Supercritical Carbon Dioxide Dyeing Research Articles

Solubility of an acid dye in supercritical carbon dioxide by ion-pairing with dodecyltrimethylammonium bromide

In this study, solubility of Acid Red 57 (AR57), which is an anionic dye, in supercritical CO 2 was investigated using an ion-pairing with dodecyltrimethylammonium (DTMA) bromide. The measurements of AR57 and AR57-DTMA in supercritical CO 2 without/with methanol as a modifier solvent were carried out at temperatures from 45 to 100 °C and pressures from 250 to 325 bar. Although AR57 is insoluble in supercritical CO 2 even with methanol as a modifier solvent, AR57-DTMA can dissolve in methanol modified supercritical CO 2. The hydrophobic ion-pairing provides a possibility for the solubility of hydrophilic dye in supercritical CO 2. The solubilities of AR57-DTMA were measured in methanol modified supercritical CO 2 and the results were correlated by using a semi-empirical equation.

Correlation of dye solubility in supercritical carbon dioxide

A new methodology proposed here correlates the dye solubility in supercritical CO 2. This methodology uses the expanded liquid model, which the solid–fluid equilibrium is modeled using the Margules model. The regressed parameter ( A 21) of Margules model is calculated using an empiric equation that relates A 21 with the temperature and pressure of the system. The experimental dye solubility of CI disperse red 60, CI disperse orange 3, CI disperse blue 3, and CI disperse blue 79 in supercritical carbon dioxide [J.W. Lee, J.M. Min, H.K. Bae, Solubility measurement of disperse dyes in supercritical carbon dioxide, J. Chem. Eng. Data 44 (1999) 684–687; J.W. Lee, M.W. Park, H.K. Bae, Measurement and correlation of dye solubility in supercritical carbon dioxide, Fluid Phase Equilibr. 173 (2000) 277–284] at temperatures from 323.7 to 413.7 K and pressures from 100 to 300 bar were used for evaluating this new methodology. The results obtained using the proposed technique showed good agreement with the experimental data used.

Acid-catalysed methanolysis reaction of non-polar triazinyl reactive dyes in supercritical carbon dioxide

An extensive study of the reaction mechanism of the methanolysis reaction of triazinyl systems of non-polar reactive dyes has been done in a neutral, moderately acidic and strongly acidic medium. In a neutral reaction medium, dichlorotriazines are more reactive than the monochlorotriazines. However, in a moderately acidic medium, as supercritical carbon dioxide, an inversion in the reactivity pattern of monochlorotriazines was observed, which is related to the dye structure. Amines as substituent group attached to the triazinyl ring showed the largest conversion and k values, approaching those values of dichlorotriazine. Protonation of the ring, and stabilization of the positive charge in the triazinyl ring due to the mesomeric effect, explain the reactivity increased of monochlorotriazines. When acids were added to the reaction medium, resulting in an increase of the acid concentration, the reactivity of monochlorotriazinyl dyes was surprisingly much larger than dichlorotriazine; k values increased up to a factor of 54. The largest k was measured for the monochlorotriazinyl dye, S1Cl–NH 2, showing a value of 3.0 × 10 −3 s −1, while a value of 3.2 × 10 −4 s −1 was measured in supercritical carbon dioxide. In a strongly acidic medium, the reactivity of triazinyl reactive dyes is substantially influenced by the basicity of the substituted groups in the reactive group, and in the chromophore. Based on this kinetic study, the dyeing of cotton in supercritical carbon dioxide under acidic conditions seems to be very promising when triazinyl dyes are used.

Solubility of disperse dyes in supercritical carbon dioxide and ethanol

The aim of this work is the investigation of the solubility of three disperse dyes in a mixture of CO 2 and ethanol. Experimental solubilities of disperse blue 79, disperse orange 3 and solvent brown 1 in a mixture containing 5.5 mol% of ethanol in carbon dioxide have been measured using a dynamic apparatus and compared with those in pure carbon dioxide [A. Ferri, M. Banchero, L. Manna, S. Sicardi, J. Supercrit. Fluids 30 (2004) 41–49]. The effect of the co-solvent is so pronounced that solubilities similar to those measured in pure carbon dioxide have been achieved in the mixture at pressures 100 bar lower. The experimental results have been correlated with three different approaches: the Peng–Robinson equation of state [D.Y. Peng, D.B. Robinson, Ind. Eng. Chem. Fundam. 15 (1976) 59–63], the semi-empirical Chrastil equation modified for ternary systems [J.C. Gonzales, M.R. Vieytes, A.M. Botana, J.M. Vieites, L.M. Botana, J. Chromatogr. A 910 (2001) 119–125] and, finally, a correlation recently proposed by our research group for binary systems [A. Ferri, M. Banchero, L. Manna, S. Sicardi, J. Supercrit. Fluids 32 (2004) 27–35] here applied for the first time to ternary systems. The results have pointed out that the third semi-empirical equation gives the best agreement between the experimental and calculated solubilities.

Solubility prediction of 21 azo dyes in supercritical carbon dioxide using wavelet neural network

The solubility of 21 azo dyes in supercritical carbon dioxide was related to the six descriptors over a wide range of pressures (100–355 bar) and temperatures (308–413 K). The wavelet neural network (WNN) model was constructed with six descriptors as an input layer, eight neurons as a hidden layer and a neuron as an output layer. The descriptors consisted of temperature, pressure, LUMO energy, polarizability, volume of the molecule and number of unsaturated bonds and they were selected based on stepwise feature selection from different descriptors using multiple linear regression (MLR) method. The WNN architecture and its parameters were optimized simultaneously. The data were randomly divided into the training, prediction and validation sets. The RMSE and mean absolute errors in WNN model were 0.220 and 0.158 for prediction set and 0.156 and 0.114 for validation set. In addition, the prediction ability of the model was also evaluated for five azo dyes, the molecules and data of which were not in any previous data sets. The performance of the WNN model was also compared with artificial neural network (ANN) and MLR models.

Solubility Measurement and Dyeing Performance Evaluation of Aramid NOMEX Yarn by Dispersed Dyes in Supercritical Carbon Dioxide

The solubility of various dispersed dyes in supercritical carbon dioxide was measured and, subsequently, based on the solubility data, the dry dyeing was conducted in a temperature range of 363.15−423.15 K and at pressures of 10−30 MPa. The target fibers are Aramid NOMEX yarn obtained from Du Pont, which is known to be difficult to use to perform wet dyeing, and the dispersed dyes include E-types of C. I. Dis Red 60, Blue 56, and Yellow 54 and S-types of C. I. Dis Red 360, Blue 79, and Yellow 114. Solubility data of the dispersed dyes in CO2 were correlated in terms of the density of carbon dioxide, using an empirical equation of Bartle et al. The highest color depth (K/S) of the dyed Aramid spun yarn was obtained when the experiment was performed at 423.15 K and 30 MPa. The adsorption isotherms were measured using the concentration of the three dyestuffs (E-types). These adsorption isotherms follow the Langmuir type. As a result of the supercritical fluid dyeing (SFD) for Aramid yarn with the three diffe...

Wavelet neural network modeling in QSPR for prediction of solubility of 25 anthraquinone dyes at different temperatures and pressures in supercritical carbon dioxide

A wavelet neural network (WNN) model in quantitative structure property relationship (QSPR) was developed for predicting solubility of 25 anthraquinone dyes in supercritical carbon dioxide over a wide range of pressures (70–770 bar) and temperatures (291–423 K). A large number of descriptors were calculated with Dragon software and a subset of calculated descriptors was selected from 18 classes of Dragon descriptors with a stepwise multiple linear regression (MLR) as a feature selection technique. Six calculated and two experimental descriptors, pressure and temperature, were selected as the most feasible descriptors. The selected descriptors were used as input nodes in a wavelet neural network (WNN) model. The wavelet neural network architecture and its parameters were optimized simultaneously. The data was randomly divided to the training, prediction and validation sets. The predictive ability of the model was evaluated using validation data set. The root mean squares error (RMSE) and mean absolute errors were 0.339 and 0.221, respectively, for the validation data set. The performance of the WNN model was also compared with artificial neural network (ANN) model and the results showed the superiority of the WNN over ANN model.

Solubility of a spiroindolinonaphthoxazine photochromic dye in supercritical carbon dioxide: Experimental determination and correlation

The measurement and correlation of the experimental solubility of a spiroindolinonaphthoxazine photochromic dye (1,3-dihydro-3,3-dimethyl-1-isopropyl-6′-(2,3)-(dihydroindole-1-yl)spiro[2 H-indole-2,3′-3 H-naphtho[2,1- b] [1,4] oxazine]) in supercritical carbon dioxide (scCO 2) is reported. Results were obtained using a static analytical method, at 308.0, 318.0 and 328.0 K, and in a pressure range from 10.0 to 26.0 MPa. Solubility experimental data were correlated with three density-based models (Chrastil, Bartle and Méndez-Santiago–Teja models), with the Ziger–Eckert semi-empirical correlation and with two cubic equation-of-state (EOS) models, namely the Peng–Robinson EOS (PR-EOS) and the Soave–Redlich–Kwong EOS (SRK-EOS), together with the conventional van der Waals mixing and combining rules. Good correlation results were obtained between the calculated and experimental solubility, to all fitted models. Solubility results clearly indicate the feasibility of processing this dye, and possibly this class of photochromic dyes, using supercritical fluid technologies and processes, for example, supercritical fluid dye impregnation of polymer host materials.

Dye uptake and partition ratio of disperse dyes between a PET yarn and supercritical carbon dioxide

The equilibrium uptake of three disperse azoic dyes in a commercial PET yarn in presence of supercritical carbon dioxide was measured. The dye uptake was found to be much more sensitive to temperature than to pressure in the tested operative conditions. The equilibrium partition coefficient between the fibre and the supercritical fluid was evaluated from previously measured solubility data [A. Ferri, M. Banchero, L. Manna, S. Sicardi, An experimental technique for measuring high solubilities of dyes in supercritical carbon dioxide, J. Supercrit. Fluids 30 (2004) 41; A. Ferri, M. Banchero, L. Manna, S. Sicardi, A new correlation of solubilities of azoic compounds and anthraquinone derivatives in supercritical carbon dioxide, J. Supercrit. Fluids 32 (2004) 27]. The high values of the partition coefficients demonstrated that the partition of the dye between the fluid and the polymer is an important parameter to evaluate the feasibility of the dyeing process in supercritical carbon dioxide. The partition coefficients were correlated with three equations: an equation proposed by Funazukuri et al. with four fitting parameters [Ind. Eng. Chem. Res. 41 (2002) 2812]; a semi-empirical equation, with five fitting parameters, that was developed assuming a Langmuir-type absorption of the dyes into the yarn; and an empirical equation, with three fitting parameters, developed from simple experimental data observation. The best agreement was obtained with the second, semi-empirical equation. Good results were also obtained with the third, empirical equation and the agreement with experimental data was better than that obtained with the equation proposed by Funazukuri et al. even though it makes use of one fitting parameter less.

Measurement and correlation of solubility of Acid Red 57 in supercritical carbon dioxide by ion-pairing with hexadecyltrimethylammonium bromide

Solubility of C.I. Acid Red 57 (AR57) in supercritical carbon dioxide was measured by ion-pairing with hexadecyltrimethylammonium (HDTMA) bromide. The solubility measurements of AR57 and AR57-HDTMA in supercritical carbon dioxide without/with methanol as a modifier solvent were carried out at the temperature range from 35 to 75 °C and for pressures from 250 to 325 bar. The solubility of AR57 and AR57-HDTMA was examined in terms of pressure and temperature of supercritical carbon dioxide. Even though Acid Red 57 is insoluble both in supercritical carbon dioxide and methanol-modified supercritical carbon dioxide, AR57-HDTMA can easily dissolve in methanol-modified supercritical carbon dioxide. The hydrophobic ion-pairing of HDTMA provides a possibility to dissolve a hydrophilic dye in supercritical carbon dioxide. A semi-empirical equation was used to correlate the obtained experimental solubilities of AR57-HDTMA by means of the density of carbon dioxide in methanol-modified supercritical carbon dioxide.

Effects of pressure and temperature on dyeing acrylic fibres with basic dyes in supercritical carbon dioxide

The dyeing of acrylic fibre with CI Basic Blue 47 has been investigated using an ammonium carboxylate perfluoropolyether as an auxiliary in order to perform the reverse micellar system in supercritical carbon dioxide media. The basic dye was satisfactorily solubilised in the interior of the reverse micelle in the system, and dyeability in the supercritical carbon dioxide media was excellent, even in the absence of a retardant and/or an acid. The optimum proton-rich condition for dyeing of acrylic fabric is performed in reverse micelle aggregates and the proton-rich water pool is suitable for dye uptake by the fibre even without the presence of additives. Changes in glass transition temperature of acrylic fibre in the carbon dioxide media also influence the dyeing behaviour of acrylic fabric.

Investigations on the solubilities of some disperse azo dyes in supercritical carbon dioxide

The solubilities of three disperse azo dyes, 4-(N,N-dimethylamino)-4′-nitroazobenzene (D1), 4-(N,N-diethylamino)-4′-nitroazobenzene (D2) and Parared (D3) in supercritical carbon dioxide have been measured at different temperatures (308, 318, 328, 338, 348 and 358 K) and in the pressure range of 122–355 bar. The measurements were performed using a simple static method. As evidenced from the experimental results, the solubilities increase with increasing density of supercritical CO2. The solubilities in supercritical CO2 decrease in the order D2>D1>D3, which parallel the order of their relative melting points; the higher the melting point, the lower the solubility. The equilibrium solubility data were correlated using a semiempirical model. The calculated results show satisfactory agreement with the experimental data.

One-Bath Dyeing of Polyester/Cotton Blends with Reactive Disperse Dyes in Supercritical Carbon Dioxide

One-bath dyeing of polyester/cotton blends with reactive disperse dyes is investigated using supercritical carbon dioxide (SC-CO2) as a solvent in the range of 353 to 393 K and 10 to 20 MPa. One-bath dyeing of polyester/cotton blends is successful. The dyeing behavior is compared with the thermosol dyeing method using the same dye. Samples are subjected to a color fastness test and colorimetric measurements. Good color intensity and wash fastness are obtained by the SC-CO2 dyeing method at 393 K and 20 MPa. The color fastness properties of fabrics dyed in SC-CO2 are superior to those of fabrics dyed by the thermosol dyeing method.

Kinetics study of a dichlorotriazine reactive dye in supercritical carbon dioxide

The kinetics of the reaction between a dichlorotriazine reactive dye and methanol was studied in supercritical carbon dioxide and in a solution of pure methanol. The experiments were carried out in a batch reactor at different temperatures between 333 and 393 K and at 300 bar when supercritical carbon dioxide was the solvent medium. The rate constants and the parameters of the Arrhenius equation were determined and compared. A significant influence of the supercritical carbon dioxide on the rate constants was found. The formation of methoxy-dye was faster over the whole temperature range in pure methanol than in supercritical carbon dioxide. But the consecutive reaction, the formation of dimethoxy-dye, was considerably faster, up to 20 times, in supercritical carbon dioxide than in pure methanol. Moreover, the lowest value for the activation energy, 50 ± 13 kJ mol −1, was found for the consecutive reaction in supercritical carbon dioxide. In this paper new kinetic data for the methanolysis reaction of a dichlorotriazine reactive dye in supercritical carbon dioxide are shown.

Investigations on the solubilities of some disperse azo dyes in supercritical carbon dioxide

The solubilities of three disperse azo dyes, 4-( N, N-dimethylamino)-4′-nitroazobenzene (D 1), 4-( N, N-diethylamino)-4′-nitroazobenzene (D 2) and Parared (D 3) in supercritical carbon dioxide have been measured at different temperatures (308, 318, 328, 338, 348 and 358 K) and in the pressure range of 122–355 bar. The measurements were performed using a simple static method. As evidenced from the experimental results, the solubilities increase with increasing density of supercritical CO 2. The solubilities in supercritical CO 2 decrease in the order D 2>D 1>D 3, which parallel the order of their relative melting points; the higher the melting point, the lower the solubility. The equilibrium solubility data were correlated using a semiempirical model. The calculated results show satisfactory agreement with the experimental data.

Effect of supercritical carbon dioxide dyeing conditions on the chemical and morphological changes of poly(ethylene terephthalate) fibers

AbstractCommercially available regular denier poly(ethylene terephthalate) (PET) fabrics were used in this investigation. PET fabric samples were wound on a bobbin and then exposed to supercritical CO2 under conditions representing a typical supercritical CO2 dyeing cycle. Infrared spectroscopy, X‐ray diffraction, differential scanning calorimetry, and scanning electron microscopy were used to characterize the chemical and morphological changes of the PET fibers. The results showed that exposure to supercritical CO2 did not cause chemical changes in the fibers; the crystal size and the Tmp of the PET fabric after treatment in supercritical CO2 did not significantly change; the crystallinity decreased; and the treatment in supercritical CO2 at higher temperature caused surface morphology changes (increased oligomer migration). However, there was no pitting, cracking, or crazing on the surface of the treated fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2008–2012, 2004

The Potential of Surfactant Modified Supercritical Fluids for Dissolving Polar Dyes

AbstractThe solubility of different polar dyes in supercritical carbon dioxide and ethane (scCO2 and scC2H6), both modified and unmodified with various surfactants and solvents was determined at temperatures from 323–373 K and in pressure range from 10–45 MPa. The solubility data were correlated with some empirical equations. Furthermore, dyeing experiments with wool and cotton dyes were conducted in order to characterize the impact of modifiers on the dyeing procedure and coloring properties and to prove the practicability of modified fluid systems for commercial procedures.

Density correlation of solubility of C. I. disperse orange 30 dye in supercritical carbon dioxide

The solubility of C. I. Disperse Orange 30 (O30) dye in CO2 has been measured by using a closed-loop (batch) solid-fluid equilibrium apparatus at temperatures between 313 and 393 K and at pressures between 11 and 33 MPa. Kumar and Johnston’s equation based on Chrastil’s concept has been used to describe the experimental solubility data. The solubility versus density plot appears much simpler than the solubility versus pressure plot. The isotherms are nearly straight and parallel to each other, as seen in the previous studies. Peng-Robinson equation of state (PR EOS) has also been used successfully in modeling the dye solubility in supercritical carbon dioxide as a function of pressure or density of the fluid phase. The validity of this method has been verified by the vapor pressure calculation.

Solubilization of ionic dyes in supercritical carbon dioxide: a basic study for dyeing fiber in non-aqueous media

Solubilization of ionic dyes in supercntical carbon dioxide has been investigated using the reverse micellar system. The reverse micelle composed of pentaethylene glycol n-octyl ether and co-surfactant provided suitable solubilizing space for ionic dyes in supercritical carbon dioxide. The effect of the co-surfactant, alcohol, on the stability of the reverse micelle was also investigated. It was found that stability of the reverse micelle and capacities to dissolve water and ionic dyes in the system are greatly dependent on the chain length of alcohol.

Solubilities of C.I. Disperse Red 1 and C.I. Disperse Red 13 in supercritical carbon dioxide

The solubility of two disperse dyes (C.I. Disperse Red 1 and C.I. Disperse Red 13) in supercritical carbon dioxide (SC-CO 2) have been measured at the temperatures of 323.15, 353.15 and 383.15 K and at pressure ranges from 10.0 to 30.0 MPa by using a flow-type apparatus. The experimental results are correlated by an empirical equation, and the Peng–Robinson equation of state (PR EOS) with the conventional mixing rules.