• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.154-160
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• 1995

Dyeing behavior of Silk/Cationic dyeable polyester(CDP) mixed filament was investigated by using a cationic dye. The effect of pH, temperature and additives such as carrier, levelling agent and salt were examined for each silk and CDP component of mixed filament in order to find out the optimum dyeing condition. Based on these results, the dyeing behavior was investigated for Silk/CDP mixed filaments concering various dyeing parameters. The dye adsorption was significantly changed on the dyeing temperature, carrier addition and pH of the dyebath. Specially, the dye migration phynomena were observed for a mixed filament, showing that the dyes initially observed on the surface of silk fiber migrate to the CDP component during a dyeing process. The dyeing of Silk/CDP mixed filaments accompanied by dye migration and as a result, dye adsorption can be developed only for a CDP component. Therefore, the control of dyeing temperature is most important for a Silk/CDP mixed filament, in order that both silk and CDP component are able to be dyed by a cationic dye simultaneously in one bath/one dye system.

• Textile Coloration and Finishing
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• v.19 no.1 s.92
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• pp.12-16
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• 2007

Exhaustion increase using cationic dyes on polyamide fibers are not easy work due to the limited amounts of the functional end groups(-COOH) in the substrates. Therefore, to enhance dye exhaustion, polyamide fibers are required to be modified onto desired surface properties of the fibers using anionic bridging agent. In this study, synthetic tanning agent for pre-treatment finishing and cationic dye(berberine chloride) for dyeing of polyamide fibers were used. For surface modification, polyamide fibers were pre-treated with synthetic tanning agent at various concentrations and temperatures. The increased concentration and temperatures of synthetic tanning agents had resulted in exhaustion increase. The modified polyamide substrates skewed increased cationic dyeing exhaustions and the corresponding dyeing results from treated samples represented higher exhaustion properties than those of non-treated counterpart. The increased dyeing effects of cationic dye can be attributed to the supplied ionic interaction and electrostatic attraction sites on the surface of polyamide substrates.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.525-532
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• 2005

Polyelectrolyte titration, which was called colloid titration is based on the stoichiometric reaction between oppositely charged polyelectrolytes, This can be used, for instance, to determine the charge density of a cationic polyelectrolyte, using an anionic polyelectrolyte of known charge density, such as potassium polyvinyl sulfate (PPVS). The technique requires a suitable method of end-point detection and there are several possibilities. In this work, two methods have been investigated: visual titrimetry based on the color change of a cationic dye (o-toluidine blue, o-Tb) and spectrophotometry based on the absorbance change corresponding to the color change of the same dye. These have been applied to several cationic polyelectrolytes with different charge density and molecular weight. In all cases, the cationic charge was due to quaternary nitrogen groups. In the case of cationic dye, it was shown that the sharpness depends on the charge density of cationic polyelectrolyte. With the polyelectrolytes of lower charge density, the binding to PPVS is weaker and binding of the dye to PPVS can occur before all of the polyelectrolyte charge has been neutralized. However, by carrying out titrations at several polyelectrolyte concentrations, good linear relationships were found, from which reliable charge density values could be derived. Effects of pH and ionic strength were also briefly investigated. For cationic polyelectrolytes (copolymers of acrylamide and dimethylaminoethy] acrylate), there was some loss of charge at higher pH values, probably as a result of hydrolysis. Increasing ionic strength causes a less distinct color change of o-Tb, as a result of weaker electrostatic interactions.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.1-7
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• 2012

Dyeing and fastness characteristics of 100% meta-aramid fiber were investigated with cationic dyes and swelling agents under various dyeing conditions such as dyeing temperature and pH of dye bath. Dye exhaustion started at around $80^{\circ}C$ and settled down at $130^{\circ}C$. Among swelling agents used, N-methyl formanilide showed comparatively higher K/S values comparing to 1-phenoxypropan-2-ol. Under weak acidic conditions in the range pH 5 to 7, the exhaustion of cationic dyes could be enhanced leading to higher adsorption and stability of colorimetric property. Wash and rubbing fastness were generally good but low light fastness found can be attributable to the poor photo-stability of the cationic dyes.

• Fibers and Polymers
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• v.7 no.1
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• pp.20-25
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• 2006

The alkaline dissolution behavior of sea-island type polyarnide microfibers were successfully monitored using a cationic dye staining method. Weight reduction behavior of the alkali-treated microfiber fabrics and the treated fabrics stained with cationic dye were investigated in a comparative manner. The termination of dissolution monitored by both methods was also confirmed by scanning electron microscopy.

• Textile Coloration and Finishing
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• v.7 no.2
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• pp.1-8
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• 1995

Polymer cationic agent was prepared by the initial polymerization of epichlorohydrin followed by amination with diethyl-amine. Cotton fibre treated with the polymer (6∼8% o.w.f.) is highly cationic and exhibit increased substantivity for anionic dyes. The modified substrate could be dyed with direct dyes without salt or a little salt from dye bath. The increased concentration of cationic agents resulted in an increase the colour yield. Futhermore, treated cotton has an electropositive surface charge. Adsorption of direct dye can be attributed to both van der waals force and electrostatic attraction.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.301-308
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• 2015

This study optimizes dyeing conditions for polyamide-imide fabric using cationic dyes. Dyeing and fastness characteristics of polyamide-imide fabric were investigated with three cationic dyes and 2-hydroxyacetophenone as a swelling agent under various dyeing conditions such as dye and swelling agent concentrations, dyeing temperature and time, pH of dye bath. The dyeing properties were evaluated in terms of dye exhaustion, K/S value and color fastness. The optimized dyeing temperature and time were $130^{\circ}C$ for 90 min for the dyes. Under weak acidic conditions in the range pH 5 to 7, the exhaustion of cationic dyes could be enhanced leading to higher adsorption. Wash and rubbing fastness properties were generally good, while light fastness was slightly low, which can be attributed to the poor photo-stability of the cationic dyes.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.577-585
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• 2001

Dyeing properties of the colorants extracted from pomegranate hull on cotton fabric were investigated. Effects of dyeing conditions and mordanting on dye uptake, color change and colorfastness were explored. Cationic agent treatment was done for cotton to improve low dyeability in natural dyeing. In addition antimicrobial activity of the cotton fabrics dyed with pomegranate colorants was examined by the shake flask method. Pomegranate colorants showed low affinity to cotton fiber and its adsorption isotherm was Freundlich type. Therefore, hydrogen bonding was involved in the adsorption of pomegranate colorants onto cotton fiber. Mordants did not significantly increase dye adsorption. Pomegranate colorants produced mainly yellow color on cotton fabric. In order to improve dye uptake, cotton was cationized by treating with Cationon UK(quarterly ammonium salt) and chitosan. The cationized cotton with Cationon UK showed higher dye uptake and shorter dyeing time, compared with the untreated cotton. Chitosan treated cotton also showed high dye uptake, but chitosan was less effective compared with Cationon UK. Fastness to washing, perspiration, and rubbing was not improved by mordanting and cationizing treatment, but light fastness was increased by all mordants and cationic agent. As dye concentration increased, bacterial reduction rate was increased and mordants did not significantly increase bacterial reduction rate.

• Textile Coloration and Finishing
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• v.6 no.4
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• pp.46-53
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• 1994

Polymer cationic agent was prepared by the initial polymerisation of epichlorohydrin followed by amination with diethylamine. Cotton fibre treated with the polymer (6~8% o.w.f.) is highly cationic and exhibit increased substantivity for reactive dyes under neutral to weakly acid conditions. The modified substrate could be dyed with reactive dyes without salt or a little salt from dye bath. The increased concentration of cationic agents resulted in an increase the colour yield. Futhermore, treated cotton has an electropositive surface charge. Adsorption of Reactive dye can be attributed to both van der waals force and electrostatic attraction.

• Membrane and Water Treatment
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• v.10 no.2
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• pp.139-148
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• 2019

In this study, the removal of MB from saline solutions was evaluated by two methods by adsorption and electrodialysis; the adsorption of the mixture dye/salt on dried orange peel waste (OPW) was studied in batch method. In this study the biosorption of cationic dye by OPW was investigated as a function of initial solution pH, and initial salt (sodium chloride) concentration. The maximal dye uptake at $pH{\geq}3.6$ in the absence and in the presence of salt and the dye uptake diminished considerably in the presence of increasing concentrations of salt up to 8 g/L. The Redlich Peterson and Langmuir were the most suitable adsorption models for describing the biosorption equilibrium data of the dye both individually and in salt containing medium. As well, this work deals with the electrodialysis application to remove the dye. Synthetic solutions were used for the investigation of the main operational factors affecting the treatment performance; such as applied voltage, pH, initial dye concentration and ionic strength. The experimental results for adsorption and electrodialysis confirmed the importance of electrostatic interactions on the dye. The electrodialysis process with standard ion exchange membranes enabled efficient desalination of cationic dye solutions; there are two main factors in fouling: electrostatic interaction between cations of dyes and the fixed charged groups of the CEM, and affinity interactions.