Eforia Tsatsaroni

Effect of enzymatic treatment on the dyeing of cotton and wool fibres with natural dyes

Cotton and wool fabrics were dyed with the natural dyes chlorophyll and carmine after treatment with the enzymes cellulase, α-amylase and trypsin. Wash and light fastnesses of the dyed samples were studied. Enzymatic pretreatment resulted in an increase in pigment uptake in all cases compared with the corresponding untreated samples, and did not affect fastness properties. Pretreatment with metallic salts and dyeing of pretreated samples was also carried out and the fastness properties of the dyed materials were studied. The effect of conventional mordanting with metallic salts was compared with that of enzymatic treatment on the dyeing properties of the dyes used.

Comparative study of dyeing properties of two yellow natural pigments : Effect of enzymes and proteins

The crude water extract of saffron stigmas (Crocus sativus L.) as well as crocin, the yellow pigment isolated from Crocus sativus L. were used for dyeing cotton and wool fibres after enzymatic treatment. The dyeing results were compared with those obtained with another yellow natural pigment, curcumin. Wash and light fastness of all dyed samples were studied. The enzymes used were α-amylase, amyloglycosidase and trypsin for the cotton and wool samples respectively. In addition, casein was used in the case of curcumin as a pretreating agent and its effect on the dyeing properties of the pigment was studied.

Dyeing of cotton and wool fibres with pigments from Crocus sativus—Effect of enzymatic treatment

Natural pigments from Crocus sativus stigmas were used for the dyeing of cotton and wool fibres after treatment with the enzymes α-amylase and trypsin, respectively. The separation of various compounds and pigment constituents of the stigmas was effected by fractionation of the methanolic extract on a silica gel column, and the use of these fractions for dyeing is described. The dyeing properties of the fractions were compared with those of commercial trans-β-carotene. Wash and light fastness of the dyed samples after the enzymatic pretreatment were also studied.

Disperse ink-jet inks with active agents: properties and application to polyester and polyamide fibers

The preparation of water-based disperse inks was made using water and a mixture of 2-propanol/ethylene glycol as the water-miscible solvent. Ethylene glycol acted also as a wetting agent. The surface tension, pH, viscosity and conductivity of the above formulations were monitored over a period of 360 days. The same inks were prepared by adding solutions of 0.5, 1.0 and 2.0% w/v of fragrance microcapsules, as well as the same concentrations of an antimicrobial agent dispersion as active additives, and the properties were monitored over 360 days. The compatibility of the two additives with the ink ingredients, as well as the suitability of the final inks for ink-jet printing, was confirmed by these measurements. The inks were used (i) for dyeing polyester and polyamide samples and (ii) for ink-jet printing on paper, transfer printing on polyester and thermostabilization. Wash and light fastness were evaluated on the dyed and printed samples according to BS 1006:1990 CO2 and BO2, respectively, and they were found to be very good to excellent for polyester samples, and medium for polyamide samples. Color measurements of the dyed and printed polyamide and polyester samples were made and the results confirmed the high affinity of the two disperse dyes to the non-polar polyester fiber compared to the polyamide fiber. Qualitative and quantitative determination of the agents adsorbed on the dyed and printed polyester samples was made by gas chromatography-mass spectroscopy or spectrophotometrically.

Effect of enzymatic treatment on the dyeing properties of protein wool fibers

Two proteolytic enzymes were used as auxiliaries in the dyeing of wool fabrics with acid dyes. The effect of the enzymes on dye exhaustion (%E) and dye uptake (K/S) was studied at 70, 85, and 98 °C and compared to the corresponding values obtained for the control samples which were dyed without enzymes under the same conditions. Two commercially available dyeing auxiliaries commonly used for the dyeing of wool at low temperatures were also used under the same conditions and compared with the dyeings made with and without enzymes. Treatment with transglutaminase was done in order to compensate the damaging effects of protease. The study shows that the enzymes could be used as auxiliaries in the dyeing of wool at lower temperatures.

Disperse inkjet inks with a new antibacterial agent as additive: Properties and application to polyester and polyamide fibres

Two water based disperse inkjet inks for polyester textile printing with antibacterial properties were prepared. The antibacterial activity was due to the presence of polyhexamethylene bisguanidine (PHMBG). The surface tension, pH, viscosity and conductivity of all inks formulations were monitored over a period of time for the evaluation of ink stability and suitability. The inks were used for application on polyester and polyamide samples by exhaustion (dyeing) and wash, light fastness and colour measurements were made on the dyed samples. The optimum application level required to give long lasting antimicrobial protection was determined by carrying out a series of antimicrobial testing.

A novel synthesis, characterization and application of Fe and Co anionic metal complex azo dyes based on environmental considerations

The synthesis and characterization of a novel Fe-complex as a substitute for the Cr-complex and Co-complex acid azo dyes was carried out and the subsequent use of ultra-filtration was studied with the aim of purifying the metal complex dyes and thus increasing dye strength and solubility and additionally reducing the free heavy metal present in the final dye. A drastic reduction in the content of inorganic additives and free metal was achieved by the ultra-filtration process. The ultra-filtrated and non-ultra-filtrated dyes were used to dye wool and nylon fabric. Colour measurements and fastness properties were performed on the dyeings made on wool and nylon and compared with the Cr-complex dyeings thus examining the possibility of using successfully the Fe-complex dye as possible replacement of the Cr- and Co-complex dyes. The synthesis of the Fe-complex dye combined with the implementation of ultra-filtration technology results in producing a more environmentally friendly innovative dye with greatly improved purity and solubility.

Identification and Quantitative Determination of Madder by High Performance Liquid Chromatography: Application to Historical Textiles

Abstract A reversed phase HPLC method has been developed for the identification and quantification of madder applied to an old textile. An isocratic method was used for the identification of alizarin and purpurin, the main pigments in the madder plant, which were identified and quantified in cotton and wool reference samples and in the unknown textile. FTIR-spectroscopy was also used for the identification of pigment and fiber of the unknown sample.

Azo reactive dyes: ultrafiltration and application to cotton by exhaustion and digital ink-jet printing

Three reactive dyes have been synthesized by coupling 1-amino-phenyl-4-beta hydroxyethyl sulfone sulfate ester with 1-amino-8-hydroxynaphalene-3,6-disoulphonic acid (H-acid). The dyes synthesized were then purified using ultrafiltration and water-based reactive ink jet inks were prepared for digital printing applications. The dyes were characterized by their spectrophotometrical data ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy, optical emission spectroscopy, X-ray diffraction and elemental analysis. The purity of dyes was checked by thin layer chromatography and their dyeing performance was assessed on cotton fibers by exhaustion (dyeing) and ink-jet printing. Ink-jet inks with the dyes synthesized were prepared and their physical properties were measured in order to evaluate their suitability for ink-jet printing. Color measurements and fastness properties were performed for the dyed and digitally printed samples. Coloristic values of the dyed/ printed samples were as expected, that is, K/S values of the dyed samples were much higher than those of the printed ones, K/S values of the samples dyed with the ultrafiltrated dyes were higher than those with the initial dyes and the rest of the coloristic co-ordinates L, a, b, C, H, were in line with strength changes of the dyes before and after ultrafiltration. The dyed samples had excellent wash fastness and medium light fastness. Ultrafiltration slightly improves the fastness properties of the dyed samples.

Synthesis, characterization and ultrafiltration of reactive dyes. Application by exhaustion and/or ink-jet printing—II:

Three novel vinyl sulfone reactive dyes of various metallic salts (Na, K, Li) have been synthesized by coupling 1-amino-phenyl-4-beta hydroxyethyl sulfone sulfate ester with 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid (H-acid). The reactive dyes were then purified using ultrafiltration (UF). The ultrafiltrated dyes of the various metallic salts were characterized by their spectrophotometrical data using Ultra Violet-visible (UV-vis), Fourier transform infra-red and optical emission spectroscopy, X-ray diffraction, and elemental analysis. The purity of the dyes was checked by Thin Layer Chromatography (TLC). The solubility characteristics of the various salts of the ultrafiltrated reactive dyes were assessed and compared with the non-ultrafiltrated reactive dyes of the same salts. The dyes were characterized and applied to cotton, wool, and nylon 66 by exhaustion (dyeing). Novel water-based reactive ink-jet inks were prepared with the ultrafiltrated reactive dyes of the various metallic salts. Their suitability for digital printing applications was examined by using a digital printer on suitably pretreated cotton samples. Color and fastness properties measurements were performed for both the dyed and digitally printed samples. K/S values of the dyed samples were higher than those of the digitally printed ones, whereas K/S values of the samples dyed with the ultrafiltrated dyes were much higher than those of the non-ultrafiltrated dyes. The other coloristic co-ordinates L*, a*, b*, C*, and ho were in line with strength changes of the dyes before and after UF. The dyed and digitally printed samples had excellent wash and good light fastness properties. UF slightly improved the fastness properties of the dyed samples.