Oxidation Of Wool Research Articles

Facile development of electrically conductive comfortable fabrics using metal ions

Development of conductive fabrics causes usually deterioration of the some of the comfort attributes of the final textile product. In this work, we propose a simple non-deteriorative method for preparation of electrical conductive fabrics based on wool and polyester as well as the blended fabric thereof. The unmodified fabrics or saponified polyester or oxidized wool were treated in aqueous solution containing heavy metal ion salts, namely, silver nitrate, copper II sulfate using exhaustion technique at 70°C for 1 h followed by reduction step. Nano zinc oxide was also used directly for treatment on the said fabrics. The electrical conductivity of the metal ions-treated fabrics and the influence of sewing on their conductivity was measured. The effect of pretreatment of the fabrics, saponification of polyester or oxidation of wool on their ability to absorb metal ions was monitored. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to prove the incorporation of metal particles onto the treated fabrics. The change in chemical composition of the treated fabrics was studied using Fourier transform infrared spectroscopy. Atomic absorption was adopted to measure the amount of metal incorporated onto the treated fabrics. The formation of nanometal crystals was proved using X-ray diffraction pattern. Different parameters of comfort, namely, air/water permeability of the treated as well as untreated fabrics were assessed. The treated fabrics exhibit enhanced electrical conductivity as well as some improved comfort properties without any effect on their inherent mechanical properties.

Characterizing Wool Keratin

Keratin from wool is a reactive, biocompatible, and biodegradable material. As the biological structural component of skin (soft keratins) and of nails, claws, hair, horn, feathers, and scales (hard keratins) pure keratin comprises up to 90% by weight of wool. Wool was treated in alkaline solutions to extract from 68% to 82% keratin within 2 to 5 hours of exposure at 65∘C. The keratin products were water‐soluble and were confirmed to contain intermediate filament and microfibrillar component‐proteins of fractured, residual cuticle, and cortical cells. Oxidation of wool by peroxycarboximidic acid in alkaline hydrogen peroxide produced keratin products with distinct microcrystalline structures: descaled fibers, fibrous matrices, and lyophilized powders. Morphology and confirmation of peptide functionality were documented by SEM, Amino Acid Analysis, SDS‐PAGE gel electrophoresis, MALDI‐TOF/TOF, and FTIR analyses. The reactivity of keratin from wool models the reactivity of keratin from low‐value sources such as cattle hair.

Adsorption of Amino-Functional Polymer Particles onto Keratin Fibres

The adsorption behavior of cationic polymer particles onto wool fibers has been investigated in this study. In particular, the role of the lipid layer surrounding the wool fibers and the oxidation of wool has been studied in terms of polymer adsorption. For this, polymer particles consisting of cross-linked polystyrene cores and containing surface ammonium chloride groups have been synthesized. These colloidal particles are solely stabilized through electrostatic repulsion. It was shown that, under the same conditions, no polymer particles are adsorbed onto untreated wool while a monolayer is adsorbed onto wool of which the lipid layer has been removed. Wool oxidized with peroxomonosulfuric acid displays a very similar behavior in terms of wetting characteristics and polymer adsorption to untreated wool, despite an increased amount of cysteic acid on the fiber surface. X-ray photoelectron spectroscopy results indicate that the lipid layer is still intact after this oxidative treatment. A monolayer of polymer particles can be observed on the wool surface after the removal of the lipid layer. The enhanced adsorption of polymer particles onto untreated and oxidized wool from which the lipid layer has been removed indicates that this layer presents a major adsorption barrier for cationic polymer particles.

Reaction of Wool with Permonosulfate and Related Oxidants

As part of a program directed at zero-AOX shrinkproofing treatments, we have compared the reactivity of different oxidants with wool by following their disappearance under similar conditions. The reactivity series was as follows: aqueous chlorine > DCCA ~ permonosulfate > permanganate / salt > peracetic acid > permanganate > persulfate ~ hydrogen peroxide. This series was not related to redox potentials but generally followed the level of shrink resistance imparted by the oxidant. Fourier transform infrared spectroscopy using the attenuated total reflectance technique showed significant differences in the amounts of cystine oxidation products formed in the oxidations above. One new finding was the direct formation of low concentrations of Bunte salts by the oxidation of wool with persulfate. We further studied the surface of permonosulfate-treated fibers with scanning electron microscopy and frictional measurements. Permonosulfate treated wool fibers produce Allwörden sacs with chlo rine water, whereas aqueous chlorinated fibers do not. We suggest that the most likely mechanism for shrink resistance in permonosulfate treatments is the removal of de graded protein from below the exocuticle, producing a modified surface with a reduced differential friction between the "for" and "against" scale directions.

Ce iv initiated graft polymerization of methyl methacrylate on wool fibres

Grafting of MMA on wool and modified wool fibres (viz reduced, KCN-treated, acetylated, alkylated and dinitrophenylated wool) was studied using the ceric ion technique. With the exception of KCN-treated wool, grafting was accompanied by formation of a substantial amount of homopolymer depending on the concentrations of initiator and monomer, reaction time and temperature. Homopolymerization of MMA in the presence of wool exceeded its polymerization in the absence of wool, probably because of initiation by free radicals formed at reactive sites in the wool. Except in a few cases, ceric consumption during oxidation of wool was found to be higher than that during grafting, suggesting that termination of the growing grafted polymer chains occurred by a mechanism not involving ceric. A reaction mechanism is proposed for grafting of MMA on wool in this system.

Studies in chrome mordanting. III. The oxidation of wool by chromium(VI)

The effect of boiling wool in a chromium(VI) solution on the groups present in wool has been investigated. At low pH the disulphide bonds were oxidized directly, whereasat high pH the hydrolysis products of the disulphide bonds, such as hydrogen sulphide, rather than the disulphide bonds themselves were oxidized. In addition, tyrosine was oxidized throughout the pH range investigated (pH 2-9) and lysine was oxidized at high pH (pH 7-9), though not at low pH. The maximum chromium(III) uptake by the wool, for a given concentration of chromium(VI) in the bath, occurred at pH 4.

Studies on Oxidised Wool. I. A Comparison of the Completeness of Oxidation With Peracetic and Performic Acid

The oxidation of wool with performic and peracetic acids has been compared by measuring the cysteic acid contents of hydrolysates of the oxidized wool. Whereas virtually complete oxidation takes place with performic acid, the oxidation with peracetic acid is incomplete. Performic acid can also further oxidize the partial oxidation products in wool treated with peracetic acid and it is concluded that performic acid is the more powerful oxidizing agent for wool. For the oxidation of the disulphide bonds prior to the extraction of proteins from wool, performic acid is therefore the better reagent.

The Oxidation of Wool by Inorganic Peracids

The Oxidation of Wool by Inorganic Peracids

Oxidation of wool: Alkali-solubility test for determining the extent of oxidation

Oxidation of wool: Alkali-solubility test for determining the extent of oxidation

Oxidation of wool: Photochemical oxidation

Oxidation of wool: Photochemical oxidation

Oxidation of wool: effect of hydrogen peroxide on wool

Oxidation of wool: effect of hydrogen peroxide on wool

Oxidation of wool: the lead acetate test for hydrogen peroxide bleached wool

Oxidation of wool: the lead acetate test for hydrogen peroxide bleached wool

LVII. Products of the oxidation of wool. Cyano-propionic acid

LVII. <i>Products of the oxidation of wool. Cyano-propionic acid</i>