neutral pH without conventional chemicals.
Eco friendly dyeing of viscose fabric with reactive dyesiaemedu
This document summarizes a study on eco-friendly dyeing of viscose fabric with reactive dyes. The study synthesized and characterized polyacrylic acid and a cross-linking agent called glycerol-1,3-dichlorohydrin. Viscose fabric was pretreated with polyacrylic acid and the cross-linking agent and then dyed with various reactive dyes without using salt, alkali or other chemicals in the dyebath. The dyed fabrics were evaluated for color strength and fastness properties and compared to conventionally dyed samples. The goal was to develop a non-polluting reactive dyeing process for cellulosic fabrics like viscose.
Synthesis, Structure Investigation and Dyeing Assessment of Novel Bisazo Disp...IOSR Journals
Novel bisazo-disperse dyes were prepared by the coupling of diazotized solutions of various aromatic diamines with 2,4-dihydroxybenzophenone. The resultant bisazo disperse dyes were characterized by elemental analysis, IR and 1H NMR spectral studies. The UV Visible absorption spectral data were investigated in dimethylformamide. and are discussed in terms of structural property relationship. Their dyeing assessment of bisazo disperse dyes has been made on polyester fabrics. The results show that a better hue was obtained on polyester fabrics and have mild to moderate fastness properties.
This document summarizes a study on the adsorption of a Schiff base ligand onto granulated initiated calcined Iraqi montmorillonite clay via columnar method. The ligand was synthesized from the condensation reaction of hydrazine hydrate and 4-hydroxy-3-methoxybenzaldehyde. Adsorption experiments were conducted in columns packed with the clay at different pH levels, ligand concentrations, and contact times. The equilibrium adsorption data fit the Langmuir, Freundlich and Temkin isotherm models. The maximum adsorption capacity was found to be 5.7347 mg ligand per 1g clay. The highest removal rate of 75.7% occurred at pH 7. Kinetic data followed pseudo
Twelve dyes were synthesized by diazotizing six primary aromatic amines, which were subsequently coupled with H-acid(1-napthol-8-amino-3,6-disulphonic acid).Each of these amines wasalso diazotized and coupled with abenzoylated H-acid.The colours obtained were mainly pink, red and orange. The various dyes synthesized were applied onto a Nylon 6.6. The molecular weights of the dyes, as well as their molar extinction coefficients were calculated and their solubility in water was determined. Their maximum absorption wavelength was measured in water. The fastness properties of the dyes were also investigated. They had good fastness properties. Benzoylated acid dyes give brighter shades and high wet fastness properties on nylon 6.6, due to their high molecular weight. They also have good exhaustion properties.
Evaluation of titanium in hydrochloric acid solutions containing corrosion in...IOSR Journals
This document evaluates the corrosion of titanium in hydrochloric acid solutions containing various corrosion inhibitors. Laboratory tests were conducted on titanium coupons immersed in 10% hydrochloric acid at 50°C and 70°C with additions of phenylamine, thiocarbamide, β-naphthol, and a mixture of thiocarbamide and β-naphthol. The results showed that thiocarbamide provided the best corrosion protection, reducing the corrosion rate by 50-80% depending on concentration and temperature. Higher temperatures and concentrations increased corrosion, showing the need for effective corrosion inhibitors when using hydrochloric acid in oil and gas operations.
The document summarizes research on the indirect electrochemical reduction of vat dyes using an iron-triethanolamine complex mediator system. Vat dyes are typically reduced using sodium dithionite, but this produces harmful byproducts. The study explores using electrochemistry and an iron-TEA mediator to reduce vat dyes in an environmentally friendly manner. Experiments are conducted to determine dye reduction potentials and optimize iron-TEA-NaOH ratios for dyeing cotton. Color yields are compared between the new electrochemical method and conventional sodium dithionite reduction.
This document discusses types and sources of impurities in active pharmaceutical ingredients (APIs). It outlines various types of impurities including organic, inorganic, residual solvents, and genotoxic impurities. Synthesis and formulation related impurities are described that can arise from starting materials, degradation, byproducts, excipients, and processing methods. Special attention is given to genotoxic impurities which are potentially mutagenic and carcinogenic even in low concentrations. Examples are provided of compounds used in synthesis like alkyl halides and epoxides that can lead to genotoxic impurities.
This document summarizes a study on dispersing reduced graphene in organic solvents through noncovalent functionalization with end-functional polymers. The researchers prepared an aqueous dispersion of reduced graphene oxide through chemical reduction, then tested its dispersibility in various organic solvents. To disperse the graphene in nonsolvents, they noncovalently functionalized it with amine-terminated polymers via sonication. FTIR and Raman spectroscopy confirmed the amine groups on the polymers interacted with carboxyl groups on the graphene surface, enhancing dispersibility in organic media.
Synthesis and characterization of antioxidant resin modified Alexander Decker
This document summarizes the synthesis and characterization of antioxidant resins modified from bisphenol A and formaldehyde. Bisphenol A was condensed with formaldehyde to form a methylolic resin (Resin I) which was then converted to alkoxy derivatives (Resins II, III, IV). The resins were characterized using techniques like IR spectroscopy, NMR, elemental analysis and thermogravimetric analysis. The resins showed good thermal stability and low volatility. When added to lubricating oil at concentrations up to 0.5%, Resins II, III and IV significantly improved the oxidation stability of the oil as measured by reduced acidity, carbonyl index and viscosity change over 12 hours of oxidation testing compared to oil
Spectroscopic and Colorimetric Determination of Meloxicam, Lornoxicam, Tenoxi...BRNSS Publication Hub
New approach to spectrophotometric and colorimetric determination of meloxicam, lornoxicam, tenoxicam in drugs using 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD chloride) is developed. The techniques are based on alkaline hydrolyses of oxicams with NBD chloride and the subsequent spectrophotometric and colorimetric determination of the colored products of reaction. The linearity range of calibration dependence is 1-10 mg/ml for lornoxicam and tenoxicam, 0.5-5 mg/ml for meloxicam. The advantages of developed methods are rapidity and cost-efficiency. This approach can be used for screening control of drug quality.
No 14. plant physiology and fruit secondary metabolites of canistel (pouteria...PARTNER, BADC, World Bank
The document summarizes a study on the plant physiology and secondary metabolites of canistel (Pouteria campechiana) fruits. Several plant physiological parameters were measured including leaf area, chlorophyll content, photosynthetic rate, stomatal conductance, CO2 references, H2O references, and light intensity on leaves. Fruit characteristics like size, weight, yield, brix, moisture, and vitamin C content were also determined. Qualitative tests were performed to screen the hydro-alcoholic, methanol, and aqueous extracts of canistel fruits for various secondary metabolites. Alkaloids, glycosides, carbohydrates, tannins, terpenoids, steroids, reducing sugars, proteins,
Reactive dye (B.Sc in Textile Engineering)Mazharul Islam
This document provides information about reactive dyes used for dyeing cotton fabrics. It discusses the general structure and properties of reactive dyes, including that they form covalent bonds with fibers. The document also summarizes the dyeing process, which involves dye exhaustion, fixation in an alkaline environment, and washing off unfixed dye. Factors that affect dye hydrolysis are outlined, such as liquor ratio, salt concentration, and temperature. The role of salt and alkali in the dyeing process is also explained.
Sugar fermentation tests, Cetrimide agar medium, Hugh Leifson medium Shivam kumar Sriwas
1. The document discusses sugar fermentation, how to test for it using media like phenol red carbohydrate broth, and the interpretation of results.
2. Hugh Leifson medium and Cetrimide agar are described as media used to differentiate bacterial metabolism and isolate Pseudomonas aeruginosa, respectively.
3. Key components, principles, preparation, and expected results are outlined for both Hugh Leifson medium and Cetrimide agar tests.
Lecture 2 composition of cotton, desizingAdane Nega
The document discusses the composition and constituents of cotton fibers, including natural impurities, fats and waxes, pectins, proteins, colouring matter, and mineral matter. It also describes sizing agents that are added during weaving to improve productivity. The main methods for removing sizing agents and other impurities from cotton fibers are hydrolytic desizing using acid or enzymes, as well as oxidative desizing. Enzyme desizing using bacterial enzymes is commonly used in the textile industry today.
The document discusses salt-free dyeing of cotton with reactive dyes. It examines pretreating cotton with cationic agents via exhaust and pad-dry methods, and then dyeing without salt. Experiments compare exhaustion and fixation of representative reactive dyes on cotton pretreated with cationic agents and dyed with or without salt. The objectives are to study the effect of cationic agents on wash/light fastness and dye-fiber bonding, and suggest a mechanism for reactive dye exhaustion without salt using cationic agents. Methods involve pretreatment with various cationic agents, dyeing representative dyes, and analyzing exhaustion, color yield, and fastness properties. Results show cationic agents can increase exhaustion and color yield compared to dye
This document discusses major environmental issues related to the chemical processing of textiles in India, particularly regarding water usage and pollution. It notes that India is approaching a state of water stress and textile processing is a major consumer and polluter of water resources. The document examines in detail the case of the textile industry cluster in Tirupur, Tamil Nadu, which has depleted local groundwater sources and contaminated surface water through untreated effluent discharge. It emphasizes the need to reduce fresh water usage through wastewater recycling and cleaner production technologies in the textile industry.
This article discusses indirect electrochemical reduction of vat dyes using an iron-triethanolamine complex as a reducing agent. It describes the application and mechanism of indirect electrolysis for dye reduction. Dyeing experiments are conducted under different reduction conditions and the results are compared to a standard sodium dithionite method in terms of color depth, shade, and fastness properties. The new process offers environmental benefits and improved process stability through monitoring of reduction potential in the dye bath.
The document discusses the bleaching of cotton fabric using chlorine-based bleaching agents such as bleaching powder and sodium hypochlorite. It explains that the objective of bleaching is to produce a white fabric by destroying color compounds while minimizing fiber degradation. It then describes the manufacturing process for bleaching powder and sodium hypochlorite, and compares their properties and effects on bleaching cotton at different pH levels, temperatures, and concentrations. Finally, it outlines the typical industrial bleaching operation process.
Digital printing asian dyer extended version)Adane Nega
Digital printing offers several advantages over conventional analog printing methods for textiles. It allows for mass customization and quick turnaround due to minimal press setup times. Digital printing can change color schemes or designs in real time during production. It also produces less waste and has a lower environmental impact than screen printing. However, digital printing has lower throughput than analog methods and higher costs for long runs. It also requires specially coated substrates and has limitations in ink color options and opacity.
The textile industry in India faces significant challenges from technological obsolescence and environmental problems. Many textile mills still use outdated machinery and processes that are decades old, resulting in low production efficiency and capacity utilization. This technological obsolescence has contributed to India's small 3% share of the global textile market compared to China's goal of 40%. The textile industry also generates substantial air, water, soil and noise pollution from untreated effluents and emissions. Addressing these issues through modernization efforts and investments in new technologies is critical for the industry to become more competitive and sustainable.
This document discusses various methods for water conservation in textile processing, which can reduce effluent volume and treatment costs. Key methods mentioned include improving housekeeping to fix leaks, installing water meters, reusing cooling and washing water through countercurrent flow systems, and optimizing chemical usage. Case studies show that these measures have successfully reduced fresh water consumption by up to 40% and lowered biochemical oxygen demand in effluent.
The document summarizes the general composition and essential qualities of print pastes used in textile printing. Print pastes typically contain dyestuffs, thickeners, solvents, humectants, oxidizing agents, and defoaming agents. Thickeners are important for ensuring the print paste sinks into the fabric quickly and adheres properly after printing and drying. Other components like hydroscopic agents and pH controllers help facilitate dye fixation during steam treatment. Proper selection and balance of ingredients is necessary for achieving high quality, well-defined prints on fabrics.
The document summarizes the MGIRI Solar Charkha, a technology developed to operate charkhas (spinning wheels) using solar power as an alternative to manual operation. Some key points:
- The solar-powered charkha system uses a solar panel, controller, battery and motor to run the charkha at a constant speed, increasing productivity over manual operation.
- It eliminates the drudgery of manual spinning while allowing one operator to oversee multiple charkhas. Production and wages are increased.
- Solar energy provides a solution to power charkhas in rural areas lacking electricity access. The technology could also provide lighting and fans.
- Adopting this technology could
Lecture 2 composition of cotton, desizingAdane Nega
The document discusses the composition and constituents of cotton, including natural impurities, fats and waxes, pectins, proteins, colouring matter, and mineral matter. It also discusses added impurities from sizing agents used in weaving. The purpose of preparatory processes is to remove impurities from cotton to impart desirable properties. Desizing is the process of removing size, which facilitates further processing by making starch water soluble through hydrolysis, oxidation, or enzymatic reactions. Common desizing methods include acid desizing, enzyme desizing, and oxidative desizing.
The document discusses the history and process of mercerization of cotton. It describes how John Mercer discovered in 1791 that treating cotton with a sodium hydroxide solution caused it to shrink. In the 1850s, Mercer patented the mercerization process. Later improvements by Horace Lowe and Thomas and Prevost reduced shrinkage by applying tension during treatment. The process was then commercialized in 1895 and is now widely used to increase cotton's strength, dye absorption, and other properties.
Roller printing was invented by James Bell of Scotland in 1783. It was the first machine used for textile printing and remained popular for over 200 years until the 1960s. The roller printing machine used engraved rollers to transfer designs onto fabric passing between multiple rollers. It could print 1 to 12 colors at speeds of 70-80 meters per minute. The popularity of roller printing declined after the invention of rotary screen printing in 1960, which allowed for faster, multi-color printing and is now obsolete.
Lecture 2 composition of cotton, desizingAdane Nega
The document discusses the composition and constituents of cotton fibers, including natural impurities, fats and waxes, pectins, proteins, colouring matter, and mineral matter. It also describes the purpose and principles of preparatory processes used in the textile industry such as desizing. Desizing is the process of removing size, primarily starch, applied during weaving to prevent warp breakage. Common desizing methods include hydrolysis using acids or enzymes to break down starch into soluble fragments.
Tarpaulins are thick fabric sheets made from materials like cotton, polyester, nylon, PVC, PE or PP. They are used in various industrial applications as protective covers. Common applications include uses in agriculture, construction, sports, defense and more. Tarpaulins are finished and coated to make them water resistant, fire resistant, UV protected and durable for outdoor use. Popular types include cotton/polyester blends and polyester films laminated with PE or PP.
Organic cotton is more environmentally friendly than conventional cotton. Conventional cotton requires heavy use of fertilizers and pesticides that pollute water and soil and pose health risks. Organic cotton is cultivated without these chemicals. It takes three years after switching to organic methods for the cotton to be certified organic and free of chemical residues. Farmers in India organize to produce organic cotton through associations like the Vidarbha Organic Farmers Association in order to have a cleaner, safer approach to cotton cultivation.
The document discusses various waste minimization techniques used in the textile industry, including process optimizations, chemical substitutions, and effluent treatment. Specific examples include replacing starch with PVA in sizing, using low-salt reactive dyes, lowering liquor ratios in dyeing, and treating effluent with screening, equalization, coagulation, sedimentation, and activated sludge processes. A case study describes measures taken at a textile mill in India that reduced total effluent volume by 25,000 liters per day and pollution load by 40-45% through various waste reduction efforts.
The document defines dyeing as uniformly coloring textile materials like fibers, yarns or fabrics. Dyes are soluble color compounds that penetrate the fiber cross-section and interact with fibers through affinity, while pigments are insoluble and have no affinity. Dye-fiber interaction depends on factors like the nature of the dye and fiber. Dyes are classified based on their solubility and suitability for different fibers like cotton, wool, nylon etc. Dyeing involves introducing fiber into a dye bath containing dye, water and auxiliaries, and is influenced by dye exhaustion and affinity between dye and fiber.
Correlation between thermodynamic parameters andAlexander Decker
Nine carboxylated reactive dyes were synthesized and applied to silk fabric. The dyes showed high equilibrium exhaustion percentages between 80-97% on the silk. However, wash fastness was poor due to weak dye-fiber bonds. Aftertreatment with carbodiimide improved fixation and significantly increased wash fastness for dyes containing carboxylic acid groups by forming covalent bonds between the dye and silk fiber. Thermodynamic parameters like partition coefficient and standard affinity correlated with exhaustion percentage and were higher for dyes with stronger dye-fiber interactions.
Redox Mediated Decolorization and Detoxification of Direct Blue 80 by Partial...Agriculture Journal IJOEAR
Abstract— Textile industries are releasing a large number of toxic synthetic dyes into waste waters. Hence, the removal of such compounds from environment prior to their final disposal is necessary. In the present study, potential use of ginger (Zingiber officinale) peroxidase in decolorization and detoxification of direct blue 80 has been investigated. It was found that only 0.166 U/ml of ginger peroxidase was sufficient for maximum decolorization of dye (25 mg/L). H2O2 was required in low concentration (0.3 mM) in the presence of 0.6 mM 1-hydroxybenzotriazole. Direct blue 80 was also successfully removed in stirred batch process. It was observed that ginger peroxidase was highly stable over a wide range of pH and temperatures. Km and Vmax of the enzyme for direct blue 80 was found to be 27.8 mg/L and 2.09 mg/L/min, respectively. In UV-visible spectral analysis a sharp decline in peak was observed for the treated direct blue 80 which substantiates the breakdown of chromophore group of dye. Genotoxicity assessment by comet assay and chromosomal aberration test confirmed that the direct blue 80 was successfully detoxified by ginger peroxidase. Other direct and acid dyes were also treated either as a single or a mixture of different dyes and it was observed that these dyes were also decolorized significantly under similar experimental conditions. Our study suggests that this enzyme-redox mediator system constitutes a cost effective model which can decolorize the industrial textile effluents and also can reduce the toxic load of environment.
This document provides information on reactive dyes, including:
1. Reactive dyes form covalent bonds with cellulose fibers through chemical reactions in alkaline conditions.
2. They are classified based on functional groups and reactivity levels.
3. The three-step dyeing process involves initial absorption, alkali fixation, and post-dyeing washing.
1) New green chemical techniques are being developed for textile coloration processes to reduce environmental impacts. This includes using natural dyes, more sustainable dye syntheses, and processes that decrease water and energy usage.
2) The document discusses developing a more hydrophobic derivative of the natural dye alizarin called 1H2EA to dye polyesters like PET. 1H2EA provides brighter colors with less sensitivity to pH compared to alizarin.
3) Alternative reducing agents for sulphur dyeing are explored to replace sulfides which can damage wastewater systems. Sugars and electrolysis methods show promise but require more research to optimize color strength and fastness.
The document discusses several limit tests used to check for impurities in samples according to the Indian Pharmacopoeia, including tests for chloride, sulphate, iron, arsenic, heavy metals, and lead. The limit tests involve comparing the visible reaction of the sample to a standard solution to determine if the level of impurity exceeds the limit. The reactions form precipitates or complexes that can be observed and compared between the sample and standard.
Effect of hardness of water on fixation and total wash off percentage of reac...Elias Khalil (ইলিয়াস খলিল)
Dye-house water quality is the most important parameter to be confirmed before dyeing; precisely the presence of metal content i.e. Hardness. This research will investigate & analyses the impact of separate hardness (i.e. Calcium, Magnesium & Iron) on particular „Turquoise‟ (C.I. Reactive Blue 21) & a „High Exhaustion‟ class (C.I. HE Red 120, C.I. HE Yellow 84) of Reactive dye on cotton knitted-fabric. From evaluation of dyed fabric the range of metal content is sorted out where the quality starts to fluctuate as distinctive visible & spectral change of shade & fixation rate of the dye molecules has been found. The result of the work will help for further projection about water quality degradation in upcoming years & its effect on dyeing behavior, also the sustainability of present dyeing process to cope with the ever degrading quality of water.
This document summarizes a study on using biodegradable organic salts as alternatives to inorganic salts and alkalis in the reactive dyeing of cotton textiles. The study found that three biodegradable polycarboxylic sodium salts - sodium edate, trisodium NTA, and tetrasodium GLDA - can provide color yields and fastness properties comparable to traditional inorganic salts and alkalis when used in pad-steam dyeing. Tetrasodium GLDA particularly increased color yield for one reactive dye. Using the organic salts also reduced the total dissolved solids in the dyeing effluent, offering environmental benefits over conventional reactive dyeing methods.
The document summarizes the bleaching process of cotton fabric. It discusses how cotton becomes discolored from pigments and processing. The main types of bleaching are chemical and physical. Chemical bleaching uses oxidizing agents like hydrogen peroxide, sodium hypochlorite, and sodium chlorite to break down coloring matters. Physical bleaching increases brightness using optical brighteners without chemical breakdown. Factors like pH, temperature, and concentrations affect the bleaching efficiency and fiber damage. Tests for degree of whiteness and fluidity help evaluate bleaching performance.
Synthesis and Application of Azo Disperse Reactive Dyes derived from p-Aminob...IJERA Editor
Disperse reactive dyes were synthesized by diazotizing p-aminobenzaldehyde and coupling with different substituted pyridones and 2-naphthol. The dyeing performance of the dyes was assessed on polyester, nylon, cotton and wool fabrics. The dyes obtained gave various shades of yellow with good depth, brightness and leveling properties on the fabrics. The dyed fabric showed fairly good to very good light fastness and very good to excellent fastness to washing, hot pressing and rubbing. The dyebath exhaustion on the polyester, nylon, wool and cotton fabrics was found to be very good and fixation on wool was better than on cotton fabric.
Dyeing involves using dyes that have an affinity for fibers. Dyes are soluble colored compounds that can penetrate fibers and form bonds with them. The type of bond formed depends on the fiber and dye, and stronger bonds lead to better fastness. There are several types of dyes like direct dyes, reactive dyes, vat dyes, acid dyes, metal complex dyes, and basic dyes that differ in their properties and how they interact with fibers. Key factors that affect dyeing include dye properties, fiber properties, temperature, time, liquor ratio, and process used.
Dyeing of cellulosic and modified fiber with vat dyegezuketema2009
Vat dyes are insoluble in water but can be converted to a water-soluble leuco form through chemical reduction. This leuco form penetrates cellulosic fibers and is then reoxidized inside the fiber. Vat dyes have good fastness properties and are often used for fabrics subjected to washing and bleaching. The document discusses the characteristics, classification, application mechanisms, and processes of vat dyeing including reduction, absorption into fibers, oxidation, and soaping. It also covers issues like over-reduction and methods of improving levelness and penetration.
Use of titanium dioxide photocatalysis on the remediationBruno B Garcia
This study investigated the photocatalytic degradation of two azo dyes found in textile wastewater using titanium dioxide (TiO2) photocatalysis. The effects of TiO2 concentration, UV irradiation time, solution pH, initial dye concentration, and hydrogen peroxide concentration on degradation were examined. Optimal conditions for highest degradation rates were determined. Results showed that complete decolorization of solutions could be achieved using an efficient photocatalyst under suitable operational parameters.
Introduction of vat dye /Some knowledge for Vat dyes.TonmoyMollick
The document discusses vat dyes, which are water-insoluble dyes that must be chemically modified before use. It provides details on:
- The history and development of vat dyes, with the original being indigo obtained from plants.
- The chemical process of reducing vat dyes with sodium dithionite to create water-soluble leuco compounds that can be applied to fabrics.
- The dyeing process, which involves vatting, dyeing the fabric in alkaline conditions, oxidizing the dye, and soaping to improve fastness.
- Examples of common vat dyes like indanthrones and flavanthrones and their properties.
- The excellent fastness to light
Synthesis, Characterization and Dyeing Performance of Novel Bisazo Bisazometh...ijtsrd
Azo dyes and pigment forms the largest group of all the synthetic colorants and play a prominent role in almost every type of applications. In the last couple of decades a number of major changes have occurred primarily aimed at minimizing the major weakness of anthraquinone dyes. For this purpose attempts were made to replace anthraquinone dyes by azo dyes. For this purpose we have undertaken the work in this direction with a view to synthesize novel bisazo bisazomethine disperse dyes. Therefore, it is worthwhile to describe the chemistry and development of azo and bisazo dyes in brief for the sake of better understanding. Bisazo and bisazomethine dyes are of current important, however there are very few reports regarding bisazo bisazomethine disperse dye. In the textile industry, different fibers used for dyeing are all natural fiber like cellulose linen, cotton or animal protein fibers wool, silk, animal hair and synthetic fibers like nylon, polyester, polyacrylonitrile and blends of two or more fibers. The development of a new substrate presents new dyes and dyeing methods and it influence dyeing technology in a fundamental manner. New bisazo bisazomethine disperse dyes were prepared by the coupling of diazotized solutions of various aromatic primary amines with 2, 2’ {1,4 phenylenebis nitrilomethylylidene } diphenol Schiff base . Schiff base was prepared by the condensation of 2 hydroxybenzaldehyde with 4 aminoaniline. The resultant dyes were characterized by elemental analysis, IR and 1H NMR Spectral Studies. The UV visible absorption spectral data were investigated in dimethylformamide DMF and are discussed in terms of structure property relationship. The dyes when applied on polyester fabric, gave pale yellow to orange shades having fairly good to good light fastness, very good to excellent washing, perspiration and sublimation fastness and good to very good rubbing fastness properties. D M Patel | Rakshit G Patel "Synthesis, Characterization and Dyeing Performance of Novel Bisazo-Bisazomethine Disperse Dyes on Polyester Fabric" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-4 , June 2022, URL: https://www.ijtsrd.com/papers/ijtsrd50248.pdf Paper URL: https://www.ijtsrd.com/chemistry/other/50248/synthesis-characterization-and-dyeing-performance-of-novel-bisazobisazomethine-disperse-dyes-on-polyester-fabric/d-m-patel
This document summarizes a study that investigated the effect of benzoylation on the properties of acid dyes derived from H-acid (1-napthol-8-amino-3,6-disulphonic acid) applied to nylon 6.6 fabric. Twelve dyes were synthesized by coupling six primary aromatic amines with H-acid, and another twelve dyes were synthesized by coupling the same amines with benzoylated H-acid. The benzoylated acid dyes produced brighter shades on nylon 6.6 and had higher wet fastness properties due to their higher molecular weight. They also exhibited good exhaustion properties. Spectroscopic analysis showed the benzoylated dyes had
Basic dyes are positively charged molecules that strongly bind to negatively charged fibers like wool and silk. Their dyeing requires various auxiliaries to improve levelness and exhaustion. Key auxiliaries include wetting agents to spread dye in water, acetic acid to maintain pH for cationic dyes, chelating agents to remove metal ions, and retarders like polyacrylamides or electrolytes to slow dye uptake for even coloring. Proper use of auxiliaries enhances dyeing efficiency and quality for basic dyes.
The document discusses water quality assessment and surveillance. It outlines various physical, chemical and biological parameters used to evaluate drinking water quality according to WHO guidelines. These include turbidity, total dissolved solids, colour, odor, taste, temperature, pH and presence of inorganic constituents like chloride, calcium, magnesium, iron and sodium. Methods for testing parameters like turbidity, chloride, hardness, iron and fluoride are described. The document also covers bacteriological indicators of water quality including coliforms, E. coli and presence of pathogens. It provides methods for testing coliform bacteria using membrane filtration and multiple tube techniques.
This document discusses cytologic staining techniques, focusing on the Papanicolaou stain. It describes the multi-step Pap stain process including fixation, nuclear staining with hematoxylin, cytoplasmic staining with orange G and EA counterstains, clearing, and mounting. The document provides details on hematoxylin and the factors that influence its staining properties. It also discusses the cytoplasmic counterstains orange G and EA and the purpose of clearing in the staining process.
The document discusses various digital printing technologies, focusing on inkjet printing methods. It describes two main inkjet technologies: continuous inkjet (CIJ) and drop on demand (DOD). CIJ uses a continuous stream of ink broken into droplets through pressure, while DOD only deposits ink droplets when needed in response to digital signals. Common DOD methods are thermal bubble jet and piezoelectric, while CIJ includes single and multiple jet systems using deflection plates or air jets. The document compares the advantages and disadvantages of each technology.
4. essential elements for inkjet printingAdane Nega
This document discusses the essential elements required for inkjet printing of textiles. It outlines the necessary hardware including computers, software, printers, and fabric pre-treatment machines. It also discusses ink requirements including formulations for different fiber types and extended color gamuts. Finally, it addresses challenges in commercializing the technology such as printing speeds and the need for post-treatments, while envisioning future possibilities like mass customization and integration with other technologies.
This document discusses methods for high temperature dyeing of wool-polyester blends to minimize damage to the wool. It recommends using formaldehyde or similar agents to protect the wool at temperatures up to 120°C. Specific dyeing times and temperatures are provided for different levels of wool protection. One-bath and two-bath dyeing methods are described that allow deep shades while reducing staining of the wool component. Considerations for dye selection, recipes, and procedures are provided to optimize results while minimizing wool degradation.
This document summarizes the key properties and processes involved in dyeing cotton with vat dyes. Vat dyes are insoluble in water but can be converted to a water-soluble form through a process called vatting, which involves reducing the dye and forming a salt. Cotton is dyed by first converting the vat dye to its soluble form, dyeing the cotton, then reoxidizing the dye inside the fiber. The document outlines the chemical classes of vat dyes and the steps involved in vat dyeing cotton fabric using exhaust or continuous methods.
The document discusses various methods for dyeing polyester fibers, including:
1) Batch dyeing without carriers involves dyeing at a boil without additives to help penetration.
2) Carrier dyeing uses compounds to swell the fibers and allow deeper dye penetration.
3) High temperature, high pressure (HTHP) dyeing penetrates dye rapidly at 120-130°C without carriers.
4) Continuous thermosol dyeing involves padding, drying, and fixing dye within fibers at 190-220°C.
The document discusses various digital printing technologies, focusing on inkjet printing methods. It describes two main inkjet technologies: continuous inkjet (CIJ) and drop-on-demand (DOD). CIJ uses a continuous stream of ink broken into droplets through pressure, while DOD only deposits ink droplets when needed in response to digital signals. Common DOD methods are thermal bubble jet and piezoelectric, with the latter providing higher resolution and suitability for wider ranges of inks. The technologies each have advantages and limitations for different applications like textile printing.
This document compares and contrasts analog and digital printing technologies. It discusses the advantages and disadvantages of each, such as analog printing being better for mass production while digital is more suitable for variable, personalized, or short print runs. The document also examines factors to consider when choosing a printing method like image quality, production speed, and cost. Additionally, it describes how some systems combine analog and digital to leverage the strengths of both.
4. essential elements for inkjet printingAdane Nega
This document discusses the essential elements required for inkjet printing of textiles. It outlines the necessary hardware including computers, software, printers, and fabric pre-treatment machines. It also discusses ink requirements including formulations for different fiber types and extended color gamuts. Finally, it addresses challenges in commercializing the technology such as printing speeds and the future potential of digital printing for mass customization and integrated production systems.
The document discusses various methods for dyeing polyester fibers, including:
1) Batch dyeing without carriers involves dyeing at a boil without additives to help penetration.
2) Carrier dyeing uses compounds to swell the fibers and allow deeper dye penetration.
3) High temperature, high pressure (HTHP) dyeing penetrates dye rapidly at over 120°C without carriers.
4) Continuous thermosol dyeing involves padding, drying, and fixing dye within fibers at 190-220°C.
This document discusses methods for high temperature dyeing of wool-polyester blends to minimize damage to the wool. It recommends using formaldehyde or similar agents to protect the wool at temperatures up to 120°C. Specific dyeing times and temperatures are provided for different levels of wool protection. One-bath and two-bath dyeing methods are described that allow deep shades while reducing staining of the wool component. Post-treatment and troubleshooting steps are also outlined.
This document summarizes the key properties and processes involved in dyeing cotton with vat dyes. Vat dyes are insoluble in water but can be converted to a water-soluble form through a process called vatting, which involves reducing the dye and forming a salt. The water-soluble form dyes cotton fibers, and is then re-oxidized inside the fibers. The dyeing process involves steps of reduction, dyeing, oxidation, and soaping to achieve bright shades and fastness properties.
This document discusses the dyeing of polyamide fibers like wool, silk, and nylon. It explains the dyeing mechanisms and how the structure of polyamide fibers allows them to be dyed using different dye classes like acid dyes, chrome dyes, and reactive dyes depending on the desired properties like colorfastness. Factors like pH, temperature, and use of leveling agents affect dye uptake and uniformity. Different types of acid dyes provide varying colorfastness and are suitable for different applications depending on those properties.
The document discusses different types of textile printing methods. It begins by distinguishing between dyeing and printing, noting that dyeing results in uniform coloration while printing applies color locally in designs. It then covers various printing styles like direct, resist, and discharge printing. The document concludes by describing common printing methods such as block, stencil, roller, screen, and digital printing.
There are key differences between dye and pigment printing. Pigments have no affinity for fibers and are insoluble in water, requiring a binder to fix them onto fibers. Dyes have affinity for fibers and are water soluble. Pigment printing uses a binder that is an aqueous emulsion copolymer which polymerizes during curing to form a strong film embedding the pigment and adhering it to the fiber. Suitable thickeners for pigment printing are emulsion or synthetic thickeners which do not interact negatively with the binder. Emulsion thickeners are prepared using oil, water, emulsifiers and other agents, while synthetic thickeners are high molecular weight copolymers that thicken when
The document discusses different types of textile printing methods. It distinguishes between dyeing and printing, noting that dyeing results in uniform coloration while printing applies color locally in designs. Printing uses an aqueous medium of high viscosity to prevent color from spreading. Common printing methods described include block, stencil, roller, screen, and digital printing. Resist and discharge styles of printing are also outlined.
Manual screen printing is a modified version of stencil printing that was developed in England in the 1830s-1840s and became popular in India in the 1920s. It remains most commonly used by small-scale printers. The process involves stretching a bolting cloth screen fabric tightly over a frame, coating it with a photosensitive emulsion, exposing the screen to a color-separated design to insolubilize the emulsion, and washing away the unexposed emulsion to create stencil openings. The screen is then ready to use to force ink through the stencil openings and transfer the design to fabric by moving a squeegee over the screen surface.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Assessment and Planning in Educational technology.pptxKavitha Krishnan
In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
1. REVISED PAPER
Dyeing of Cotton with Vat Dyes using Iron(II) Salt Complexes
J N Chakraborty, Department of Textile Technology, National Institute of Technology,
Jalandhar-144011
R B Chavan, Department of Textile Technology, Indian Institute of Technology,
New Delhi -110016, India
ABSTRACT
Sodium hydrosulfite is universally used reducing agent for dyeing of cotton with vat dyes.
However it forms various decomposition products containing sulfur, which go into wastewater
creating environmental problems. Search is therefore on for alternative reducing systems for vat
dyeing. In the present work, the use of the co-ordination complexes of Fe(II) salts with suitable
ligands is reported.
Key Terms
Hydrosulfite, Dye Strength, Fe(II) salt, Ligand,
Vat colors possess pairs of carbonyl (C=O) groups in their structure and are water insoluble.
These are converted to water soluble form in presence of strong reducing agent and alkali which
only then exhibit affinity for cellulosics1,2. Sodium hydrosulfite is universally used reducing
agent for dyeing of cotton with vat dyes. However, there are certain drawbacks associated with
use of sodium hydrosulfite viz. reduction and dyeing both are performed at different temperature
for different classes of vat dyes2 ; wastage of sodium hydrosulfite due to its thermal and
oxidative decomposition in bath, which is compensated by means of adding it in excess3,4 (a cost
factor), as well as formation of various decomposition products containing sulfur, which go into
waste-water creating environmental problems5,6 .
2. Various alternative eco-friendly reducing systems viz. hydroxy acetone7,8, glucose-NaOH9,
electrochemical reduction10-11 are reported in the literature. Fe(OH)2, though a strong reducing
agent, its reducing capacity is not revealed due to its poor water solubility. In order to use
Fe(OH)2 as reducing agent it is necessary to keep it in solution. This is possible by the formation
of co-ordination complexes of Fe(II) salts with suitable ligands in presence of alkali like NaOH.
It was reported that gluconic acid co-ordinates with Fe(II), improves its water solubility to
generate reduction potential for vat dye reduction and subsequent dyeing of cotton at 60oC5. In
our previous work, we had shown that Fe(II) salts can be successfully complexed with tartaric
acid, citric acid or triethanolamine in presence of NaOH12. These co-ordination complexes were
termed as single ligand complexes or single ligand systems. These Fe(II)–single ligand
complexed reduction baths were turbid due to incomplete solubilisation of Fe(OH)2 ; though
effective for reduction of indigo were ineffective for other vat dyes12 .
The present paper aims at the use of co-ordination complexes of Fe(II) salts with two ligands
(viz. citric acid and triethanolamine or tartaric acid and triethanol amine, termed as two ligand
systems) along with NaOH for reduction and application of vat dyes other than indigo on cotton
at room temperature. Fe(II) complexed with gluconic acid was also used for dyeing at 60oC as
reported in literature5 to compare with the dyeing efficiency of our system.
EXPERIMENTAL
Materials (with specifications), determination of alkali equivalence of ligands, calculation of
total NaOH requirement, measurement of color strength of samples, measurement of reduction
potential, estimation of iron in dyed samples, estimation of ferric iron, estimation of soluble iron
in dyebath were reported in earlier paper12. Commercial vat dyes were used. C.I.Generic names
are reported in this paper13.
2
3. Preparation of Reduction Bath
Single Ligand System
2.16g of tartaric acid or 3.0g of citric acid or 5.6ml of gluconic acid (50%) or 1.92ml of
triethanolamine was dissolved in 100 ml water in a glass beaker in open air ; 2 g of FeSO4 was
dissolved in this bath ( FeSO4 : ligand = 1 : 2 molar ) followed by addition of NaOH ( 1.47g,
2.62g or 1.21g for tartaric, citric or gluconic acid system respectively ). All the baths were turbid.
Quantity of dye required to get 1% shade was then added. Vatting and dyeing were carried out
at room temperature, except gluconic acid bath which was heated up at 60oC as reported in
literature12.
Double Ligand System
3.78g of tartaric or 6g of citric acid was dissolved in 50 ml water in a glass beaker in open air
followed by addition of 2g of FeSO4 with constant stirring till the latter gets completely
dissolved. Triethanolamine was added in this solution (1ml in tartaric and 1.5ml in citric acid
system) and stirred well to ensure thorough mixing. In another beaker, desired weight of NaOH
( 3.09g for tartaric and 4.3g for citric acid system ) was dissolved in 50 ml water followed by
addition of this NaOH solution to the previously prepared FeSO4, tartaric (or citric) acid and
triethanolamine mixture. A clear solution was obtained. Quantity of dye required to get 1%
shade was added to this bath. Instantaneous reduction of dye occurs (though 10 minutes were
allowed to ensure complete reduction). The vatting and dyeing were carried out at room
temperature at material to liquor ratio of 1:20
Sodium hydrosulfite system
Concentrations of hydrosulfite, NaOH and vatting and dyeing conditions were as follows1,2 :
3
4. IK IW IN IN special
Temperature of vatting 35-40oC 45-50oC 55-60oC ≥ 60oC
Temperature of dyeing 35oC 45oC 50-55oC ≥60oC
Hydrosulfite (g/l) 8 10 12 15
NaOH (g/l) 8 10 12 15
Dyeing of Samples
Cotton fabric samples were dyed in open air in glass beakers for 1 hr. at room temperature in
single and double ligand reducing systems separately, at 60oC in gluconic acid system and at
specific temperature range in hydrosulfite system. Dyed samples were air oxidized, rinsed with
water, soaped at boil with anionic detergent (5g/l) for 15 minutes followed by thorough washing.
Wash and light fastness were determined as per standard procedure reported in Bureau of Indian
Standards( Test methods IS: 764 : 1979 and IS 2454 : 1985 respectively)14. Color strength was
measured in Datacolor Color Matching Instrument.
RESULTS AND DISCUSSION
For the simplicity of understanding the co-ordination complex system essentially consisting of
Fe(II) salt like FeSO4, NaOH and ligands like citric acid, tartaric acid or triethanolamine either
alone (single ligands) or tartaric acid and citric acid separately in combination with
triethanolamine (two ligands), it is envisaged that FeSO4 reacts with NaOH with formation of
Fe(OH)2 of poor water solubility. Its water solubility is improved when Fe(II) forms co-
4
5. ordination complex with single ligand or two ligands as mentioned above. In the following
paragraphs such co-ordination complexes are referred as single ligand or two ligand systems.
Dyeing of Cotton with Anthraquinoid Vat Dye
Single Ligand System
Reducing systems based on Fe(OH)2 complexed with single ligand though worked successfully
for dyeing of cotton with indigo12, showed their inability to reduce anthraquinoid vat dyes except
gluconic acid system. Table 1 shows values of pH, reduction potential, complexed iron and dye
strength of samples. It was observed that no dye reduction took place from FeSO 4 + NaOH as
well as FeSO4 + NaOH + triethanolamine systems, hence no dye yield. In case of tartaric and
citric acid systems, partial reduction of dye was visually observed, however there was no dyeing,
whereas in case of gluconic acid system dye reduction and dyeing took place, though the
reduction potential at all stages of dyeing was highest in triethanolamine system.
Different ligands showed varying amounts of complexed Fe(II) in bath before dye addition, as
shown in Table I. Complexed Fe(II) was least in FeSO4 + NaOH system and highest in gluconic
acid system. Thus it appears that the amount of complexed Fe(II) in triethanolamine system was
not adequate for vat dye reduction and therefore no dyeing took place. Complexed Fe(II)was
higher in case of tartaric and citric acid systems ; thus when dye was added to these reducing
systems, partial reduction of vat dye was observed but no dyeing took place. In contrast, in
gluconic acid system complexed Fe(II) was highest causing complete reduction of vat dye and
good dyeing. Failure of anthraquinoid vat dye reduction and its subsequent dyeing in spite of
high reduction potential and pH of baths at different stages of dyeing clearly indicated that it was
not only the reduction potential but also amount of complexed Fe(II) in bath was equally
important for dye reduction and to keep the dye in reduced form during dyeing.
5
6. Chemically vat dyes can be classified in two types - indigoid and anthraquinoid. Indigoid vat dye
can be reduced and maintained in reduced condition at low reduction potential (-700 mV)
compared to anthraquinoid vat dyes -(850-900)mV. Therefore a single ligand system was
capable of reducing indigo and keeping it in reduced condition giving good dyeing of cotton 12
but the same systems failed to reduce anthraquinoid vat dyes. This analysis made it clear that the
dyeing of cotton with vat dye did not occur from co-ordination complexes of Fe(II) with single
ligand systems (except gluconic acid) due to inadequate complexion of Fe(II). It was therefore
thought to use two ligand systems for vat dyeing.
Chakraborty replace the words highlighted with unstable co-ordination complex of Fe(II)
Two Ligand Systems
Limited complexion of Fe(II) in presence of single ligand like tartaric or citric acid might be due
to formation of weak co-ordination linkages with limited stability. It was thought that a second
ligand like triethanolamine may enter along with tartaric and citric acid in co-ordination linkage
with Fe(II), resulting in more stable complex. Based on this assumption, reduction baths
consisting of FeSO4-tartaric acid-triethanolamine-NaOH or FeSO4 -citric acid - triethanolamine -
NaOH ( FeSO4 -25 g/l, Tartaric acid or Citric acid-15 g/l, Triethanolamine - 40 ml/l and
NaOH-50 g/l) were prepared so as to get colorless, clear reduction baths indicating complete
complexion of Fe(II). In these formulations, molar ratio of FeSO4 with triethanolamine was 1: 3,
that with tartaric acid 1: 1.5 and with citric acid 1 : 1. Dyeing with few randomly selected vat
dyes was carried out in 1% shade at room temperature and were compared with those obtained
from hydrosulfite system. Results are shown in Table II. Except C.I. Vat Blue 7 and C.I. Vat
Violet 1, the dyeings were comparable to sodium hydrosulfite system.
6
7. This observation gave support to our hypothesis that for satisfactory dyeing with vat dyes, it was
not only the reduction potential at different stages of dyeing but also maximum complexion of
Fe(II) are very important.
Chakraborty Replace the highlighted portion by: the formation of stable co-ordination complex
of Fe(II) is important
Optimisation of Dyebath Recipe for Double Ligand Systems Replace double by two
The above experiment gave the clue for successful dyeing of cotton with vat dyes using Fe(II)
complexes as reducing agent. Subsequently, concentration of each component in double ligand (
replace by two) reducing systems was optimized. Concentration of total NaOH required and
alkali equivalence of acidic ligands was explained in earlier paper12. Criteria for optimized
concentrations were those that produced clear solutions having maximum efficiency for dye
reduction and showing maximum dye uptake on cotton.
In FeSO4 - tartaric acid - triethanolamine - NaOH reducing system, the optimized reduction bath
composition was FeSO4-20 g/l, Tartaric acid-37.8 g/l (FeSO4: tartaric acid =1:3.5 molar),
Triethanolamine - 10 ml/l (FeSO4 : triethanolamine = 1: 0.7 molar) and NaOH-30.9 g/l ;
whereas in FeSO4-citric acid - triethanolamine - NaOH reducing system, the optimized reduction
bath composition was FeSO4 - 20 g/l, Citric acid - 60 g/l ( FeSO4 : citric acid =1 : 4.5 molar),
Triethanolamine - 15 ml/l (FeSO4 : triethanolamine = 1: 1.1 molar) and NaOH - 43 g/l . The
recipes stated in experimental section are based on these optimized concentrations.
Stability of Reduction Baths
Reduction baths with optimized concentration of chemicals were prepared in absence and
presence of dye and were stored in open air at room temperature for different intervals of time up
7
8. to 24 hours. Reduction potential was measured at definite intervals and is shown in Fig.1. All
the reduction baths remained fairly stable up to 4 hours, beyond which drop in reduction
potential started taking place. After storing for 24 hours, the drop in reduction potential was
substantial in all cases. The dyeability of reduction baths after storage for definite intervals was
studied by carrying out dyeing of cotton with C.I. Vat Green 1 (4% owf). Dye strength values
are shown in Fig. 2, which also indicated that baths remained stable up to 4 hours, beyond which
the stability went on decreasing. Comparison of dye strength indicated the bath stability in the
following order
Hydrosulfite < Citric acid, triethanolamine ligands ≃ Tartaric acid, triethanolamine ligands
< Gluconic acid ligand systems
Dyeing with different Vat Dyes
In order to establish the feasibility of new reducing systems for application of vat dyes, dyeing of
cotton with a wide range of vat dyes belonging to I K, IW, IN and IN special classes was carried out
for 4% shades. For comparison purpose, respective standards were prepared in hydrosulfite and
NaOH system. Dyeings were also carried out in gluconic acid system at 60oC using FeSO4:
gluconic acid (1: 2 molar) as reported in literature5 to compare efficiency of our systems. In case
of C.I. Vat Green 9 (Black BB), dyeings were carried out for 10% shades. Results obtained are
shown in Ttable III.
Dye belonging to IK class showed better color strength in two ligand systems compared to
hydrosulfite and gluconic acid systems. In case of IW, IN and IN special classes, no definite trend was
observed. Hydrosulfite and gluconic acid systems produced good black shades with Black BB,
whereas two ligand systems produced deep olive green shade instead of a black
8
9. From these observations it may be concluded that two ligand systems (tartaric, triethanol amine
and citric acid, triethanol amine) investigated in the present work in principle were suitable for
most of the vat dyestuffs. Few dyes particularly blues showed less color strength probably due to
over-reduction problem associated with structure of these dyes (indanthrone type) and black BB
did not give black shade.
Fastness Properties of Dyed Samples
Wash and light fastness tests were carried out on few selected dyed samples to confirm if
presence of iron interferes in their fastness properties. While wash fastness properties remained
unaffected for all dyed samples in all reducing systems, light fastness in case of C.I. Vat Brown 3
was lowered in case of Fe(II) complexes, might be due to presence of iron, which showed
catalytic action on dyed samples (table IV). In order to confirm this, estimation of residual iron
was carried out on dyed samples. It was found that negligible amount of iron was deposited on
dyed sample in gluconic acid system whereas higher amounts were deposited on samples dyed
from tartaric and citric acid systems (table V). Presence of iron on dyeing might show catalytic
action in presence of light, but this problem is restricted to certain red, yellow and brown dyes
only1.
CONCLUSIONS
Reducing systems based on Fe(II) complexes with single ligand such as tartaric acid, citric acid
or triethanolamine were not suitable for dyeing with vat dyes. However, Fe(II) complexes with
two ligands produced dyeing comparable to sodium hydrosulfite system with few exceptions.
Blue vat dyes with indanthrone structure produced weaker dyeing due to over reduction, whereas
C.I. Vat Green 9 produced deep olive green shade instead of black. Wash fastness of five vat
9
10. dyes under investigation was comparable to literature values, whereas there was deterioration in
light fastness in case of C.I. Vat Brown 3.
References
1. M. R. Fox, Vat Dyestuffs and Vat Dyeing, 1st edition, Chapman & Hall Ltd, London, 1948,
pp97 - 100.
2. S.V.Gokhale, and R.C.Shah, Cotton piece Dyeing, 1st edition, Ahmedabad Textile Industries
Research Association, India, 1974, pp30-35.
3. G. P. Nair and S. S. Trivedi, Colourage, Vol. 17, No. 27, December 1970, pp19-21.
4. F. Shadov, M. Korchagin and A. Matetsky, Chemical Technology of Fibrous Materials,
Revised English Translation, Mir Publishers, Moscow, 1978, pp428-433.
5. B. Semet, B. Sackingen and G. E. Gurninger, Melliand Textilberichte, Vol. 76, No.3, March
1995, pp161-164.
6. D. Fiebig and K. Konig, Textile Praxis International, May 1977, pp 577- 586.
7. E. Marte, Textil Praxis, Vol. 44 , No. 7, July 1989, pp737-738.
8. U. Baumgarte, Melliand Textilberichte, Vol. 68, No. 3, March 1987 , pp189- 195.
9 N. Nowack, H. Brocher, U. Gering and T. Stockhorst, Melliand Textilberichte, Vol. 63, No. 2,
February 1982, pp134-136.
10. T.Bechtold, E. Burtscher, D. Gmeiner and O. Bobleter, Melliand Textilberichte, Vol. 72,
No.1, January 1991, pp50-54.
11. T.Bechtold, E. Burtscher, G. Kuhnel and O. Bobleter, Journal of the Society of Dyers &
Colourists, Vol. 113, No. 4, April 1997, pp135-144.
12. R. B. Chavan and J. N. Chakraborty, Coloration Technology, Vol. 117, No.2, February 2001,
pp88-94.
13. Colour Index International, 3rd edition (3rd revision), Society of Dyers & Colourists,
Bradford, 1987.
14. Handbook of Textile Testing, Part-4, 1st Revision, Bureau of Indian Standards, New Delhi,
1988, pp115-119 & 141-142.
Authors Address:
Dr. J.N Chakraborty, NIT, Jalandhar, India Dr. R.B. Chavan, IIT, New Delhi, India
10
11. E-Mail –chakrabortyjn@hotmail.com E-Mail - rbchavan@hotmail.com
Tel : 95-181-2690301-2, Ext. 221 Tel : 95-11-26591406
Fax: 95-181- 2690320 Fax: 95-11-26581103
11