Organoclay-assisted disperse dyeing of polypropylene nanocomposite fabrics in supercritical carbon dioxide.

Dyeing using supercritical carbon dioxide (SC-CO2) is carried out on the polypropylene (PP) nanocomposite fabrics with model disperse dye compared with their regular fabric at various dyeing temperatures and pressures. The results are compared with those obtained in aqueous dyeing method. The PP nanocompsite fabrics dyed in SC-CO2 medium exhibited higher colour strength (K/S) values compared with their PP regular fabric. The PP nanocompsite fabrics and their regular fabric dyed in SC-CO2 medium have higher K/S values than those dyed in aqueous medium. The color coordinates of all PP fabrics dyed in SC-CO2 and aqueous medium were positive with respect to a* and b* coordinates depending on the disperse red dye uptake. The PP nanocomposite fabrics dyed in SC-CO2 and aqueous medium exhibited higher antibacterial properties than their regular fabrics. All PP fabrics dyed in SC-CO2 and aqueous medium present very good washing, perspiration and light fastness.

Key features of blend denim fabrics performance with dyed weft silk yarn and different weave structures.

This research aimed to weave the warp indigo-dyed cotton yarn with un-dyed or dyed silk yarn and analyze the impact of different weft yarn structures on the properties of denim fabrics. The dyed silk yarn was performed by a selection of different anionic indigo and non-indigo blue dyestuffs. The dyeing shades of the anionic Indigo Carmine dye on silk exhibited high build-up at the acidic pH range 2-2.5 with poor washing fastness and even so, the cationic aftertreatment of the dyed silk samples showed un-matched color with indigo-dyed cotton yarns. The dyeing properties of two commercial non-indigo reactive and acid dyes on silk add other advantages. To ascertain the dyeing shades evaluation of the non-indigo dyes on silk, two sets of blended denim fabrics were investigated. The first set included a weft-wise silk yarn dyed with reactive dye RB 5, and the second set included silk yarns dyed with acid dye AB 193. Weaving of the blended fabrics was carried out in Twill 3/1, 3/2 Z,and Satin 53 patterns and exhibited significant color effects of the dyed silk yarns to those of the un-dyed control samples. The dyeing shades of the non-indigo RB 5 and AB 193 dyed weft-wise silk yarns were found to be matched in color performance with the conventionally indigo- dyed cotton yarns. Ultraviolet resistance of the blend denim fabrics was evaluated, showing significant improvement in UPF of the weft-wise dyed silk. The study claimed that the dyed silk yarns a good candidate for newly developed blend denim fabrics.

Eco-friendly salt/alkali-free exhaustion dyeing of cotton fabric with reactive dyes.

The textile-wet process enormously consumes a large volume of water and chemicals, and thus awareness of cleaner production has been growing to protect the environment from the industrial effluents. In this context, reactive dyeing of cellulosic materials such as cotton fabrics is a major sector of textile coloration that necessitates the use of a large amount of sodium sulfate or sodium chloride and alkali to exhaust and fix the dye molecules with cellulosic macromolecules, respectively. However, the remaining salt and alkali in the effluent badly affect the environment. For this purpose, the use of trisodium nitrilotriacetate (TNA) in reactive dyeing of cotton fabrics was hypothesized to have a double benefit, one as an exhausting agent (organic salt) and the second as a fixing agent (organic base). Thus, the exhaust dyeing characteristics of cotton fabrics using C.I. Reactive Yellow 145 (RY145) was optimized under different conditions of TNA concentration, alkali concentration, temperature, and dyeing time. The color strength and the primary and secondary exhaustion values were also investigated with an eye on those values obtained using the conventional dyeing method. The characterization of effluent samples with RY 145 taken after dyeing using TNA compared with conventional dyeing indicated an efficient reduction of COD, BOD, and TDS values by 99, 97, and 97%, respectively. The new dyeing method was implemented using C.I. Reactive Black 5 (RB5), C.I. Reactive Blue 160 (RB160), and C.I. Reactive Red 24 (RR24) to reveal good dyeability and fastness properties comparable with those obtained using the conventional method. The overall results obtained suggest the suitability of TNA as an environmentally friendly agent suitable as an exhausting and fixing agent of cellulosic fabrics.

A local Talaromyces atroroseus TRP-NRC isolate: isolation, genetic improvement, and biotechnological approach combined with LC/HRESI-MS characterization, skin safety, and wool fabric dyeing ability of the produced red pigment mixture.

BACKGROUND: During the last decade, enormous research efforts have been directed at identifying potent microorganisms as sustainable green cell factories for eco-friendly pigments. Talaromyces atroroseus has recently been shown to excrete large amounts of azaphilone mycotoxin-free red pigment mixture comprising some known coloring components together with many uncharacterized metabolites. In this study, a new Talaromyces atroroseus isolate was identified via sequencing of the fragment of the nuclear ribosomal gene cluster containing internal transcribed spacers and 5.8S rRNA gene. The parameters that affected the level of pigment production were optimized in uncommon static conditions of culture and genetic improvement, via γ-irradiation, to improve pigment yield. Moreover, chemical characterization using LC/MS and skin safety test of the target pigment mixture were precisely conducted to maximize its benefits as a natural and safe red pigment for wool fabrics. RESULTS: Molecular identification via the sequencing of the ITS of the rDNA encoding gene cluster revealed that the fungal isolate TRP-NRC was T. atroroseus TRP-NRC (deposited in GenBank under accession number MW282329). In the static conditions of culture, pigment production was dramatically enhanced to 27.36 g/L in an optimum yeast malt peptone medium of 2% mannitol at pH 2-4.5 and 30 °C for 7 days of incubation. Under exposure to a 400-Gy γ-radiation dose, pigment yield was increased to a 3-fold level higher than that recorded for the wild type. Based on the inter-simple sequence repeats (ISSR), as a molecular marker tool, the wild-type T. atroroseus TRP-NRC strain and its mutants were discriminated. The UHPLC/HRESI-MS analytical tool characterized 60 metabolites, including many unknown molecules, at appropriate concentrations. It is worthy to note that four mitorubrin derivatives were identified for the first time in T. atroroseus, i.e., mitorubrinolamine acetate, dihydro-PP-O, mitorobrinal, and mitorubrinol. The range of irritation indexes (0-0.1) demonstrated an adequate skin safety after the direct local application of the pigment mixture. Finally, the pigment mixture exhibited a remarkably good dyeing ability in wool fabrics, with high-fastness properties. CONCLUSIONS: Because of its sustainable and economic production, the target red pigment mixture may be applied in the future in textile, food, cosmetics, or different pharmaceutical industries after extensive conventional safety and toxicity studies, which are currently under consideration.

Synthesis and spectral properties of new fluorescent hydrazone disperse dyes and their dyeing application on polyester fabrics.

A new series of solid state fluorescent disperse dyes based on hybrid structure of pyrrolinone ester (PES)/coumarin moiety was prepared and fully characterized using spectroscopic analysis such as 1HNMR, MS and IR spectra. The coumarin derivative (7- amino-4- methyl coumarin) was initially prepared from amino phenol via multi steps condensation reactions and its diazonium salt coupled with the pyrrolinone ester to form the hydrazone dyes. 1HNMR data of the prepared dyes exhibited a pure hydrazone form as a mixture of E, Z isomers. These dyes showing a significant emission in solid state as well as on the dyed fabric. The dyeing application on polyester fabrics was investigated which showing that these dyes show high affinity to polyester fabric, and minor change in the dye affinity by changing pH even under alkaline conditions was observed.