Bifunctional Dyes Research Articles

Kinetics of Decolorization of Reactive Textile Dye via Heterogeneous Photocatalysis Using Titanium Dioxide

The textile industry is known for its excessive water consumption and environmental impact. One of the major challenges it faces is managing pollution generated by dyes, particularly bifunctional dyes, such as sumireact supra yellow s-hbu, with a red appearance and sumifix supra lemon-yellow e-xf, with a yellow appearance. This study aimed to investigate the decolorization kinetics of synthetic solutions of said bifunctional dyes, which comprise triazine and vinylsulfon. We conducted various tests, including modifications of pH, the addition of TiO2 P-50 nanoparticles, exposure to solar radiation, limited contact with oxygen, and eolic agitation. The initial solutions had a concentration of 1000 ppm of textile dye. The study showed that the reaction order for the “red” solutions in the R6 and R9 reactors and all the yellow solutions was ½. The concentration of nanoparticles and pH had a significant impact on the reaction rate. The yellow solutions with a concentration of 800 ppm and pH levels of 3.15, 4.13, and 2.25 demonstrated 100% color discoloration, followed by solutions with a concentration of 400 ppm and pH levels of 3.15, 2.25, and 4.13. The analysis of variance confirmed the reaction rate constants for the yellow solutions and emphasized the significance of pH in this process.

STUDY OF THE PROPERTIES OF SURFACE-ACTIVE SUBSTANCES DETERMINING THE EFFICIENCY OF DYING AND RINSING OF TEXTILE MATERIALS

The article studies the most important properties of surfactants – foaming and wetting ability, stability in a highly alkaline environment, surface activity. Spectrophotometric method showed the intensifying effect of environmentally friendly surfactants Glucopon 2015 and Carboxypav on the process of colouring natural textile materials with dichlorotriazine, vinyl sulfone and bifunctional dyes. The effect of surfactants of various structures on the state of the active dye in solution and the technical results of colouring cellulose and cotton silk fabrics has been evaluated. A synergistic effect of the solubilising action of surfactants – nonionic alkyl polyglycosides (Glucopon 215) and anionic carboxylates (Carboxypav) on active dyes was revealed.

Synergistic role of aluminium sulphate flocculation agent as bi-functional dye additive for Dye-Sensitized Solar Cell (DSSC)

In this study, an organic dye sensitizer derived from blackberry fruits was employed, and the influence of aluminium sulphate, Al2(SO4)3·H2O (alum) as a bi-functional (acidification and flocculation) additive in DSSC was investigated. The alum treated dye solution, ATD, was created by adding 0.1 g alum to the dye solution prior to the immersion operation. As reference, an untreated dye solution, UD, was created for comparative purposes. The TiO2 photoelectrodes were characterized through FESEM, EDXs, and XRD techniques, while the dye properties were investigated using UV-Vis and FTIR. Finally, I-V characteristic, IPCE and EIS measurements were used to assess the overall performances of DSSCs. Based on the findings, the photocurrent-voltage conversion efficiency of the ATD, and the non-treated (UD) dye sensitised DSSCs were found to be 0.64 ± 0.02% and 0.44 ± 0.02%, respectively. The role of alum in regulating the acidity of the blackberry dye solution in the ATD photoelectrode mimics the acid treatment process on TiO2 nanoparticles. Furthermore, the purification process of natural dye solution by the flocculation reaction of crude impurities (sugar, protein, etc.) purifies the dye solution even further. The ATD DSSC outperformed the UD by 45.50 ± 0.02% as a result of these combined effects.

Template-directed conjugation of heterogeneous oligonucleotides to a homobifunctional molecule for programmable supramolecular assembly.

Nanoscience aspires to mimic nature's control over functional molecular assemblies. Here we present a templating technique for the efficient attachment of two different oligonucleotides to a homobifunctional molecule, enabling its controlled and programmable placement within a DNA nanostructure. We demonstrate its application to a range of organic molecules with different conjugation chemistries and water solubilities. We show that the two oligonucleotide adapters can be used to integrate a bifunctional cyanine dye into a self-assembled three-dimensional DNA origami nanostructure, giving control of both position and orientation. We also demonstrate the use of both adapters to exert dynamic control over the environment of the target molecule by means of a series of strand-displacement reactions.

Optimization of Enzymatic Treatment and Reactive Dyeing of viscose fabric in One-bath Process

Conventional pretreatment and dyeing processes of viscose fabric are mainly conducted in two baths with substantial amounts of water and auxiliaries. These processes comprise one bath of two–stages for enzymatic de-sizing and alkaline treatment adopted using sodium carbonate with peroxide bleaching formulations and a second bath for the dyeing process. In this study, a regular viscose woven fabric was initially pretreated with a commercial desizing enzyme and subsequently dyed with different reactive dyes in the same exhaust bath process. The effect of one-bath enzymatic pretreatment and reactive dyeing was investigated and optimized, employing enzyme and mono- and/or bifunctional reactive dyes at various concentrations.The results showed that the one-bath pretreatment and dyeing process could be performed successfully, exhibiting remarkable colour strength and excellent performance equal to that with the conventional pretreatment and dyeing method. Both the pretreated fabrics via the bio-method and the conventional one exhibited approximately equal efficiency in terms of improved dyeing and fastness properties. The bifunctional reactive dyes, RR 195 and RBl 5, exhibited higher degrees of dye exhaustion and total fixation yield than those of the monofunctional reactive dyes, RR 180 and RR 31. Although the shorter the one-bath enzymatic pretreatment and dyeing process, all the reactive dyeings using this Bio-method showed comparable CIE L*b*a* and colour difference values E to the conventionally dyed sample using Conv-method, particularly in the case of bifunctional dyes.

Synthesis and application of novel reactive dyes based on Dimedone moiety

The purpose of this paper is to synthesis, characterize and find out properties of some new bifunctional dye Bis (monochlorotriazine) (MCT) and heterobifunctional (monochlorotriazine / sulphatoethylsulphone) (MCT/SES) reactive dyes using Dimedone moiety (5,5-Dimethylcyclohexane-1,3-dione) bearing good color strength, lightfastness, and other favourable properties. The first dye A is synthesized and coupled with diazonium salts having the reactive groups. But the second dye B is synthesiezed of Dimedone moiety (2-amino4,4-dimethy,3-cyano,6-oxo-beno[b] thiophene) then diazotized and coupled with 1-amino-8-naphthol-3,6-disulphonic acid (H-acid) to produce mono azo intermediate. Such product products reacted with 2,4,6-trichloro-1,3,5-triazine in 1:1 molar ratio afforded via nucleophilic displacement with 1,4-phenylenediamine in 2:1 molar ratio to give bis monochlorotriazine reactive dyes thus yielding the new target reactive. The synthesized dyes were applied onto cotton, silk and wool fabric under the typical exhaust dyeing conditions and their dyeing properties were investigated. The results assessed for dyeing indicate high quality dyeing properties However, the homobifunctional (bis MCT) dyes showed higher exhaustion and fixation values, color yield and fastness properties than heterobifunctional (MCT/SES).

Bifunctional Dye Molecule in All‐Inorganic CsPbIBr2 Perovskite Solar Cells with Efficiency Exceeding 10%

Inorganic lead halide perovskites are attracting increasing attention due to their much better thermal stability than the organic–inorganic hybrid perovskite materials. Thus, the low power conversion efficiency (PCE) is a key issue for the inorganic lead halide perovskite solar cells (PSCs). This is mainly due to their wider bandgap and larger energy loss (Eloss) in the devices. Herein, for solving this issue, a dye molecule‐assisted engineering using the dye of 5,15‐bis(2,6‐dioctoxyphenyl)‐10‐(bis(4‐hexylphenyl)‐amino‐20‐4‐carboxyphenylethynyl)porphyrinato]zinc(II) (YD2‐o‐C8) is demonstrated. Results indicate that this molecule has a bifunctional effect, not only as a co‐sensitization layer for CsPbIBr2 with broader absorption spectrum but also reduces the Eloss by interface passivation. Specifically, the light absorption range of the photoactive layer is broadened from 600 to nearly 680 nm. At the same time, the interfacial charge recombination is highly reduced. After optimizing, the champion PCE is enhanced from 7.02% to 10.13%, and record‐high open‐circuit voltage (VOC) of 1.37 V and short‐circuit currents (JSC) of 12.05 mA cm−2 are achieved. This study opens a simple and efficient way to improve the efficiency of inorganic PSCs.

Uklanjanje hidrolizovane reaktivne boje sa pamučne tkanine nakon bojenja

Removal of hydrolysed reactive dye is an important stage in cotton dyeing as it affects the exploitation and hygienic properties of textile products. As a major consumer of water and chemicals, this work process is being studied from the point of view of saving natural resources and environmental protection. In this paper, studied was the effect of washing agents on the basis of surfactants with different ionogenicity as well as pure water on the removal of hydrolyzed reactive dyes having different functional groups. The obtained results suggest that clean water with a larger bath ratio (1:30) and a washing time of 30 min can be an effective remover for hydrolysed monoreactive dye. In the removal of the hydrolysed bifunctional dye, beside the bath ratio and washing times, the concentration of surfactants can also have a significant effect on the process efficiency.

A study of reusing vinyl sulfone based reactive dye for dyeing cotton fiber

Reactive dye is a popular dye for dyeing cotton fiber due to its very good color fastness which is explained by the formation of covalent bond between dye and fiber. In this study, practicality of reuse of reactive dye by compensating for the hydrolyzed part of the dye solution is examined. A monofunctional dye (vinyl sulfone type) was used and it was found that dyeing cotton fiber with reused dyebath is possible. Since bifunctional dye can improve the chance of dye-fiber bond formation, vinyl sulfone based bifunctional reactive dyes were also selected in this study. Three types of bifunctional dyes were used and they basically share the same vinyl sulfone group; other reactive groups are monochlorotriazine, dichlorotriazine and vinyl sulfone. Such dyes were chosen in order to compare their respective efficiencies under the effect of one common reactive group. The aim of this study was to compare the effect of hydrolyzed and unhydrolyzed proportions of mono-and bifunctional reactive dyes on cotton fiber and study the possibility and efficiency of the two different reuse dyebath systems.

Naphthoylenebenzimidazolone dyes as one‐component photoinitiators

The appropriate substituents have been added to a 7H‐benzimidazo[2,1‐a]benz[de]isoquinolin‐7‐one skeleton in order to obtain a one‐component initiator system. The absorption, fluorescence, and electrochemical properties of these naphthoylenebenzimidazolone dyes and their usefulness as visible light initiators of free radical polymerisation of trimethylolpropane triacrylate were examined. The initiation efficiency of these dyes was compared with that of the parent 7H‐benzimidazo[2,1‐a]benz[de]isoquinolin‐7‐one in the presence of a coinitiator. Results show that these bifunctional dyes are able to initiate polymerisation without an additional coinitiator. Photopolymerisation studies and the relationship between the rate of polymerisation and the free energy change for electron transfer revealed that, depending on the concentration, initiating radicals are generated via intra‐ and intermolecular electron transfer.

UV-grafting coloration of cotton and wool fabrics using bismethacrylated quinizarin dye

A novel bifunctional quinizarin dye possessing two photoactive methacrylate groups was synthesized by the reaction of quinizarin with methacryloyl chloride. The synthesized dye, a low substantive dye under the conventional dyeing process, can be photografted onto cotton and wool fabrics at room temperature without neutral salts, which makes it a novel coloration process of excellent environmental friendliness. The concurrent polymerization and grafting of the synthesized dye onto cotton or wool can be assisted by a photoinitiator and acrylic acid in the case of cotton grafting. Moreover, color yields of the grafted fabrics improved significantly with the photografting of the bifunctional dye. The bifunctional dye can be photopolymerized with the increase in UV energy to 25 J/cm2 and the oligomeric dye has a degree of polymerization of 5 or more. Furthermore, the color fastness properties of the grafted fabrics were superior to those of the dyed fabrics via exhaustion.

An Investigation into the In situ Preparation of Hetero Bifunctional Monochlorotriazinyl-Vinyl Sulphone Reactive Dyes for Cotton

An attempt has been made in in-situ preparation and application of two isomers (para and meta) of aminophenyl-b-sulphatoethyl sulphone reagents (PABSES and MABSES) with three dichlorotriazinyldyes i.e. CI Reactive Orange 86, CI Reactive Red 11 and CI Reactive Blue 168 to generate mixed hetero bifunctional dyes in dye bath. Dyeing results when compared with similar targeted type of commerciallyavailable Sumifix Supra dyes were found not up to the mark. Build up properties of all in situ prepared dyes were lower except for few light depth of shades as compared to preformed commercial Sumifix Supradyes. This could be because of inefficient condensation of dichlorotriazinyl dyes with the aminophenyl- b-sulphatoethyl sulphone. However, meta isomer of aminophenyl-b-sulphatoethyl sulphone appeared tobe more effective than the para isomer.

Bifunctional Rhodamine Linker Simplifies Colocalization Studies in Single-Molecule Imaging

Xanthene dyes (e.g., fluoresceins, rhodamines and rhodols) containing linkers for bio-conjugation are used extensively as fluorescent labels and probes to study biological systems. We have synthesized unsymmetrical, single isomer, bright, photostable rhodamine dyes. The asymmetric nature of the dye allowed us to introduce two independent functional groups into the rhodamine dye system. This, in turn, enabled us to generate a biotinylated and fluorescently-labeled protein, ready to be immobilized onto a streptavidin-coated surface for imaging.We demonstrated the utility of this bifunctional dye in a simple colocalization experiment. We showed that that by using anti-NGAL antibody attached to the biotin-linked rhodamine dye (bt-Rh-mAb), we can easily determine the surface density of this capture antibody on a glass slide. We reacted several different concentrations of bt-Rh-mAb onto a streptavidin surface, washed, and took single-molecule images. Simply counting the fluorophores generated a good estimate of the surface concentration of capture antibody. Without the fluorescent label, the surface concentration of the capture antibody must be either assumed or determined through a more complex and less direct process. We also conducted binding experiments using Cy5-labeled NGAL under equilibrium conditions. This colocalization measurement provided the fraction bound and thus a quick estimate of the dissociation constant.Lastly, we performed a sandwich immunoassay utilizing the bt-Rh-mAb capture antibody and a Cy5-labeled detection antibody. Colocalization analysis provided the analyte concentration and simultaneously reduced the contribution of nonspecific surface binding since “Cy5-only signals” were excluded. The bifunctional rhodamine linker is therefore a useful reagent to simplify a wide range of single-molecule experiments.

Degradation of Reactive Yellow 145 dye by persulfate using microwave and conventional heating

Degradation of C. I. Reactive Yellow (RY 145), a bi-functional dye containing azo chromophore has been attempted in the presence of potassium persulfate (KPS) as an initiator in the presence of microwave irradiation. The conditions of degradation were optimized and its kinetics was studied. Complete dye degradation was observed in 3600 and 280 s, respectively, using conventional and microwave heating at the original pH (5.8) of the dye solution with COD removal of 60 and 66.5%. Under optimized conditions, efficiency of H2O2 was also compared for degrading the dye. Pseudo-first-order kinetics with higher kinetic rate constant (0.0165 × 102s−1) and maximum energy efficiency (67.6%) was achieved through microwave assisted KPS system. Additional benefit of microwave approach was accrued by the extensive reduction in electrical energy consumption by 10638.32kWh/m3. The effect of addition of SO42− and CO32− anions to the dye solution has indicated that the former enhances the degradation, whereas the latter reduces it. The temperature study using Arrhenius equation indicated decrease in the activation energy for the microwave system along with 2.6 times higher frequency factor than that for conventional heating. Thus, the microwave radiation assisted KPS system has been found to be the most cost effective and environmentally benign for the dye degradation process.

The contribution of different vinyl sulphone-reactive dyes to an effluent

Three types of vinyl sulphone dyes were measured in the effluent in this study. The selected dyes were Remazol Yellow RR (mono-functional), Remazol Blue RR (homo bi-functional) and Remazol Red RR (hetero bi-functional). The extinction coefficients of these dyes were measured by creating absorbance versus concentration curves. The absorbance values were obtained by testing standard solutions of each dye in a UV–visible spectrophotometer. The dyeing process was carried out at 4 different dye concentrations (0.025g/40ml, 0.05g/40ml, 0.10g/40ml and 0.15g/40ml) on a 5-g fabric sample for each of the dyes. The post-dye liquors and post-wash liquors were tested in an UV–visible spectrophotometer, and their concentrations were calculated using the Beer–Lambert law. The contribution of these dyes to the effluent was calculated and compared, and their adsorption isotherms (Langmuir and Freundlich isotherm) were analysed. The homo bi-functional dye (Blue RR) performed well in the dye bath, but it contributed significantly to the effluent during the washing stages. The mono-functional dye (Yellow RR) was able to adsorb, but it did not perform well due to its greater heterogeneity. The hetero bi-functional Red RR dye was found to be the most environmentally friendly in comparison with the other vinyl sulphone dyes.

Comparison of different wastewater treatments for colour removal of reactive dye baths

The generation of high-coloured wastewater is one of the main environmental problems of the textile industry. Reactive dyes are widely used in the dyeing of cellulosic fibres. However, they have low exhaustion degree (70–90%). The degradation of residual dyes by aerobic biological treatment is very poor, being necessary the application of specific treatments. In this work, three different methods for the removal of reactive dyes were compared: electrochemical treatment, coagulation with Moringa oleifera waste and enzymatic treatment with laccase. Two azo bifunctional dyes with different reactive groups were selected: C.I. Reactive Black 5 (vinyl sulphone) and C.I. Reactive Red 231 (chlorotriazine). The influence of pH (5 and 9) and dye hydrolysis on the decolourisation yield was studied. The electrochemical treatment was the most efficient, with 95–100% colour removal yield. The coagulation with M. oleifera waste also achieved high colour removal efficiency (91–94%). Both methods showed an independent behaviour with respect to pH or dye hydrolysis. The enzymatic treatment should be performed at pH 5. This method was suitable to remove the chlorotriazine dye (92–93% efficiency), whereas the vinyl sulphone one showed a marked dependence on dye hydrolysis: moderately efficient for the hydrolysed dye and highly efficient without hydrolysis. The activity of laccase was not modified by the usual salinity of the reactive dyeing effluent (20 g/L NaCl). Nevertheless, the effluent salinity enhanced the electrochemical and M. oleifera treatment yield.

Do bifunctional labels solve the problem of dye diffusion in FRET analysis?

We examine the potential application of bifunctional dyes in Förster resonance energy transfer (FRET) experiments due to their increasing popularity in electron paramagnetic resonance spectroscopy. To do this we conduct molecular simulations of the well characterised all-trans polyproline labelled with both mono- and bifunctional rosamine dyes to understand the influence of bifunctionalisation on dye diffusion, orientation and transfer efficiency. As there is a more stiff connection between the labels and the host molecule, the effect of dye diffusion is significantly reduced with bifunctional labels when compared to traditional labels, yielding a narrower FRET efficiency distribution and overcoming a serious hurdle in FRET data analysis. However, the more restricted motion of the bifunctional dyes limits the relative orientation of the dyes, taking the system away from the commonly assumed approximation of isotropic dye orientations. While bifunctional dyes may make it easier to distinguish conformational or biochemical states of the system, they may make it harder to relate transfer efficiencies to distances if the dye orientations are not known.

Synthesis and applications of new bifunctional dyes bis (monochlorotriazine) based on tetrahydrobenzo[b]thiophene moiety

PurposeThe purpose of this paper is to synthesise, characterise and find out properties of some new bifunctional dyes bis (monochlorotriazine) using tetrahydrobenzo[b]thiophene systems as the chromophoric moiety, bearing good colour strength, lightfastness, and other favourable properties.Design/methodology/approachThe novel reactive dyes were prepared, containing bis monochlorotriazine as reactive groups. The dye is synthesised by diazotization and coupling reactions. Firstly the authors synthesised the ethyl 2‐amino 4,5,6,7‐tetrahydrobenzo[b]thiophen‐3‐carboxylate chromophoric moiety compound which in turn underwent diazotization and coupling then diazotized and coupled reaction with either 1‐amino‐8‐naphthol‐3,6‐disulphonic acid (H‐acid) and or 2‐amino‐8‐naphthol‐6‐sulphonic (γ acid) to give the monoazo dye intermediates compounds. The latter products reacted with 2,4,6‐trichloro‐1,3,5‐triazine in 1:1 molar ratio afforded, via nucleophilic displacement when subjected to condensation 2,4,6‐trichloro‐1,3,5‐triazine in 1:1 molar ratio afforded via nucleophilic displacement, which reacted with 1,4‐phenylenediamine in 2:1 molar ratio to give reaction with the 1,4‐phenylenediamine in 2:1 molar ratio, the bisazobifunctional bismonochlorotriazine reactive dyes.bisazo bifunctional bismonochlorotriazine reactive dyes thus yielding the new target reactive. The synthesised dyes were applied onto cotton fabric under the typical exhaust dyeing conditions and their dyeing properties were investigated.FindingsThe results assessed for dyeing indicate high quality dyeing properties However, the homobifunctional (bis MCT) dyes showed higher exhaustion and fixation values, colour yield and fastness properties.Practical implicationsThe described method showed the synthesis of bis monochlorotriazines derived from the tetrahydrobenzo[b]thiophene derivative 3 followed by their application towards cotton fabric.Social implicationsSocial implications are to prepare new reactive dyes having higher fastness and uses for dyeing cotton which is the commonest fabric use.Originality/valueIn this work, the novel reactive dyes derived from the tetrahydrobenzo[b]thiophene derivative 3 were synthesized and their structures were based on the analytical and spectral data. Such a group of compounds are considered to be excellent reactive dyes with different colour shades.

Preparation and use of MitoPY1 for imaging hydrogen peroxide in mitochondria of live cells

Mitochondria peroxy yellow 1 (MitoPY1) is a small-molecule fluorescent probe that selectively tracks to the mitochondria of live biological specimens and responds to local fluxes of hydrogen peroxide (H(2)O(2)) by a turn-on fluorescence enhancement. This bifunctional dye uses a triphenylphosphonium targeting group and a boronate-based molecular switch to selectively respond to H(2)O(2) over competing reactive oxygen species (ROS) within the mitochondria. MitoPY1 can be used to measure mitochondrial H(2)O(2) levels in both cell culture and tissue models. In this protocol, we describe the synthesis of MitoPY1 and how to use this chemical tool to visualize mitochondrial H(2)O(2) in live cells. The preparation of MitoPY1 is anticipated to take 7-10 d, and assays involving microscopy of cultured mammalian cells can be performed in 1-2 d.

Synthesis of pH-Activatable Red Fluorescent BODIPY Dyes with Distinct Functionalities

A series of tunable pH-dependent BODIPY dyes were synthesized and further functionalized in a Knoevenagel condensation reaction with various aldehydes. In this fashion, monofunctional dyes containing an alkyne, azide, or carboxylic acid (masked as its methyl ester) as ligation sites as well as asymmetrical bifunctional dyes were obtained, without compromising their pH-dependency. In addition, fluorescence excitation and emission maxima for these dyes were shown to be significantly red-shifted in comparison to their tetramethyl precursors.