Additive effects on cotton dyeing with dye extract from achiote seeds

466-474Cotton yarns have been pretreated with the additives, such as chitosan, microcrystalline chitosan, quaternized chitosan & aqueous extract from the fruit of Diospyros mollis Griff, as well as with the commercial formaldehyde-free cationic fixing agent (Sera® Fast C-NC) & alum (post-mordanting), and their dyeing fastness properties are studied. These treated cotton yarns are then dyed with the annatto dye extract from Bixa orellana L. (Achiote) seeds and tested for different properties including K/S value, light fastness, and wash fastness. Pre-treatment of cotton yarn with chitosan or microcrystalline chitosan solution (together with glyoxal cross-linking) or quaternized chitosan, or Sera® Fast C-NC before dyeing, shows a better color depth (K/S) and improved wash fastness properties in comparison to yarn with alum post-mordanting and the untreated cotton yarn. Improved light fastness is also obtained on inclusion of the anti-oxidant ascorbic acid in the post-treatment protocol. These additive treatments thus offer considerable potential for the improved annatto dyeing of cotton

Additive effects on cotton dyeing with dye extract from achiote seeds

Cotton yarns have been pretreated with the additives, such as chitosan, microcrystalline chitosan, quaternized chitosan &aqueous extract from the fruit of Diospyros mollis Griff, as well as with the commercial formaldehyde-free cationic fixingagent (Sera® Fast C-NC) & alum (post-mordanting), and their dyeing fastness properties are studied. These treated cottonyarns are then dyed with the annatto dye extract from Bixa orellana L. (Achiote) seeds and tested for different propertiesincluding K/S value, light fastness, and wash fastness. Pre-treatment of cotton yarn with chitosan or microcrystallinechitosan solution (together with glyoxal cross-linking) or quaternized chitosan, or Sera® Fast C-NC before dyeing, shows abetter color depth (K/S) and improved wash fastness properties in comparison to yarn with alum post-mordanting and theuntreated cotton yarn. Improved light fastness is also obtained on inclusion of the anti-oxidant ascorbic acid in the posttreatmentprotocol. These additive treatments thus offer considerable potential for the improved annatto dyeing of cotton

Additive effects on cotton dyeing with dye extract from achiote seeds

2019, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved. Cotton yarns have been pretreated with the additives, such as chitosan, microcrystalline chitosan, quaternized chitosan & aqueous extract from the fruit of Diospyros mollis Griff, as well as with the commercial formaldehyde-free cationic fixing agent (Sera® Fast C-NC) & alum (post-mordanting), and their dyeing fastness properties are studied. These treated cotton yarns are then dyed with the annatto dye extract from Bixa orellana L. (Achiote) seeds and tested for different properties including K/S value, light fastness, and wash fastness. Pre-treatment of cotton yarn with chitosan or microcrystalline chitosan solution (together with glyoxal cross-linking) or quaternized chitosan, or Sera® Fast C-NC before dyeing, shows a better color depth (K/S) and improved wash fastness properties in comparison to yarn with alum post-mordanting and the untreated cotton yarn. Improved light fastness is also obtained on inclusion of the anti-oxidant ascorbic acid in the post-treatment protocol. These additive treatments thus offer considerable potential for the improved annatto dyeing of cotton

A kinetic and thermodynamic study of lac dye adsorption on silk yarn coated with microcrystalline chitosan

The coating of silk yarn with microcrystalline chitosan (MCCh) was carried out using the ultrasonic-assisted method at a pulsed wave frequency of 80 kHz, which only had a slight impact on the yarn as measured by changes in Young\u27s modulus and percentage of elongation compared with untreated silk. A significant enhancement of lac dye uptake onto MCCh-coated silk yarn compared with the untreated silk was observed. The rate of dye uptake at different temperatures onto silk yarn coated with MCCh was investigated. It was found that the adsorption rate constant and diffusion coefficient both increased with increasing temperature, as a result of a diffusion kinetically controlled process with a diffusion activation energy of 9.40 kJ mol −1 . This suggests that dye adsorption on silk yarn coated with MCCh is a physisorption process. The free energy change (∆G ○ ), enthalpy change (∆H ○ ) and entropy change for dye adsorption were also determined, and the negative values of ∆G ○ and ∆H ○ obtained indicated that the lac dye adsorption process is both spontaneous and exothermic

Synthesis and Fluorescence Properties of N‑Substituted 1‑Cyanobenz[<i>f</i>]isoindole Chitosan Polymers and Nanoparticles for Live Cell Imaging

Highly fluorescent N-substituted 1-cyanobenz­[<i>f</i>]­isoindole chitosans (CBI-CSs) with various degrees of N-substitution (DS) were synthesized by reacting chitosan (CS) with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide under mild acidic conditions. Introduction of 1-cyanobenz­[<i>f</i>]­isoindole moieties into the CS backbone resulted in lowering of polymer thermal stability and crystallinity. The fluorescence quantum yield (Φ_f) of CBI-CS was found to be DS- and molecular-weight-dependent, with Φ_f decreasing as DS and molecular weight were increased. At similar DS values, CBI-CS exhibited 26 times higher Φ_f in comparison with fluorescein isothiocyanate-substituted chitosan (FITC-CS). CBI-CS/TPP nanoparticles were fabricated using an ionotropic gelation method in which pentasodium triphosphate (TPP) acted as a cross-linking agent. CS and CBI-CS exhibited low cytotoxicity to normal skin fibroblast cells over a concentration range of 0.1–1000 μg/mL, while an increased cytotoxicity level was evident in CBI-CS/TPP nanoparticles at concentrations greater than 100 μg/mL. In contrast with CBI-CS polymers, the CBI-CS/TPP nanoparticles exhibited lower fluorescence; however, confocal microscopy results showed that living normal skin fibroblast cells became fluorescent on nanoparticle uptake. These results suggest that CBI-CS and fabricated nanoparticles thereof may be promising fluorescence probes for live cell imaging