Bifunctional Reactive Dyes Research Articles

Pretreatment and dyeability analysis of cotton and novel Bauhinia vahlii fiber

The textile industry is witnessing a paradigm shift towards sustainable materials, prompting the exploration of novel natural fibers as alternatives to synthetic fibers to meet environmental standards and address the growing demand for eco-friendly and sustainable products. Different natural fibers possess varied properties and are suitable for numerous applications in conventional and technical textiles. The coloration of these textile materials is an important aspect of conventional textiles, which starts with the pretreatment of the material. This study introduces a novel blend of cotton and Bauhinia vahlii fiber, a lesser-known natural cellulosic fiber with promising textile properties, and evaluates its pretreatment outcomes and dyeability characteristics. The study employs a systematic approach to pretreat the cotton and Bauhinia vahlii fiber blend (cotton: Bauhinia vahlii fiber 70:30) in a single bath using a conventional combined scouring bleaching process. The pretreatment process is carried out two times with varied sodium hydroxide (NaOH) and hydrogen peroxide (H2O2) concentrations for different processing times at 90 °C to assess the component fibers’ whiteness index, union bleaching balance, and weight loss percentage under diverse pretreatment conditions. Each time, 50% of the chemicals were used and continued for half of the processing time. The dyeability of the treated fibers is analyzed by dyeing the same in a single bath using amron bright red HF2R bifunctional reactive dye in varied shade depths (1%, 3%, and 5%) and fiber blend ratios (cotton: Bauhinia vahlii fiber 100:0, 90:10, 80:20, 70:30, and 0:100) to assess the color strength, union dyeing balance, and fastness properties. The maximum whiteness was achieved with 6 g per liter (gpl) of NaOH and H2O2 and at a processing time of 150 min with a whiteness index of 80.46 and 54.34 of cotton and Bauhinia vahlii fiber, respectively, with a union bleaching balance of 1.48. The dyed fibers’ colorimetric results confirm that Bauhinia vahlii fiber gives higher color strength than cotton fiber, irrespective of shade depth and blend ratio. The union dyeing balance of 1.2 was achieved at 5% shade depth with a 70:30 cotton Bauhinia vahlii fiber blend. This research contributes to the conventional textile field by introducing a sustainable fiber blend that reduces reliance on synthetic fiber and opens new avenues for utilizing Bauhinia vahlii fiber in conventional textile manufacturing.

Interaction enhancement of Lyocell cellulose chains for controlled fibrillation behavior with greener application in eco-textiles

Lyocell is treated as a biodegradable, sustainable, and low-carbon emission cellulose fiber, but it possesses a high fibrillation tendency in the dyeing process which is generally conducted at alkaline, wet and high-temperature conditions. The fibrillation phenomenon seriously reduces the product quality and affects its application in eco-textiles. In response to the problem, a greener and simple fibrillation prevention treatment was innovatively conducted before the coloration process to enhance the interaction of Lyocell cellulose macromolecular chains. A nonionic crosslinker with isocyanate reactive groups was applied for the fibrillation control. The mechanism of the reaction between the nonionic crosslinker and Lyocell cellulose chains was determined through the measurements of fiber swelling, dynamic surface tension, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). It was found that the fibril interaction was significantly enhanced with reduced lateral swelling of Lyocell fibers. The fibrillation tendency was greatly reduced at the treatment condition of 20 g/L, 175 °C, and 80 s. Moreover, the interaction between cellulose chains was further improved after dyed with bifunctional reactive dyes. In comparison to commercial cationic and anionic crosslinkers, the nonionic sample not only showed little effect on the dye fixation, but also added good wrinkle resistance to Lyocell fabrics. The method showed the advantages of a shorter process and low chemical consumption compared to the conventional Lyocell dyeing process. Therefore, this work may promote the development of Lyocell fabric in high-quality and eco-friendly textiles.

Short wet-steaming low-carbon cleaner pad dyeing of cotton/polyamide/lyocell fabric with reactive dyes

Cotton/polyamide/lyocell three-component fabrics are usually dyed by the traditional dip dyeing technology with two kinds of dyes, which has the disadvantages of long process, high energy consumption and high cost. In this research, the short process cleaner pad dyeing technology for cotton/polyamide/lyocell fabric was developed. The optimal dyeing conditions were that the pH value of initial dye solution was 3–4, the reactive red 195 dye concentration was 10 g/L in the preliminary dye bath, the concentration of NaOH and Na2CO3 were 10 g/L in the alkaline fixing solution, and the steaming time of acid solution and alkali solution was 4 mins. The dyeing effects and fixation rate indicated that short wet-steaming technology was the optimum method. The developed short wet-steaming low-carbon cleaner pad dyeing technology of cotton/polyamide/lyocell fabric not only ensured the color yield, reproducibility, dyeing uniformity and permeability, but also saved dyes and chemicals, shortened dyeing time by 17.4 %, reduced power and heat consumption by 27.1 % and 15.1 %, and decreased carbon emission by 24.6 % compared with traditional dyeing. The K/S values of the dyed samples by short wet-steaming pad dyeing technique indicated that bifunctional reactive dyes with monochlorotriazine and vinyl sulfone sulfate groups (M-type) were superior to the other three kinds of reactive dyes. In the era of low-carbon economy, short wet-steaming low-carbon cleaner pad dyeing of cotton/polyamide/lyocell fabric with reactive dyes is an advanced short process dyeing technology worth of promotion for dyeing a variety of industrial crops and products.

Evaluation of the Stripping Performance of Monochlorotriazine/Vinyl Sulphone Reactive Dyes with a Reductive Stripping Agent

The wet processing industry experiences various problems, such as the faulty and uneven shade of dyeing, colour patch formation on the surface of dyed fabric, etc. during the dyeing and subsequent processing of textile materials. Stripping is considered a process that helps to reuse faulty dyed fabrics by minimizing dyeing faults. The aim of this paper is to evaluate the effectiveness of stripping agents and the quality of stripped cotton knit fabrics that were coloured using bi-functional (monochlorotriazine/vinyl sulphone) reactive dyes. First, the trichromatic combination of Drimarene Yellow CL2R, Drimarene Red CL5B and Drimarene Blue HFRL dyes was used to dye fabrics in two different shade percentages, namely light shade (0.3% owf) and dark shade (3.0% owf). Consequently, stripping was carried out using varying concentrations of stripping chemicals (hydrose (Na2S2O4) and caustic soda (NaOH)) and process temperatures. Stripped fabrics were assessed after measuring the weight loss percentage, strength loss percentage, whiteness index and stripping efficiency. The results of that assessment showed a relatively better stripping performance with the chemical concentration of 5 g/L hydrose and 5 g/L caustic soda at 100 °C. Under this condition, the value of the whiteness index and stripping efficiency were adequate, with a minimum weight loss percentage and strength loss percentage. The stripping performance for the light shade (0.3% owf) fabric was deemed to be better than that for the dark shade (3.0% owf) fabric.

Study of the Influence of the Surface Roughness of Knitted Fabrics from Natural Fibres on the Light Fastness of Their Colours

The article examines the influence of the surface properties of knitted fabrics from cotton and wool of various knitted structures on the light fastness of their colours. The surface properties of knitted fabrics of single plain, 1×1 rib and French piqué knitted structures were evaluated by determining their roughness using a non-contact optical method for processing digital images of the knitted fabric’s surface. The roughness profiles of the corresponding knitted fabric samples were obtained, and the main indicators of surface roughness were calculated: the profile height at ten points Rz and the arithmetic mean profile deviation Ra . Cotton knitted fabrics were dyed with the Bezaktiv Cosmos dye brand, which are bifunctional reactive dyes with monochlorotriazine / vinyl sulfone active groups, and wool knitted fabrics were dyed with acid dyes. The light fastness of the samples was evaluated after exposure to the Light Fastness Tester (Mercury-Tungsten Lamp) RF 1201 BS (REFOND) with a PCE-TCR 200 colorimeter. Colour measurements were averaged for each sample. Total colour difference (dE) was measured on the dyed cotton knitted fabrics samples after light exposure. According to the obtained roughness profiles of cotton and wool knitted fabrics, it can be concluded that the studied knitted fabrics are characterized by different roughness, which depends on their knitted structures. At the same time, a relationship was found between an increase in the roughness of knitted fabrics and the photodestruction of colours by reactive and acid dyes on cotton and wool knitted fabrics, respectively. The results show that the surface structure of knitted fabrics, that is the knitted structure, impacts the process of colour photodestruction and that the amount of dye that has undergone photodestruction increases with the increasing surface roughness of the knitted fabric.

Photophysical Properties of a Novel Xanthene Dye

Reactive dyes with fluorescent properties are among the most demanded. However, these dyes have a limit in hues since there is no full range of these dyes in the commercial. Therefore, in this research, we presented a xanthene-based bi-functional reactive dye with the fluorescent property. In this regard, the first 2,4,6-trichloro-1,3,5-triazine was reacted with 1-amino-2-methoxy-4-beta-hydroxy ethyl sulphone sulfate ester, and then the obtained product was reacted with 2-(6-hydroxy-3-oxo-3H-xanthene-9-yl). The dye characteristics were studied by TLC, 1HNMR, 13CNMR, FTIR, elemental analysis, UV-Vis spectrophotometer, and spectrofluorimeter techniques. The photophysical properties of a synthesized dye, such as absorption and emission wavelength maxima, quantum yield, stokes shift, and energy yield, were measured. The effect of polarity of solvents on the photophysical properties of synthesized dye was explored using four polar and nonpolar solvents (water, DMF, methanol and acetone). The results indicated that the synthesized dye showed a positive solvatochromism effect. The absorption and emission wavelengths were 465-490 nm 498-538 nm, respectively. The quantum yield of synthesized dye was in a range of 0.04-0.66 in different solvents.

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 antibacterial activity of some novel nucleus N-aminorhodanine based bis monofunctional and bifunctional reactive dyes and their application on wool and cotton fabrics

Hiren, we aimed to synthesis two new reactive dyes based on derivatives of Aminorodanine as a chromoforic group, as well as to apply the dye and antibacterial activity to the dyed fabric. First, we synthesized 3-amino rhodanine with glutaraldehyde and terephalaldhyde (2: 1 mole) to form compounds A & B respectively. After that we prepared monofunctional monochlorotriazine (MCT) and bifunctional monochlorotiazine sulphatoethyl sulphone (MCT/SES) by first condensation m- phenylene diamine sulphonic acid with Cyanuric chloride (1:1 mole) in ice bath then the second condensation takes place with sulfanilic acid or 1-Aminobenzene-4-β-sulfatoethylsulfone (PABSES) (1:1 mole) at room temperature; the pH was maintained at 5-6 by simultaneous addition 2 M sodium carbonate solution to form monofunctional reactive group C and bifunctional reactive group D respectively. Finally, we synthesized dyes by diazotized C and D by adding sodium nitrite (0.01 mol) to appropriate amines (0.01 mole) in concentrated HCl (6 ml) at (0-5 oC) under stirring then coupling with compounds A and B after dissolved them in ethanol with 2 M of sodium carbonate by 2 mol of the diazonium salt with 1 mole of coupler. The reactive dyes bis MCT 1, 2 and Bis MCT/SES 3, 4 are formed. We provided synthesized dyes structures by elemental analysis, IR, and 1HNMR spectroscopy. These dyes are used in dyeing cotton and wool that show good light fastness, and are excellent for washing, rubbing, and sweating fastness. Also, we measure antibacterial activity for cotton and wool fabrics toward Gram-negative and Gram-positive

Dyeing and printing study of synthesized reactive dyes using phenyl urea bifunctional reactive dyes on cotton fabric

Reactive dyes have verity of Shades and have a good all fastnesses properties. Bifunctional reactive dyes were mostly popular in Dyeing and Printing industries. Three Bifunctional reactive dyes was synthesized and this dyes applied on Cotton fabric with Dyeing and Printing Method. Cold Pad-Batch and Exhaust dyeing method was used for application of Dyeing… Dyes were characterized by absorbance spectra, IR and 1H NMR. The main object of study was to get maximum strength as well as good fastness properties of Synthesized dyes on Cotton fabrics. Different parameters for Dyeing like Time of Dyeing, pH of Dye bath and Concentration of Alkali were study. From the study it was observed that All dyes gave good fixation on 100%cotton fabric and also gave good absorbance above 60% results with printing method. The all dyes have good fixation on cotton by Cold Pad-Batch dyeing method Synthesized Bifunctional reactive dyes had excellent fastness properties.

A greener approach to cotton pre-treatment using bentonite clay

Cotton dyeing and printing requires a number of preparatory processes involved the use of various chemicals and eventually creates massive pollution load on effluent which disposed in the environment directly or partially treated consequently increases the health hazard. In this work cotton knitted fabric was scoured and bleached by naturally occurring clay ‘Bentonite’ as an alternative of auxiliaries. The wetting power, detergency, sequestering power and stabilizing action of bentonite clay was tested thoroughly. The scouring and bleaching efficiency and dyeability with a bi-functional reactive dye were evaluated on differently pretreated samples. The residual pretreated liquors were analyzed for ecological parameters including pH, Total dissolved solids, chemical oxygen demand, and biological oxygen demand (BOD5). In comparison with conventional auxiliaries, bentonite clay showed acceptable results. The scouring and bleaching performances of all pretreated fabrics was satisfactory. All samples were evenly dyed and there was no noticeable color difference. It also observed that bentonite clay treated liquors create less pollution when compared to the conventional treated liquors. Finally, cost of bentonite process was calculated and compared with conventional.

Sustainable dyeing of cotton fabric with reactive dye in silicone oil emulsion for improving dye uptake and reducing wastewater

From sustainable chemistry and engineering perspectives, water and energy consumption are arguably the main issues in the textile industry. Thus, a silicone reverse emulsion dyeing system is developed to dye cellulosic textile with reactive dye. When the amount of dye is the same, the color depth of dyed cotton fiber is 13.82 and the fixation of dye is 87.76% in the silicone reverse emulsion dyeing system. In traditional water-based dyeing system, the color depth of dyed cotton fiber and the fixation of dye is only 9.31, 56.63% respectively. The silicone reverse emulsion dyeing technology does not consumes salts, but it can improve the dye fixation by 31.13%, and decreases the dye discharge by 72.41%. For the hydrolysis of bifunctional reactive dye, the main hydrolysis reaction is the individual hydrolysis of monochlorotriazine or vinyl sulfone at the prophase of hydrolysis. After 30 min, the additional β-hydroxyethyl sulfone and hydroxyl triazine dye are hydrolyzed to dihydroxyl dye. To confirm the hydrolytic reaction energy of dye in different dyeing system, the optimization of molecular structure, the hydrolysis reaction gap and the distribution of electron density on the dye were investigated using density functional theory. The hydrolytic reaction energy gap of bifunctional reactive dye is higher in silicone reverse emulsion dyeing system than that in traditional aqueous dyeing system, resulting the hydrolysis of dye is difficult in silicone oil emulsion dyeing system. The electron density is distributed almost entirely on the carbon–carbon double bond and triazine group in the HOMO of the dye, resulting in the LUMO of dyes can attacked by HOMO of hydroxyl anion. These successful investigations of the dyeing performance and the hydrolysis mechanism of dye explain that reactive dye can keep a long reactivity to fiber and effectively reduce the number of washing times, which greatly reduces the discharge of dyeing waste water.

Synthesis of reactive dyes by the introduction of Phenyl Urea derivatives into the triazine ring and their application on different fibers

Reactive dyes are most popular class of dyeing for cotton. Currently bifunctional reactive dyes is mostly used in textiles industries. Bifunctional reactive dyes have good fastness properties, wide colour gamut, flexible application procedure. Novel bifunctional reactive dyes synthesized into the triazine ring by introducing Phenyl Urea and its derivatives. Derivatives of Phenyl Urea and (j-acid) 2-amino-5-naphthol-7-sulphonic acid were condensed with 2, 4, 6-Trichloro-1, 3, 5-triazin synthesized coupling component.4-(β-sulfatoethysulfonyl) anilin was used as a diazo component. IR spectroscopy, Visible absorption spectra and 1H NMR were used for characterization. All dyes has been examined on silk, wool and cotton. Fastness properties and exhaustion and fixation value of all synthesized dyes were evaluated. In this study it was observed that all synthesis dyes showed high exhaustion and fixation, good Wash fastness to colour, good migration and leveling dyeing.

A Three-Bath Process for Dyeing Cotton with Bis-Azo Bi-Functional Reactive Dyes Based on Diazonium Salts

Mono-azo dyes possessing a primary aromatic amino group have been shown to react with cotton by diazotization followed by treatment with soda ash at 60–65 °C thereby acting as monofunctional reactive dyes. Bis-azo dyes bearing two amino groups are expected to act as bi-functional reactive dyes and exhibit enhanced dye-cellulose fixation. This work shows that the difference in fixation exhibited by mono-azo and bis-azo dyes is statistically significant at 95 % confidence level in favor of the latter group. This work describes a three-bath dyeing process which reduced the amount of consumed water by 60.6 % and the environment factor by 62.2 %. The newly developed three-bath process also conserves energy by 74.1 %. Hence, a new class of bifunctional reactive dyes without externally attached reactive systems is, in principle, available. It will have the advantage of reducing raw materials and manufacturing costs. It also employs a sustainable reactive dyeing process.

Decolorization of Reactive Yellow 174 dye in real textile wastewater by active consortium: experimental factorial design for bioremediation process optimization

Dyes are priority pollutants, commonly found at significant concentrations in textile effluents. The presence of dye stuffs in wastewater can cause severe problems to aquatic life and human beings. Therefore, the removal of dyes from wastewater is important in order to minimize their hazardous effects on the environment. The best microbial species for such an application was selected amongst the isolated bacterial populations by conducting cold bifunctional reactive dye namely CI Reactive Yellow 174 (CI RY 174) batch degradation studies using bacterial strains. The most suitable species were Sphingomonas paucimobilis, Pseudomonas putida and Lactobacillus acidophilus. Process parameters were optimized using response surface methodology (RSM) and under the optimum conditions (e.g. inoculum size of 10% (OD600nm = 1), temperature of 35 °C, 150 ppm, and time of 5 days). The maximum COD and color removal efficiencies, when tested with 750 ppm dye using batch reactors were found to be 86% and 90%, respectively. Our results showed that bacteria had a high decolorization capacity. High regression coefficient values (predicted R 2 = 83.65%) confirmed that the predicted values were in compliance with the experimental values implying the appropriateness of the employed regression model. The adequacy of the model was validated by different descriptive statistics viz, regression, residual error, F and p values. UV–visible and FTIR spectroscopy analysis confirmed the biodegradation of CI RY 174. Using phytotoxicity endpoints, toxicological studies of CIRY 174 before and after biodegradation were studied. Toxicity assay proved that biodegradation led to detoxification of CIRY 174 dye.

Application of Multifunctional Reactive Dyes on the Cotton Fabric and Conditions Optimization by Response Surface Methodology

ABSTRACT This study presents optimization of dyeing variables for dyeing 100% cotton fabric with two novel bifunctional reactive dyes D-1 and D-2. These dyes have sulfatovinylsulfone and monochlorotriazine functional moieties. The impact of different variables, including dyeing temperature, salt concentration, and alkali, was investigated and optimized using response surface methodology (RSM). In spite of an exploring structural difference between both of these dyes, the dyeing temperature was optimized at the same value (61.68°C). The optimized conditions of salt (43.33 g/L) and alkali (29.50 g/L) for D-1 were resulted in 72.29% (±3) of exhaustion and 67.45% (±3) fixation. Similarly, D-2 showed 69% (±3) of exhaustion and 62.5% (±3) fixation at optimum value of salt (44.05 g/L) and alkali (33.87 g/L) concentration. Results showed better fixation and exhaustion of D-1 than dye D-2 which may be attributed to its more structural planarity and lower steric hindrance. The different fastness behaviors of dyes were found good to excellent for both dyes. The results attained were useful and suitable for commercial dyeing processes.

Study of C.I. Reactive Yellow 145, C.I. Reactive Red 238 and C.I. Reactive Blue 235 dyestuffs in order to use them in color formulation. Part 2: modeling and optimization of dyeing performances

This article models and optimizes the effect of dyeing parameters on obtained color of fabric samples dyed with three cold bifunctional reactive dyes, namely, C.I. Reactive Yellow 145, C.I. Reactive Red 238 and C.I. Reactive Blue 235, in order to use them in color formulation. The studied dyeing parameters are electrolyte concentration, alkali concentration, liquor-to-fiber ratio and temperature of dyeing process. The influence of these parameters was analyzed for four different shades: 0.1%, 1%, 2% and 4%. Two criteria of evaluation are studied and optimized: the exhaustion and the fixation yields. Linear modeling of optimal concentrations of electrolyte and alkali according to the dye concentration was developed, allowing the calculation of optimal quantities which should be added to the dye bath for any dye concentration. Color coordinates and fastness (washing, rubbing and light fastness) of samples dyed with optimal conditions are also evaluated and discussed.

Synthesis and application of KM‐type reactive dyes containing 2‐ethoxy‐4‐chloro‐s‐triazine

AbstractA new kind of hetero‐bifunctional reactive dye containing 2‐ethoxy‐4‐chloro‐s‐triazine, with better activity matching with β‐hydroxyethyl sulphone sulphate at a low fixation temperature, was successfully synthesised and characterised. An ethoxy group was designed to be introduced into triazine to increase the substantivity and the reactivity of the dyes. Thereby, the fixation of mono‐s‐chlorotriazine/hydroxyethyl sulphone sulphate (KM‐type) bifunctional reactive dyes on cotton was improved, and dyeing under mild conditions with high fixation was realised. Nineteen dyes with orange, red and blue colours were synthesised and characterised by UV‐Vis and infrared spectroscopy and mass spectrometry. Synthesised dyes were dyed at 60, 75 and 90°C, respectively. Exhaustion and reactivity for all of the ethoxy‐containing KM‐type dyes was over 90% at the optimal temperature, and fixation was over 87%, which was higher than the ethoxy‐free comparative dyes. The optimal fixation temperature of ethoxy‐containing dyes was initially reduced to 75°C, and then to 60°C. Compared with comparative dyes, the wash fastness and light fastness were basically unchanged, and the wet rub fastness of the H‐acid series was reduced by one grade.

Dyeability, Kinetics and Physico-Chemical Aspects of Bombyx Mori Muslin Silk Fabric with Bi-Functional Reactive Dyes

ABSTRACT Bombyx mori muslin silk fabric was dyed with three different bi-functional reactive dyes in exhaust method. Dyeability of the silk fabric was analyzed by reflectance spectra, microscopic appearance, color strength, and saturation limit. Thermal influence on dye exhaustion, migration index, level dyeing factor, and color fastness properties were also investigated. Different kinetic models were approached to study dynamic behavior of dye adsorption and predictability of the models was assessed by co-efficient of regression (r2), root mean square error (RMSE), and mean absolute error (MAE). Some physico-chemical parameters such as activation energy and chemical potential of dyeing were also evaluated. Brilliant color was observed on silk by all class of reactive dyes. A controlled dyeing condition was also suggested to avoid the risk of unlevel dyeing. Wet fastness properties exhibited excellent results on silk fabric. The adsorption data conformed to the pseudo second-order kinetic model with r 2 ≥ 0.94 and the activation energy (ΔE) valued (≥55 kJ/mol) within the range of chemisorption for all dyes. The increase of negativity of chemical potential supported higher dye uptake on silk at elevated temperature.

Bifunctional reactive pentamethine cyanine dyes for biomedical applications

New unsymmetrical pentamethine cyanine dyes containing two non-equivalent reactive groups selected from carboxyl, amino and hydroxyl in different combinations were synthesized and their spectral properties investigated. Amino and hydroxy groups were used for binding the dyes to the anticancer drug, chlorambucil (CLB) via biodegradable amide or ester linker while the second reactive functionality could be utilized for attachment at mild conditions to a targeting carrier such as an antibody or peptide. These conjugates can thereby potentially be suitable for fluorescence-based monitoring of drug delivery. The CLB release profiles triggered by biodegradable linker were investigated in buffer solutions and cell medium using LC-MS and spectrofluorimetric methods.

Application of MCT-βCD to Modify Cellulose/Wool Blended Fabrics for Upgrading Their Reactive Printability and Antibacterial Functionality

Pre-loading of monochlorotriazinyl β-Cyclodextrin (MCT-βCD) onto/within viscose/wool (V/W) and cotton/wool (C/W) blended fabrics provide hosting cavities that can form host-guest inclusion complexes with reactive dyes in postprinting as well as with triclosan derivative or silver nanoparticles/hyperbranched polyamide-amine (AgNPs/HBPAA) composite in subsequent final antibacterial finishing step. Coloration properties, antibacterial activity against (S. aureus) and (E. coli) pathogenic bacteria, durability of the obtained products, according to the above mentioned route, to wash, surface morphology and composition of selected samples were investigated. Results obtained signify that premodification of the nominated substrates with MCT-βCD (10 g/l), followed by reactive printing with mono-or bifunctional reactive dye (20 g/l), and subsequent post-finishing with triclosan derivative or AgNPs/HBPAA composite (15 g/l each) is an efficient treatments sequence for attaining reactive prints with significant antibacterial efficacy and noticeable durability to wash. Surface depositions of selected active ingredients were also confirmed using SEM and EDX analysis.