bluuebunny/crossref_metadata_2025 huggingface dataset:
Photofading of reactive dyes on silk and cotton: effect of dye—fibre interactions
Authors: Rastogi Deepali , Sen Kushal , Gulrajani Mohan
Published: June 2006

Fading characteristics of selected bifunctional and monofunctional reactive dyes have been studied on silk and cotton. Dyes were applied in the reactive and hydrolysed forms in order to study the influence of covalent bonding on the photofading of reactive dyes. The active dye‐fibre interaction was found to influence the light fastness of dyes. Reactive dyes forming covalent bonds exhibited better fastness especially on cotton. Only a slight difference in light fastness of fixed and unfixed dyes was observed in the case of silk. The bifunctional reactive dyes, due to the formation of crosslinks, maintain the integrity of the fibre particularly for short periods of light exposure.
Invariant kinetic parameters of dyeing
Authors: Popescu C , Bucur M , Szabo M
Published: June 2006

Based on isothermal exhaustion curves recorded at various temperatures, the possibility of describing numerically the uptake profile of a dyestuff has been investigated. Since the exhaustion process is a complex one, its kinetic parameters depend on the experimental conditions and cannot be used to characterise a group of curves. The alternative method proposed in this study is the use of invariant kinetic parameters for describing the exhaustion of a dyestuff in a dyeing system under various conditions. The concepts have been applied to the exhaustion of two reactive dyestuffs on cotton. The results show that all the isothermal exhaustion curves of a dyeing system can be described by a unique group of three parameters, ni, Ei and Ai.
Improvement of the light fastness of natural dyes: the action of singlet oxygen quenchers on the photofading of red carthamin
Authors: Oda Hironori
Published: June 2006

While the contribution of singlet oxygen quenchers to synthetic dyes has been investigated previously by several workers, there have been few studies pertaining to the use of singlet oxygen quenchers as a means of improving the light fastness of natural dyes. In this paper, the influence of various additives on the photofading of carthamin has been examined in cellulose acetate film. The rate of photofading of the colour was remarkably suppressed in the presence of nickel hydroxyarylsulphonates, while the addition of UV absorbers afforded little retardation in the rate of fading.
The colour fastness of optionally aftertreated metal complex acid dyes on nylon 6.6 during washing in an activated oxygenbleach containing detergent
Authors: Phillips Duncan , Taylor John , Lakhanpal Rajesh , Scotney John , Bevan Geoff
Published: June 2006

Previous studies examining the fading exhibited by optionally aftertreated acid levelling and acid milling dyes on nylon 6.6, during washing in an oxidative‐bleach containing detergent, have been extended to metal complex dyes. It has been shown that, in the main, such dyes exhibit low levels of (oxidativebleach) fading in both the single cycle, stressed UK‐TO (60 °C) test and after 20 machine washes at 50 °C.
Dyeing of wool with temporarily solubilised disperse dyes
Authors: Lee W J , Choi W H , Kim J P
Published: June 2006

Temporarily solubilised disperse dyes derived from aminophenyl‐4‐(β‐sulphatoethylsulphone) have been applied to wool fabric without the use of a levelling agent. By virtue of their characteristic dye structure, excellent levelling properties were observed on wool fabric. Good exhaustion, fixation and fastness test values were also obtained.
Developing a zero‐AOX shrink‐resist process for wool. Part 1: Preliminary results
Authors: El‐Sayed H , Kantouch A , Heine E , Höcker H
Published: June 2006

The efficiency of the proteolytic enzyme papain in conferring shrink‐resistance to wool tops and woven fabrics has been enhanced by pretreatment of the wool with lipase/sodium monoperoxyphthalate/sodium sulphite. This process may be considered as a zero‐AOX shrink‐proofing treatment. The wool samples treated with this system show excellent shrink‐proofed properties. Infrared spectroscopy and X‐ray photoelectron spectroscopy showed that the Buntë salt together with low concentrations of cystine monoxide and cystine dioxide are formed in the course of the reaction. Studies of the surface of the treated wool using scanning electron microscopy have shown the complete absence of wool scales. A mechanism is proposed for shrink resistance in the lipase/sodium monoperoxyphthalate/papain treatment.
Application of the proposed ISO 105‐C09 single cycle test to predict the oxidative‐bleach colour fading of dyed cotton fabrics to repeated laundering with a detergent base containing different bleach and bleach‐activator systems
Authors: Phillips Duncan , Scotney John , Kenyon David
Published: June 2006

It has been shown that the proposed ISO 105‐C09 test, a single cycle test developed to predict the oxidative‐bleach colour fastness of dyed cotton fabrics to repeated laundering in detergents containing the widely used sodium perborate and tetraacetylethylenediamine bleach system, can be reliably extended to systems containing sodium percarbonate and a novel bleach‐activator system.
Improvement of light fastness of natural dyes. Part 2: Effect of functional phenyl esters on the photofading of carthamin in polymeric substrate†
Authors: Oda Hironori
Published: June 2006

The photofading behaviour of carthamin in cellulose acetate film was investigated. A contribution from singlet oxygen to that fading was suggested. Phenyl esters containing nickel sulphonate quenching groups were prepared and the protecting effect of these compounds towards the photofading of carthamin was examined in cellulose acetate film. It is proposed that nickel sulphonate derivatives of phenyl esters can be applied as effective stabilisers against the fading of natural dyes.
Investigation into the synergistic effect between UV/ozone exposure and peroxide pad—batch bleaching on the printability of wool
Authors: Shao Jianzhong , Liu Jinqiang , Carr C M
Published: June 2006

The synergistic effect between UV/ozone exposure and hydrogen peroxide pad‐batch bleaching on the printability of wool has been investigated. The combination treatment can achieve similar printability to that of chlorinated wool but with the added benefits of a whiter base and no formation of adsorbable organohalogens. X‐Ray photoelectron spectroscopy and static secondary ion mass spectrometry indicate that the UV/ozone exposure disrupts surface lipids and disulphide bonds, while vibrational spectroscopy (FT‐IR and FT‐Raman) shows the formation of cysteic acid on the combination treated wool. The process parameters of the peroxide pad‐batch bleaching for UV/ozone exposed wool were optimised.
Improving the environmental and economic aspects of cotton dyeing using a cationised cotton†
Authors: Hauser Peter J , Tabba Adham H
Published: June 2006

One approach to improve the affinity of anionic dyes for cotton is to add cationic dye sites to the fibre. The dyeing behaviour of cotton that had been rendered cationic by reaction with 2,3‐epoxypropyltrimethylammonium chloride was examined. Dye yields and fastness properties are reported for a number of direct, reactive and acid dyes with the modified fibre. Excellent dye yields and colour fastness properties were obtained without the use of electrolytes, multiple rinsings or fixation agents which are normally employed in cotton dyeing.
Effect of content of fluorescent brightening agents on colour change of dyed cotton fabric
Authors: Suganuma Keiko
Published: June 2006

The effect of fluorescent brightening agents at a range of concentrations on the colour change of cotton fabrics was investigated by means of the CIELab colorimetric system. The reduction of b* (i.e. Δb*) was determined as a function of the content of the fluorescent brightening agents. By plotting the values of L* versus Δb* for the dyed fabrics, the critical lightness (Lc*) was calculated which varied according to the hue of the fabrics and the content of the fluorescent brightening agents.
Recovering spectral information using digital camera systems
Authors: Connah D , Westland S , Thomson M G A
Published: June 2006

There is an increasing need to be able to measure colour properties of complex surfaces or images for which traditional spectrophotometers are not suitable. New multispectral imaging systems are being developed but it is not clearly understood how the parameters (such as the number of colour channels, the spectral properties of the channels, and the choice of illuminant) of such systems affect the performance. Furthermore, the effect of sensor and quantisation noise on the overall performance of the system also needs to be considered. This paper describes the development of a mathematical model of a multispectral imaging system that takes into account imaging parameters and noise. The results from the computational model show that increasing the number of colour channels alone in the imaging system does not necessarily allow better estimates of spectral reflectance. The choice of illumination can also, in the presence of noise, greatly affect performance.
Right‐first‐time production in batch dyeing of wool†,‡
Authors: Adamiak U M , Dittrich J‐H , Struckmeier S , Reumann R‐D
Published: June 2006

Powder dyes exhibit even more pronounced sorption behaviour than fibres. The moisture content and weight of the dyes and yarns change according to the ambient relative humidity. In this study, the variations determined in dyehouse stores caused weight changes and subsequent dyeings showed differences of Δ□E* and Δ□L* beyond permissible levels. The detrimental influence on the ability to reach right‐first‐time level of acceptance substantially diminishes the profit margin. The consequence for computer colour‐matching should be the integration of the moisture content of dyes and goods in the recipe calculation. From a technological viewpoint, however, it seems preferable to avoid any fluctuation in relative humidity where dyes and goods are stored. The costs incurred for investment in humidity control will pay in the long run and the factor of moisture content may be entirely negligible.
Co‐application of hydroxyalkyl dyes and polyphosphonic acids to cotton to achieve dye—fibre covalent bonding
Authors: Gillingham Estelle L , Lewis David M , Srikulkit Kawee
Published: June 2006

The dyeing of cotton to a high standard of wet‐fastness with hydroxyalkyl dyes and a polyphosphonatecrosslinker system has been investigated. Dyes containing hydroxyalkyl groups were prepared, by the reaction of commercial reactive dyes with ethanolamine, and applied to cotton fabric in the presence of polyphosphonic acid crosslinking agents using cyanamide as a catalyst. The application was carried out using a pad‐thermosol method. The effects of cyanamide concentration, the nature of the crosslinker and the type of hydroxyalkyl dye were studied in detail. It was concluded that multifunctional polyphosphonates are capable of producing dyeings on cellulosic fibres exhibiting a high degree of covalent bonding (fixation). The efficiency of dye fixation at ca. 2% pure dye (owf), obtained from this method, was greater than 90%.
Dyeing studies with hydroxyanthraquinones extracted from Indian madder. Part 1: Dyeing of nylon with purpurin†
Authors: Gupta Deepti , Kumari Shipra , Gulrajani Mohan
Published: June 2006

Purpurin (1,2,4‐trihydroxyanthraquinone) is the major colorant present in the roots of Indian madder (Rubia cordifolia). Its structure is similar to that of disperse dyes. To gain an understanding of the dyefibre interactions involved, kinetic and thermodynamic studies have been conducted with purpurin on nylon fibre. Dyeing corresponds to the Nernst isotherm as linear isotherms were obtained. The dye is found to be sensitive to pH and high temperature. The rate of dye uptake, diffusion coefficient, standard affinity, heat of dyeing and entropy have been calculated and discussed.
Alkali degumming of decorticated ramie
Authors: Bhattacharya S D , Das Ashok K
Published: June 2006

The degumming action of ramie with sodium metasilicate, alone or in combination with other alkali solutions such as sodium carbonate and trisodium phosphate, has been evaluated and optimum conditions determined. The performance of degumming has been assessed in terms of weight loss, whiteness index and colour strength of the degummed fibres.
Relationship between the solubility of disperse dyes and the equilibrium dye adsorption in supercritical fluid dyeing
Authors: Tabata Isao , Lyu Jinha , Cho Sungmi , Tominaga Tomoko , Hori Teruo
Published: June 2006

In order to understand the dyeing behaviour of synthetic fibres in supercritical carbon dioxide, the solubility of some disperse dyes in supercritical fluid, as well as the rate of dyeing and the equilibrium adsorption of these dyes, have been studied. Dye solubility was measured by a dynamic analytic method at a range of pressure (7.5–25 MPa) and temperature (50–145 °C). The apparent rate of dyeing was measured and the dyeing isotherm was obtained by plotting the equilibrium dye adsorption against the equilibrium dyebath concentration. Linear isotherms were obtained when poly(ethylene terephthalate) samples were dyed with the disperse dyes. The mechanism of dyeing using supercritical carbon dioxide was discussed by considering the solubility, the dyeing rate and the dyeing isotherm.
Two‐step durable press treatment of cotton fabric
Authors: Xu Weilin , Cui Weigang , Li Wenbin , Guo Weiqi
Published: June 2006

In this paper cotton fabrics were treated by two different methods with polycarboxylic acids (citric acid and butanetetracarboxylic acid) for durable press performance. The first was a two‐step method in which the fabric was initially treated with citric acid and then treated by butanetetracarboxylic acid. The other was a mixed method in which the fabric was treated with a solution containing the two mixed polycarboxylic acids. Following the treatments, the wrinkle recovery angle, strength and strength retention of the resulting fabric were measured and compared.
Dyeing in catalase‐treated bleaching baths
Authors: Tzanov T. , Costa S. , Guebitz G.M. , Cavaco‐Paulo* A.
Published: June 2006

The conventional rinsing after bleaching to remove the residual hydrogen peroxide, harmful to the reactive colorants, was replaced by enzymatic cleaning using catalases. The catalase‐treated bleaching liquor was reused for dyeing. Though no hydrogen peroxide was detected after the enzymatic process, the bleaching bath composition caused unacceptable colour changes on dyed fabrics. By varying the parameters of the dyeing process – dye, salt, alkali and enzyme concentrations – the colour difference could be reduced significantly and a good dyeing result could be achieved.
Comparison of the performance of zeolite‐containing and phosphate‐containing ECE reference detergents in three different wash fastness tests
Authors: Phillips D. , Taylor J. , Lakhanpal R. , Scotney J. , Bevan G.
Published: June 2006

This paper describes a study of the wash fastness of a number of dyed cotton and nylon substrates in the C06/C2S, C08/C2S and M&S C4A (60 °C) wash fastness tests, using both zeolite‐ and phosphate‐containing detergent formulations. The staining of adjacents was generally shown to be at least 0.5 grey scale units less in all three tests when the zeolite‐containing standard detergent formulation was used. Staining in the C06/C2S test was usually 0.5 grey scale units higher than in the corresponding C08 and M&S C4A test because of the lower liquor ratio at which the former test was conducted. It is therefore recommended that, if the C08 test is to set demanding levels of colour fastness, the liquor ratio at which it is conducted should be reduced to ca. 30:1.
Thermal memory of polyester stabilised at different temperatures
Authors: Gacén* J. , Maillo J. , Gacén I.
Published: June 2006

Polyester filaments yarns stabilised at different temperatures (180–220 °C) in the production plant have been treated under similar thermal conditions to those dyed at high temperature and dyed in the presence of a carrier. The original and treated substrates have been characterised through differential solubility and iodine sorption techniques. Differential solubility measurements highlight the differences in fine structure of substrates stabilised at different temperatures and then dyed under different conditions.
Degradation of Remazol Black B dye and its simulated dyebath wastewater by advanced oxidation processes in heterogeneous and homogeneous media
Authors: Arslan I. , Balcioglu I.A.
Published: June 2006

This study focused on the degradation of hydrolysed Remazol Black B (CI Reactive Black 5), a common diazo reactive dye, in aqueous solution. In the presence of various dye auxiliary chemicals a typical Remazol Black exhausted dyebath liquor simulated, which was then treated with homogeneous [ozonation with hydroxy ions, and Fe(II) or Fe(III) with hydrogen peroxide] and heterogeneous (titanium dioxide with UV‐A irradiation) advanced oxidation processes. Treatment performance of the investigated advanced oxidation systems was comparatively assessed in terms of the environmental sum parameters total organic carbon, biochemical oxygen demand and spectrophotometric measurements. The results obtained clearly reveal that the investigated advanced oxidation processes are capable of completely decolourising and partially mineralising the dye solution and its simulated dyebath effluent under predetermined reaction conditions. During the application of alkaline ozonation at an ozone dose of 2340 mg/ml, a three‐fold biodegradability enhancement was observed.
High performance squarylium dyes for high‐tech use
Authors: Kim* S‐H. , Han S‐K.
Published: June 2006

The syntheses of various squarylium dyes are reviewed in this paper. Possible applications of these dyes are also discussed, including their electrochromic, electroluminescence, electrophotographic and metal ion sensing properties.
Studies on indigo dyeing and diffusion by the film roll method
Authors: Zhou X.
Published: June 2006

The influence of reducing agent, indigo concentration and dyebath pH on indigo dyeing and diffusion was studied for the film roll method. An almost linear relationship between the indigo concentrations in the dyed film and in the dyebath was maintained throughout the experiments. Two different calculation methods were used to obtain the diffusion coefficient and the surface indigo concentration in the film. Similar surface indigo concentrations were obtained from the two methods, but a lower diffusion coefficient was obtained by the approximate integral method. It was found that the dyebath pH is the dominant factor influencing the rate of diffusion of indigo and the colour yield of the dyed film. The dyebath pH also had a considerable influence on the reduction of indigo to leuco‐indigo, a step that is essential to the dyeing process.
Kinetic and spectroscopic study of heterogeneous oxidation of azo dyes using hypochlorite
Authors: Oakes* J. , Gratton P. , Wilkes I. , Gordon‐Smith T.
Published: June 2006

A combined kinetic and spectroscopic investigation is described of the heterogeneous oxidation (by hypochlorite) of an azo dye (Remazol Red RB) reactively bound to cotton. It is shown that the physical state of bound dye (e.g. its pKA and tautomeric form) and its oxidation profile with pH are similar to those of dye in homogeneous solution. Analyses are presented which suggest that the mechanism of oxidation in the two environments is similar. The oxidation of azo dyes of pyrazolone and pyridone types occurs at similar rates to arylazonaphthol dyes. This suggests that oxidation kinetics are independent of groups attached either side of the azo linkage, confirming that the site of attack is the more nucleophilic nitrogen atom of the azo group of the common anion.
Development of redox resin using metal phthalocyanine derivatives
Authors: Sakamoto* K. , Ohno‐Okumura E.
Published: June 2006

Utilisation of the reduction and oxidation properties of metal phthalocyanine derivatives was carried out for the development of new types of redox resin. The redox resins were prepared by fixing the synthesised metal phthalocyanine tetrasulfonic acids onto ion exchange resins. The adsorption properties of metal phthalocyanine tetrasulfonic acid onto an anion exchange resin was found to be the Freundlich type with the characteristics of both chemisorption and physisorption. The capabilities of the redox resins were estimated with the decomposition of hydrogen peroxide which was shown to increase with increasing reaction time. The capability was found to be dependent on the central metal in the metal phthalocyanine tetrasulfonic acid.
Dyeing of cotton with indigo using iron(II) salt complexes
Authors: Chavan R.B. , Chakraborty J.N.
Published: June 2006

The use of gluconic acid as a ligand for complexing iron(II) salts and for vat dyeing of cotton has been reported previously. The present paper reports the observations on the use of iron(II) salts complexed with such ligands as tartaric acid and citric acid for the reduction of indigo at room temperature and subsequent cotton dyeing. This study includes the measurement of reduction potentials of various iron complexes, their effect on dye uptake and the deposition of iron on dyed fabric.
Study on ozone bleaching of cotton fabric – process optimisation, dyeing and finishing properties
Authors: Prabaharan* M. , Rao J. Venkata
Published: June 2006

In this work the role played by the presence of moisture and pH during ozone bleaching of grey cotton fabric and the design features of the ozone application chamber are reported. The results are explained with the help of a simplified model. The dyeing and resin finishing properties of ozone‐bleached fabric are compared with those of hydrogen peroxide‐bleached fabric.
Chemical finishing of cotton using reactive cyclodextrin
Authors: Hebeish A. , El‐Hilw Z.H.
Published: June 2006

Chemical modification of cotton cellulose in the fabric form was investigated through reaction with monochloro‐β‐cyclodextrin. The reaction involves single ended substitution and crosslinking. Investigations into the factors affecting these reactions occurring in the presence of N‐methylol compound (resin) and/or a reactive dye were undertaken. The treatment was carried out as per the conventional pad–thermofixation method.
Dispersant‐free dyeing of polyester with temporarily solubilised azo disperse dyes from 1‐substituted‐2‐hydroxypyrid‐6‐one derivatives
Authors: Lee J J , Han N K , Lee W J , Choi J H , Kim J P
Published: June 2006

Four temporarily solubilised azo disperse dyes based on 1‐substituted‐2‐hydroxypyrid‐6‐one were synthesised and characterised. The dyes showed high extinction coefficients and had a yellow shade on polyester fabric. They were successfully applied to polyester without the use of dispersants and the optimum pH was found to be 5. It was found that the dyes could be alkali‐cleared due to ionisation of the dye under mild alkaline conditions. The dyes exhibited good to excellent fastness properties on the polyester fabric.
Chemical modification of cotton to improve fibre dyeability
Authors: Wang Huitu , Lewis D M
Published: June 2006

A new fibre‐reactive quaternary compound containing an acrylamide residue was synthesised and used as a cotton modification reagent. The agent was applied to cotton fabrics using a pad‐bake process. It was found that the treated fibre could be dyed with reactive dyes without the addition of salt or alkali. The reactive dyes were almost completely exhausted and showed a high degree of covalent bonding with the pretreated cellulose. The effect of varying the pretreatment conditions was investigated and the optimum conditions for pretreating and dyeing were established.
Quantitative prediction of the degree of pollution of effluent from reactive dye mixtures
Authors: Kwok W Y , Xin J H , Sin K M
Published: June 2006

By using mathematical formulae developed in previous studies, certain pollution parameters of dye effluent obtained from reactive dyeing with a single dye can be predicted with good accuracy. In this study, the degree of pollution of reactive dyeing effluent using dye mixtures was also predicted by other approaches, such as linear and non‐linear regression. The prediction accuracy was found to be satisfactory.
Contribution of free radicals to ozonation of spent reactive dyebaths bearing aminofluorotriazine dyes
Authors: Arslan‐Alaton Idil , Kornmueller Anja , Jekel Martin R
Published: June 2006

Laboratory‐scale ozonation of spent dyebath simulations bearing aminofluorotriazine‐type reactive dyes was investigated. It was particularly aimed at interpreting the kinetic behaviour of ozone by applying a simple fractional hydroxyl radical scavenger (carbonate/bicarbonate alkalinity) test at varying pH in the absence and presence of sodium carbonate. Complete decolorisation (first‐order decolorisation rate constant kD, 0.5–1.0 1/min at λ 436 nm) as well as partial mineralisation (TOC removal, 5–9%) and dearomatisation (UV254 removal, 55–83%) could be achieved after 1 h of ozonation, whereas detoxification was only improved from ED20 30 to 53%. This study demonstrated that in the presence of sodium carbonate, neither molecular ozone nor hydroxyl radicals play an important role in dye oxidation. It has been proposed that other free radicals (carbonate or bicarbonate radicals) might be the dominant oxidising agents.
Effect of surfactants on the thermodynamic properties of Methyl Orange dye in buffered solutions
Authors: Dakiky M , Khamis M , Manasra A , Takrouri K
Published: June 2006

The apparent thermodynamic parameters of ionisation and the association constants of the two forms of Methyl Orange were evaluated in the presence of different surfactants (TX‐100 as nonionic, CTAB as cationic and SDS as anionic). The enthalpy of ionisation of the dye in aqueous solution and at different surfactant concentrations is obtained from a novel thermochromic method and is found to decrease in aqueous medium in CTAB and TX‐100 micelles and to increase in the case of SDS micelles. The apparent ionisation constant of the dye is evaluated spectrophotometrically for each surfactant concentration and type. The apparent Gibbs free energy, entropy of ionisation and association constants are also calculated. The results are discussed in light of the stabilisation of the two forms of the dye in the micellar core of the different surfactants and their effect on properties of the bulk solution is examined.
Reactive dyeing systems for wool fibres based on hetero‐bifunctional reactive dyes. Part 1: Application of commercial reactive dyes
Authors: Cho Ho Jung , Lewis D M
Published: June 2006

The wool dyeing properties, such as exhaustion and fixation parameters, of selected hetero‐bifunctional Sumifix Supra dyes and some other commercial reactive dyes were quantified under various dyebath pH conditions. Studies of the dyeing of wool serge fabric indicated that Sumifix Supra dyes could produce reasonably high fixation values. However, remarkably improved fixation values were obtained when these dyes were pre‐activated to the vinylsulphone form and dyed in this form, especially at low pH values (pH 4 or lower).
A factorially‐designed study of physicochemical reactive dye colour removal from simulated cotton textile processing wastewaters
Authors: Carvalho G , Delée W , Novais J M , Pinheiro H M
Published: June 2006

The process performance of coagulation to remove reactive dyes from dyehouse effluent is affected by multiple factors, which can be best examined in factorially‐designed experiments. A preliminary jar‐test procedure was used to select coagulants and the optimal pH and coagulant dosage ranges. An inorganic salt (ferrous sulphate) and an organic polymer (DEC 50) were selected for further studies. Factorially‐designed jar‐test experiments were performed with different compositions of a synthetic cotton processing wastewater to determine which factors most affected colour removal and highlight interactions between them. Some additives, such as an oxidative desizing agent and a peroxide stabiliser, favoured colour removal within specific concentration ranges. The presence of sizing agents and surfactants reduced process efficiency. Increasing concentrations of ferrous sulphate could counteract this, but would result in higher sludge disposal costs.
Influence of additives on the fabric stiffness and colour depth of viscose printed with a guar gum thickener and a reactive dye
Authors: Kokol V , Schneider R , Šostar‐Turk S
Published: June 2006

The effect of additives in a printing paste containing guar gum thickener and bireactive dye for cellulose printing was studied. The efficiency of the additives with respect to their chemical structure and concentration and the efficiency in combination with thickeners of different types (nonsubstituted, different degrees of carboxymethylation) and different concentrations (solid content) was investigated by assessing the fabric stiffness, colour depth, dye penetration, the viscosity and viscoelasticity of the printing paste and the printing paste add‐on. Some additives caused a decrease in the fabric stiffness to an acceptable degree with little effect on the colour depth. Dye penetration was found to be exclusively additive‐dependent. Spectroscopic and rheological investigations confirmed the reduction of dye/guar gum interactions due to the occurrence of additive/guar gum and additive/dye interactions. The best quality prints were obtained using a printing past containing a nonionic surfactant and a highly carboxymethylated guar gum thickener.
Dyeing natural fibres in supercritical carbon dioxide using a nonionic surfactant reverse micellar system
Authors: Sawada K , Takagi T , Jun J H , Ueda M , Lewis D M
Published: June 2006

A reverse micellar system in supercritical carbon dioxide has been developed as a dyeing medium. Water‐soluble dyes such as reactive dyes and acid dyes could be sufficiently solubilised in the interior of a specially constituted reverse micelle. Protein fabrics, silk and wool, were satisfactorily dyed even in deep shades with conventional acid dyes without any special pretreatment. Cotton cellulose fabric was also dyed with conventional reactive dyes when the electrostatic force of repulsion between dye and cotton was eliminated. Compared to previously proposed supercritical dyeing methods, dyeing of fabrics with this system could be performed at low temperatures and pressures in a short time.
Dyeing equilibria: interaction of direct dyes with cellulose substrates
Authors: Porter John J
Published: June 2006

The traditional Freundlich equation used to correlate direct dye sorption on cellulose is compared to the Langmuir equation for correlating the same data. Results taken from six different direct dyes are presented that show a much better correlation of the data is obtained with the Langmuir equation indicating that the interaction of dyes with the substrate is rather specific. The specific nature of the sorption process is compared to acid dye sorption on aminised cotton which also is shown to be Langmuir type. Explanation of the sorption of mixtures of direct dyes is also discussed as being better interpreted in terms of the Langmuir sorption.
Quantum efficiency of fluorescent dyes in cloth
Authors: Rong Li , Feng Gu , Jiangnin Che , Donghui Chen
Published: June 2006

Based on an additional hypothesis of the Kubelka‐Munk theory, different equations describing the propagation of fluorescent light in cloth are proposed and a much simpler formula relating to the quantum efficiency of fluorescent dyes with spectral radiance factor is obtained. The polyester, wool and cotton samples were dyed with disperse and acid fluorescent dyes in the laboratory. With the spectral radiance factor of fluorescent samples measured via the two‐mode method, the quantum efficiencies are evaluated in terms of the new formula. These show good agreement to quantum efficiencies calculated using an alternative formula.
Review on decolorisation of aqueous dye solutions by low cost adsorbents
Authors: Sanghi Rashmi , Bhattacharya Bani
Published: June 2006

Textile wastewater presents a challenge to conventional physico‐chemical and biological treatment methods. Liquid‐phase adsorption has been shown to be highly efficient for the removal of dyes and other organic matters from process or waste effluent. Many different types of adsorbent are used to remove colour from wastewater among which the most widely used material is activated carbon. Since activated carbon is expensive and necessitates regeneration, attempts have been made to substitute alternatives that are biodegradable, low cost and/or waste materials. This article presents the investigations carried out by numerous researchers on the use of different kinds of adsorbents and their adsorption capacities for the removal of specific dyes from textile wastewater.
Synthesis of N,N‐diethyl‐N‐{4‐[(E)‐(4‐nitrophenyl)diazenyl]phenyl}amine via in situ diazotisation and coupling in supercritical carbon dioxide
Authors: Hooker Jacob , Hinks David , Montero Gerardo , Conlee Christopher
Published: June 2006

The synthesis of azo dyes via a conventional aqueous‐based diazotisation and coupling reaction requires the use of relatively high concentrations of mineral acids, which leads to high electrolyte concentrations in wastewater. Reported in this paper is an environmentally benign one‐pot method for the synthesis of a nonionic azo dye, N,N‐diethyl‐N‐{4‐[(E)‐(4‐nitrophenyl)diazenyl]phenyl}amine, in supercritical carbon dioxide without using a mineral acid. The product yield increased significantly with temperature, with 91% theoretical yield afforded at 80 °C. The pressure of the system had little influence on product yield.
Printing of cationised cotton with reactive dyes
Authors: Kanik Mehmet , Hauser Peter J
Published: June 2006

The printing properties of cationised cotton that had been pretreated with 2,3‐epoxypropyltrimethylammonium chloride were examined. Fixation (steaming) time, colour yields, colorimetric properties, fastness properties, staining of the white grounds and penetration behaviour were evaluated for a number of reactive dyes with cationised cotton fabrics. The cationisation of cotton was found to be very effective in reducing steaming times and washing off processes, and in increasing colour yield. Fastness and other properties of the printings are also discussed.
Photocatalytic degradation of CI Acid Green 25 and CI Acid Red 88 in aqueous suspensions of titanium dioxide
Authors: Saquib M , Muneer M
Published: June 2006

The photocatalytic degradation of CI Acid Green 25 and CI Acid Red 88 in aqueous suspensions of titanium dioxide has been investigated by monitoring the depletion of the total organic carbon content as a function of irradiation time under a variety of conditions. The degradation rates were found to be strongly influenced by pH, catalyst concentration, substrate concentration and different titanium dioxide powders. The degradation of CI Acid Red 88 was found to occur faster than that of CI Acid Green 25. The degradation products were analysed by gas chromatography‐mass spectrometry and probable pathways for the formation of products are proposed.
A new chemical aid for criminal investigation: dyes and latent prints
Authors: Castelló Ana , Alvarez Mercedes , Verdú Fernando
Published: June 2006

Criminalistics is a field in which there are many opportunities for the practical application of chemical reagents and the use of analytical methods that provide answers to enigmas at crime scenes. Common reagents in biochemical and medical test methods can be useful for criminalistics (forensic science). Dyes are one type of reagent that can be used in obtaining crime scene evidence. This work describes a new application of CI Solvent Black 3 dye in the location of latent fingerprints. The results show that CI Solvent Black 3 can be successfully applied in the location and development of recent and non‐recent latent fingerprints on porous surfaces.
Electrochemical oxidation of reactive dyes: method validation and application
Authors: Gutiérrez M.C. , Pepió M. , Crespi M.
Published: June 2006

Electrochemical oxidation is a very effective technique for wastewater processing and, in the textile industry, it can be employed to remove colour from residual dyeing and washing liquors. In previous studies, the main factors were established for the control of the electrochemical removal of reactive dyes from textile wastewater. Mathematical models were proposed for the decolorisation of these dyes and for the electrical consumption. In the present work, these models are analysed and a three‐step methodology is established in order to determine whether a dye can be removed from wastewater by electrochemical treatment. This methodology is applied and verified on a further four reactive dyes. The mathematical models are also employed to evaluate the colour removal from textile wastewater samples containing reactive dyes.
Detection of hydroxyl radicals in photoirradiated wool, cotton, nylon and polyester fabrics using a fluorescent probe
Authors: Millington K.R. , Kirschenbaum L.J.
Published: June 2006

Generation of hydroxyl radicals in the presence of buffered terephthalate solution produces flourescent 2‐hydroxyterephthalate. Wool, nylon, cotton and polyester all generate hydroxyl radicals when irradiated with UVA light, and to a lesser extent with blue light, in terephthalate solution. Trace metal ions (particularly iron and copper) contribute to hydroxyl radical generation in wool and cotton. UVA irradation of wool in deuterated solution does not affect the concentration of hydroxyl radicals or the amount of yellowing observed relative to undeuterated solution. This suggests that 1O2 is not involved in the wet photoyellowing of wool. Although the photoinitiation stages are clearly different, it is likely that similar free radical processes are responsible for both hydroxyl radical production and wet photoyellowing in all four fibre types. This straight forward fluorescence technique has potential to correlate the free radical photodegeneration of fibres in the presence of various additives designed to improve performance.
Synthesis and application of a hetero‐bifunctional disulphidebis(ethylsulphone/monochlorotriazine) reactive dye
Authors: Youssef Y.A. , Mousa A.A.
Published: June 2006

The behaviour of a heterobifunctional reactive dye based on a disulphidebis(ethylsulphone/monochlorotriazine) reactive system has been investigated. Relatively high degrees of exhaustion and fixation were achieved for cotton fabrics dyed with the disulphidebis(ethylsulphone/monochlorotriazine) reactive dye compared to bifunctional sulphatoethylsulphone/monochlorotriazine and/or conventional monofunctional monochlorotriazine reactive dyes. The results also indicate that the fastness properties are approximately the same for all the dyes studied in this investigation.
Study of physico‐chemical surface treatments on dyeing properties of polyamides. Part 1: Effect of tetrafluoromethane low temperature plasma
Authors: Yip J. , Chan K. , Sin K.M. , Lau K.S.
Published: June 2006

Polyamide (nylon 6) fabrics have been treated with tetrafluoromethane low temperature plasma and then dyed with commercially available acid and disperse dyes. The morphology of the treated surfaces has been examined by scanning electron microscopy and chemical surface changes characterised by X‐ray photoelectron spectroscopy. Dyeing results show that the plasma treatment slows down the rate of exhaustion but does not reduce the amount of absorption of acid dyes. The dyeing properties of disperse dyes on plasma‐treated nylon fabrics changed markedly when compared with untreated fabric. A slight improvement in colour fastness is seen with the treated sample. The dyeing process has only a minor effect on the water‐resistant surface, indicating that a stable surface has been achieved by the treatment. For Part 2 of this study, see page 31 of this issue of Coloration Technology.
Study of physico‐chemical surface treatments on dyeing properties of polyamides. Part 2: Effect of UV excimer laser irradiation
Authors: Yip J. , Chan K. , Sin K.M. , Lau K.S.
Published: June 2006

Polyamide (nylon 6) fabrics were irradiated with a 193 nm argon fluoride excimer laser and the effects on the dyeing properties of the fabrics were studied. Chemical analysis indicated that carbonisation occurred in the laser‐irradiated samples. The laser treatment breaks the long chain molecules of nylon, increasing the number of amine end‐groups which change the dyeing properties of acid and disperse dyes. The results suggest that laser treatment could be used to improve the dyeing properties of nylon fabric with a disperse dye.
A correction algorithm for reflectance measured with optical glass
Authors: Jiangning C. , Donghui C.
Published: June 2006

A correction algorithm for reflectance measured with optical glass is proposed. The algorithm consists of a correction formula that gives different correction coefficients for reflectance at different wavelengths and a measurement of transmittance of the glass. The true, raw and corrected reflectances are compared, verifying the validity of the correction algorithm.
Dyeing kinetics of wool fabrics pretreated with a protease
Authors: Riva A. , Algaba I. , Prieto R.
Published: June 2006

Dyeing kinetics of wool fabrics treated with different concentrations of an enzyme of the protease type are studied in this work. Dyeing isotherms with an acid and a premetalised 2:1 dyestuff were carried out and the fit of several kinetic equations to the experimental results determined. The absorption rate constants and activation energies were calculated.
Surface modification to improve dyeing of cotton fabric with a cationic dye
Authors: Pisuntornsug C. , Yanumet N. , O'Rear E.A.
Published: June 2006

Sodium styrene sulphonate, a polymerisable anionic surfactant, was polymerised on cotton to impart a negative charge on the fibre surface. This enabled the fibre to be dyed with a cationic dye with no addition of salt. The treated cotton was dyed with a cationic dye to determine the amount and uniformity of the coating. The resulting dyed treated fabric shows good washing fastness at 30 °C and excellent dry rub fastness.
Blade coating of fabrics: rheology and fluid penetration
Authors: Davard F. , Dupuis D.
Published: June 2006

The coating of fabrics generally involves the use of complex fluids as coating compounds. During the coating process, these compounds are submitted to various stresses. This paper investigates the influence of the rheological properties of the fluid on its penetration into the fabric. Experiments were performed with several kinds of model polymer solutions on a cotton fabric. Penetration coefficients were obtained from reflectance measurements on the face and reverse sides of the fabric. The results show that there are competitive effects between shear‐thinning which promotes penetration and elasticity which tends to reduce it.
Use of standing bath technique in peroxide bleaching of cotton
Authors: Shukla S.R. , Maheshwari K.C.
Published: June 2006

The use of a standing bath technique in hydrogen peroxide bleaching of cotton fabric was investigated. Two non‐silicate stabilisers, a laboratory‐formulated inorganic stabiliser and a commercial organic stabiliser, were used. The bleaching recipe was optimised for maximum whiteness and then used for the standing bath technique by replenishing the bath with the equivalent peroxide concentration and maintaining the pH. The level of replenishment of the stabiliser was varied up to 70% of the initial amount of stabiliser. The results, as assessed by CIE whiteness index, indicate that it is only possible to achieve similar whiteness levels to bleaching without a standing bath by replenishing the stabiliser with a large proportion of the original amount.
Process of dyeability modification and bleaching of cotton in a single bath
Authors: Srikulkit K. , Larpsuriyakul P.
Published: June 2006

Graft polymerisation of the cationic monomer, methacryloylaminopropyltrimethylammonium chloride (MAPTAC), onto scoured cellulose was carried out in the bleaching process, aiming at modifying the fibre using a single bath. The extent of MAPTAC fixation on cellulose was measured. The bleaching performance of hydrogen peroxide in the presence of the modifying agent was found to be slightly reduced. The modified bleached cotton fabric was then dyed with a commercial reactive dye in the absence of salt. The dye uptake and colour strength of the modified fabric was markedly increased with an increase in the concentration of MAPTAC. This was attributed to the presence of the cationic groups of the MAPTAC which played a crucial role in attracting the anionic dyes from the dyebath. The results suggest that the dyeing properties of the modified fabric are closely dependent on the efficiency of MAPTAC fixation on cellulose during concurrent modifying and bleaching of cotton.
Preliminary studies on the use of cyanines as ligands in dye‐affinity chromatography of proteins
Authors: Pardal A.C. , Nunes M.J. , Gama A.M. , Queiroz J.A. , Almeida* P.
Published: June 2006

An isothiocyanato‐functionalised cyanine was synthesised, characterised, immobilised on agarose gel and the dye‐affinity adsorbent ability for purifying some standard proteins (e.g. bovine serum albumin, trypsin and chymotrypsin) was analysed. The influence of mobile phase composition on the chromatographic behaviour of these proteins was also studied. A selective interaction between the studied proteins and the immobilised cyanine was obtained.
Cationic pretreatment of cotton fabric for anionic dye and pigment printing with better fastness properties
Authors: El‐Shishtawy* R.M. , Nassar S.H.
Published: June 2006

Improved printability with pigment and anionic dyes was obtained after simple cationisation of cotton fabrics with Solfix E. Different print paste formulations were used for printing cationised cotton fabrics with pigment, acid and direct dyes. Print pastes containing a synthetic thickener or a pigment emulsion showed good suitability for printing with pigment and pastes containing Meypro‐gum as a thickener showed good printability with anionic dyes. The prints obtained on cationised cotton showed better overall fastness properties than prints obtained on untreated cotton. After repeated washings, the prints on cationised cotton showed a much smaller percentage colour loss than the prints on untreated cotton fabric.
The effect of various anti‐setting systems in wool dyeing. Part 1: Hydrogen peroxide based systems
Authors: Kim J. , Lewis* D.M.
Published: June 2006

Extensive setting of wool fabrics occurs during piece dyeing at the boil and gives rise to adverse changes in dimensional stability such as variable hygral expansion, loss in tensile strength and the appearance of unsightly marks such as ‘crow's‐feet’ on the fabric surface. Anti‐setting agents such as stabilised hydrogen peroxide systems have thus been marketed to control this problem. Much has been published regarding the anti‐setting and hygral expansion properties achievable but little information regarding the chemical effect of boiling wool with acidic solutions of hydrogen peroxide is available. Fourier transform infrared reflectance spectroscopy has thus been extensively used to quantify the chemical changes occurring on boiling wool in such aqueous solutions of hydrogen peroxide.
Dyeing and fastness properties of benzodifuranones, naphthodifuranones and naphthofuranonepyrrolidones
Authors: Yoon C. , Hallas G.
Published: June 2006

Dyeings were carried out on polyester with benzodifuranones, naphthodifuranones and naphthofuranonepyrrolidones (which had been synthesised previously) to study dyeing properties. Symmetrically and asymmetrically substituted naphthodifuranones showed poor dyeing properties in terms of dyeing and fastness. Asymmetrically substituted red benzodifuranones showed excellent dyeing properties and fastness. Asymmetrically substituted blue benzodifuranones showed good dyeing properties; however, the colour hue was dull and the light fastness was inferior. The naphthofuranonepyrrolidones showed similar dyeing and fastness to those of symmetrically substituted naphthodifuranones, but the colour hue was duller.