Influence of dispersing agents on adsorption and desorption rate of a disperse dye on polyester (original) (raw)
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Dispersant-free disperse dyes for polyester an eco-friendly approach
The Journal of The Textile Institute, 2016
Disperse dyes contain around 30-60% of dispersing agents as well as dyeing with disperse dyes requires around 2-5 g/L of dispersing agent for faultless dyeing of polyester and other hydrophobic fibres. Dispersing agents are not absorbed by the fibres and a large quantity of dispersing agent creates unavoidable load on the effluent treatment. Dispersant-free disperse dyes seem to have an acceptable solution to this existing problem. These dyes can work in absence of dispersing agents and thus are called as dispersant free disperse dyes. In this work, dispersant-free disperse dyes were synthesised by coupling diazotised p-nitroaniline with the different components like sulfomethylated aniline and m-toluidine. These synthesised dyes were applied successfully on polyester which resulted into uniform dyeing, good build-up and desired colour yield. The dyeing was dependent on the pH and the optimum pH was 5 similar to that employed in conventional polyester dyeing. The fastness properties obtained were good and comparable with the conventional dyes. Whereas the chemical oxygen demand levels of the dispersantfree disperse dyes were much lower than those from commercial disperse dye.
Kinetics of the adsorption of textile disperse dye to modified polyethylene terephthalate
Advanced Technologies
Kinetics of the dyeing process of modified polyethylene terephthalate with disperse dye are shown in this paper. The modification of the fibers was performed with an aqueous solution of slaked lime with the simultaneous action of ultrasonic waves. The dyeing of the fibers was performed in a discontinuous-batch process, with a change in the initial dye concentration (20-120 mg dm-3) and dyeing time (5-60 min). Several kinetic reactions (Pseudo first, Avrami and Modified Freundlich) and diffusion models (Weber&Morris, Boyd, and Film diffusion) were used to test the experimental data from the dyeing process. It has been found that dyeing of modified fibers gives better results than dyeing of unmodified polyester, under the same conditions. With the increase of the initial dye concentration, a degree of exhaustion decreases (76,2-57,4 %, for equilibrium time of dyeing) and the absorption of disperse dyes per unit mass of fibers increases (1,5-6,9 mg g-1 , for equilibrium time of dyeing). During the dyeing process, the initial concentration of the dye decreases, whereas the capacity of the adsorption increases. A linear simulation of the kinetic dyeing parameters showed that the Modified Freundlich reaction model dominated, while of the kinetic diffusion models the Boyd equation was most favorable.
Stability of Dye Dispersions in the Presence of Various Surface Active Agents and Additives
Journal of Dispersion Science and Technology, 2013
Disperse dyes are hardly soluble in water. They are usually milled in the presence of large amounts of dispersing agents in the dye industry. The type and amount of these materials can affect the disperse ability of dyes in aqueous media. In this article, stability of prepared dye dispersions in the presence of various surface active agents and additives were investigated. In this respect, various dispersing agents such as Irgasol DAM, Asutol 644, Dispertane MF, and Irgasol P800 were used to prepare dye dispersions in milling stage. Furthermore, the formulations of dye dispersions were obtained by adding b-cyclodextrin, urea, and wetting agent. The dye dispersion quality was determined by its filtering property, turbidity, and centrifuging method. The obtained results proved the stability of dispersion containing of Irgasol DAM, wetting agent, and b-cyclodextrin as dispersing auxiliaries in dyeing process of disperse dye on polyester fabrics in high temperature method was the highest as compared to other dispersions. From the experimental results, it was found out that stability of prepared dispersions was improved by the presence of b-cyclodextrin. Also, utilization of b-cyclodextrin in formulations of dye dispersions caused to increasing of stability of dispersion in the dyeing of polyester fabrics.
2017
This present work aims to investigate dyeing performance of some new azo disperse dyes belonging to diazotization of 1, 4-bis (2-amino-1, 3, 4-thiadiazolyl) benzene and coupling with different amines as to comparing and contrasting depth obtained of shade and levelness. Some new dyes, such, has been examined, and assessed. The study was concerned mainly with dye uptake, behavior and efficiency. Color measurements, kinetics and thermodynamic parameters were involved. Conventional dyeing, was considered as control for obtained results. © 2017 Elixir All rights reserved. Elixir Appl. Chem. 106 (2017) 46546-46551 Applied Chemistry Available online at www.elixirpublishers.com (Elixir International Journal) Tele: 00201155011735 E-mail address: dr_ali055@yahoo.com © 2017 Elixir All rights reserved M. S. Aboul-Fetouh et al./ Elixir Appl. Chem. 106 (2017) 46546-46551 46547 supplied by Egyptian Turkish Co. (Cairo, Egypt) and 2 g/L of Na2CO3 at 50 °C for 30 min to remove waxes and impurities, ...
Stability of Dye Dispersions in the Presence of Some Eco‐Friendly Dispersing Agents
Journal of Surfactants and Detergents, 2013
The stability of dye dispersions in the presence of ethoxylated sorbitan lauryl and oleyl esters were reported and compared with dye dispersions containing a conventional dispersing agent, i.e. naphthalene sulfonic acid methylene-bis sodium salt (NSAB). The optimum operating conditions obtained using a central composite design and stability of dye dispersions were evaluated by a turbidimetry method. Results showed that the dose of surfactants and the temperature of operation were important factors in preparing stable dye dispersions. Also, the best conditions for preparing dye dispersions were as follows: dose of surfactant 0.05 g, temperature 25°C and time 5 min. In addition to, findings indicated that both of the used surfactants had better performance in dispersing the dyes in water. However, ethoxylated sorbitan oleate had better efficiency relative to other used dispersing agents. The performance of both sorbitan esters were compared with NSAB. The results indicated that they can create stable dye dispersions in aqueous media and have approximately the same effectiveness with NSAB. In this series, although oleate ester had a better performance than the laurate, the difference in performance of using dispersing agents was not significant. This finding was confirmed by the results of the particle size analysis of dye dispersions.
Polyester Dyeing and its Environmental Impact
IOP Conference Series: Materials Science and Engineering, 2020
Dyeing and printing of textiles are responsible for 30% of the pollutants contained in the effluents. The impact of textile dyeing processes on environment is highly variable, most important issues being the colour, the organic charge, and the solids in suspension. The present study investigates the characteristics of the polyester dyeing process in what concerns the environmental issues. Disperse dyes are non ionic, have very limited solubility in water at room temperature and have substantivity for polyester fibre. Two disperse dyes were used, and dyeing were performed at different concentrations. The exhaustion degree, the volume of wastewater used in the process, the specific flow, pH, temperature and chemical oxygen demand of the wastewater, the total residuum, volatile substances and the biological oxygen demand were determined in all the cases. The data obtained showed that the global pollutant content of the wastewater from disperse dyes dyeing is high (more than two times h...
International Journal of Research, 2016
Adsorption kinetics and thermodynamic studies of disperse dyes derived from 4-Amino-3-Nitrobenzaldehyde on polyester fabrics was carried out at various temperatures, pH, liquor ratios, time and carrier concentrations. The results showed the equilibrium adsorption isotherms of disperse dyes on polyester fabrics. The values of the thermodynamic parameters recorded and the adsorption isotherms deduced from the experiment suggests that the adsorption kinetics of the disperse dyes on polyester fabric is in agreement with a pseudo second-order kinetic model [11]. Van der Wa’als forces are thought to have played significant role in dye – fibre attraction and the adsorption of disperse dyes on polyester was an exothermic process. It was found that on application, the dyes had very good fastness to both wash and light and moderate fastness to perspiration.
Adsorption, Kinetics and Thermodynamics of Reactive Dyes on Chitosan Treated Cotton Fabric
Textile & Leather Review
The adsorption performance, kinetics, and thermodynamic parameters of reactive dyes on chitosan-treated cotton fabric are described in this research. The batch experiment was carried out to investigate the influence of pH, time, temperature, dye concentration, and material to liquid ratio of Remazol Red RR and Remazol Yellow RR, two widely used reactive dyes. The adsorption of red and yellow dyes was observed at λmax 517 and 419 nm respectively. For both Remazol Red RR and Remazol Yellow RR reactive dyes with starting dye concentrations of 0.0667 and 40 mg/L, the greatest dye adsorption was reported at pH 11 (0.0009 and 0.1284 mg/g) and pH 4 (0.0004 and 0.1038 mg/g). The adsorption performance was investigated using the Langmuir and Freundlich isotherms. The adsorption behaviours of the two reactive dyes closely matched to the Langmuir adsorption isotherm (R2>0.98) than Freundlich isotherm (R2>0.92). The pseudo-second-order kinetic model (R2>0.99) was followed by the dyeing...
The Canadian Journal of Chemical Engineering, 2014
Experimental data was gathered from more than 700 dyeings of polyester fibres with five naphthalimide disperse dyes. The dyeing process which was the same for all the dyes was carried out separately at five different temperatures, namely: 40°, 60°, 80°, 100°and 120°centigrade. Dye sorption was measured at 10 min time intervals at each temperature until the completion of the dyeing process. Additionally, the raw data was modified by the principal components analysis (PCA) in order to extract the highly informative part of the raw data (i.e. principal components). Such modified data was correlated with the six main sorption models. The results illustrate that unmodified raw data fit a dual combination of sorption models of the Nernst-Freundlich or Nernst-Scatchard type. However, the novel utilisation of PCA-modified data illustrate that a linear Nernst type sorption model is appropriate, making it less dependent on dye structure and aggregation. The validity of this approach was confirmed by sensitivity analysis, affinity calculations and diffusivity determination. Furthermore, a novel 'To To' numerical method worked extremely well in determining diffusion coefficients based on the Hill's approximate solution.