Cuticle modifications and dyeing property of ultrasonically scoured wool

Ultrasonics has the potential to reduce the cost and environmental impact of textile processing. This work investigates the effects of utrasonic irradiation during wool scouring on fibre surface properties and fibre dyeing rate. A range of ultrasonic frequencies were used in the scouring bath to examine the forms of fibre cuticle damage. It was shown that ultrasonically scoured wool underwent some modifications of the fibre surface structure which resulted in a higher rate of dye uptake by the fibres, when compared with the conventionally scoured wool. The lower the ultrasonic frequency the more sever was the cuticle damage to wool during scouring, hence the higher the fibre dye uptake.

Confocal laser scanning microscopy elucidation of the micromorphology of the leaf cuticle and analysis of its chemical composition

Electron microscopy techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been invaluable tools for the study of the micromorphology of plant cuticles. However, for electron microscopy, the preparation techniques required may invariably introduce artefacts in cuticle preservation. Further, there are a limited number of methods available for quantifying the image data obtained through electron microscopy. Therefore, in this study, optical microscopy techniques were coupled with staining procedures and, along with SEM were used to qualitatively and quantitatively assess the ultrastructure of plant leaf cuticles. Leaf cryosections of Triticum aestivum (wheat), Zea mays (maize), and Lupinus angustifolius (lupin) were stained with either fat-soluble azo stain Sudan IV or fluorescent, diarylmethane Auramine O and were observed under confocal laser scanning microscope (CLSM). For all the plant species tested, the cuticle on the leaf surfaces could be clearly resolved in many cases into cuticular proper (CP), external cuticular layer (ECL), and internal cuticular layer (ICL). Novel image data analysis procedures for quantifying the epicuticular wax micromorphology were developed, and epicuticular waxes of L. angustifolius were described here for the first time. Together, application of a multifaceted approach involving the use of a range of techniques to study the plant cuticle has led to a better understanding of cuticular structure and provides new insights into leaf surface architecture.

Rapid and effective cuticle removal from wool fibers using ionic liquid

Wool fibers are composed of cuticle and cortex cells, which are of obvious differences in many properties. The development of methods to isolate the two kinds of cells can provide platform to elucidate the roles they play in the characteristics of wool fibers. Here we demonstrate the cuticle can be completely and rapidly removed from the wool fibers by the use of ionic liquids, with inner cortex intact. Confocal microscope, SEM and FTIR have been applied to study the wool fibers after cuticle removal. In contrast to the traditional/long physical or chemical separation routes (>14 h), our method is very rapid (<1 h). This work demonstrates the ability of ionic liquid as a novel, rapid and efficient media for cuticle/ cortex isolation.

Cashmere and wool cortical cells

This paper proposes that instead of the expensive and difficult task of examining the morphology of fibre cuticle scales that an alternative approach of examining the internal morphology of cortical cells may be faster and cheaper. Preliminary data were presented and further work is required.

Effects of atmospheric pressure plasma on dye uptake by the surface of wool

A woven pure wool fabric has been exposed to atmospheric pressure plasma for 30 seconds using a pilot-scale. commercial machine. X-ray photoelectron spectral data revealed large increases in oxygen and nitrogen. and a large reduction in carbon. on the surfaces of the plasma-treated fibres. A CIN ratio of 3.55 for plasma-treated wool was consistent with removal of the covalently-bound fatty acids from the surface of the cuticle cells. resulting in exposure of the proteinaceous epicuticle. Dye staining experiments revealed that the back of the fabric had received the same, uniform level of treatment as the face, despite the fact that only the face had been directly exposed to the plasma. Dyes (1 % oww) were applied to fabric at 50°C (liquor ratio =40: 1) and pH values from 3 to 6. The relatively low temperature of 50°C was selected in order to accentuate the effects of plasma on the rate of dye uptake. Under these conditions, dye was adsOibed onto the fibre surfaces, with very little penetration into the fibres. Effects of the plasma treatment on the rate of dyes adsorption were dyespecific. No significant effects of plasma on the rate of dye uptake were observed with relatively hydrophobic dyes, but hydrophilic dyes were adsorbed more rapidly by the plasmatreated fabric. It would appear that for more hydrophobic dyes, hydrophobic effects are more important for the adsorption of dyes by the plasma-treated fibres, even though these fibres were quite hydrophilic. On the other hand. it is concluded that for more hydrophilic dyes, electrostatic effects are more important for adsorption by the plasma-treated fibre.

A morphology-related study on photodegradation of protein fibres

The wool fibre has a complex morphology, consisting of an outer layer of cuticle scales surrounding an inner cortex. These two components are hard to separate effectively except by using harsh chemical treatments, making it difficult to determine the susceptibility of the different components of the fibre to photoyellowing. An approach to this problem based on mechanical fibre modification is described. To expose the inner cortex of wool to different degrees, clean wool fibres were converted into ‘powders’ of various fineness via mechanical chopping, air-jet milling, ball milling or their combination. Four types of powdered wool (samples A, B, C and D) were produced with reducing particle size distributions and an increasing level of surface damage as observed using SEM. Sample A contained essentially intact short fibre snippets and sample D contained a large amount of exposed cortical materials. Samples B and C contained a mixture of short fibre snippets and cortical materials. Solid wool discs were then compressed from the corresponding powder samples in a polished stainless steel die to enable colour measurement and UV irradiation studies. ATR-FTIR studies on powder discs demonstrated a small shift in the amide I band from 1644 cm−1 for disc A to 1654 cm−1 for disc D due to the different structures of the wool cuticle and cortex, in agreement with previous studies. Similarly an increase in the intensity ratio of the amide I to amide II band (1540 cm−1) was observed for disc D, which contains a higher fraction of cortical material at the surface of the disc.

Discs prepared from sample D appeared the lightest in colour before exposure and had the slowest photoyellowing rate, whereas discs made from powders A–C with a higher level of cuticle coverage were more yellow before exposure and experienced a faster rate of photoyellowing. This suggests that the yellow chromophores of wool may be more prevalent in cuticle scales, and that wool photoyellowing occurs to a greater extent in the cuticle than in the cortex. Photo-induced chemiluminescence measurements showed that sample D had a higher chemiluminescence intensity after exposure to UVA radiation and a faster decay rate than samples A and B. Thus one of the roles of the wool cuticle may be to protect the cortex by quenching of free radical oxidation during exposure to the UV wavelengths present in sunlight.

Frequency dependence of ultrasonic wool scouring

Conventional aqueous scouring of greasy wool promotes wool felting and can be energy and water intensive. Ultrasonic wool scouring could be an alternative technology to minimise the negative impact, provided that the cleaning efficiency and fibre quality are not compromised. This study  examined the influence of ultrasonic irradiation frequency and ultrasonic power variations on wool scouring performance at different liquor ratios. Scoured fibre, residual ash content, residual grease content, whiteness and yellowness were evaluated. The impact of liquor degassing on wool scouring effectiveness was studied. Fibre surface damage was also assessed in this work. It was observed that while there was no significant influence of ultrasonic frequency on the whiteness or yellowness of the scoured fibres, wool scoured at frequencies of 28 kHz and 80 kHz had more grease and dirt removed than that scoured at 45 kHz. Low ultrasonic power and degassed bath liquor increased wool grease removal ability. Ultrasonic treatment caused scale cracking/peeling in some wool fibres. More severe cuticle damage was observed in fibres scoured at the lower frequency. This damage resulted in increased dye uptake by the fibres.

Ultrasonic scouring of wool and its effects on fibre breakage during carding

Ultrasonics has shown the potential to reduce the cost and environmental impact of textile processing. This work investigates the impact of ultrasonic scouring on fibre entanglement caused during the scouring process. Levels of fibre entanglement were quantified by measuring fibre length using OFDA4000 after carding. A significant reduction in fibre entanglement after ultrasonic scouring was observed and this was due to a reduced fibre migration in the wash bath when compared with the mechanical agitation seen in conventional scouring process. Fibre cuticle scale damage resulting from the ultrasonic irradiation may also have contributed to the reduction in fibre entanglement. A reduced level of fibre entanglement from ultrasonic wool scouring leads to a reduction in fibre breakage during carding.

Fibre properties affecting the softness of wool and other keratins

The emerging market for next-to-skin knitwear requires wool to satisfy the consumer’s tactile requirements for softness. The role of the fibre’s surface and physical properties on fibre and fabric softness was examined. The fibre’s cuticle properties were found to have a greater influence on softness than the fibre’s mechanical properties.

What happens during natural protein fibre dissolution in ionic liquids

Here, we monitor the dissolution of several natural protein fibres such as wool, human hair and silk, in various ionic liquids (ILs). The dissolution of protein-based materials using ILs is an emerging area exploring the production of new materials from waste products. Wool is a keratin fibre, which is extensively used in the textiles industry and as a result has considerable amounts of waste produced each year. Wool, along with human hair, has a unique morphology whereby the outer layer, the cuticle, is heavily cross linked with disulphide bonds, whereas silk does not have this outer layer. Here we show how ILs dissolve natural protein fibres and how the mechanism of dissolution is directly related to the structure and morphology of the wool fibre. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Reproduction, egg morphology and development observed in Monographis queenslandicus (Diplopoda: Polyxenidae)

This study provides new insight into penicillate sexual behaviour and eggdevelopment as observed in Monographis queenslandicus Huynh et Veenstra, 2013 (Polyxenidae). The developing eggs were found to have two distinct stages, namely the chorion and pupoid, which both proved to be of 12–14 days duration. Both stages were characterized by distinctive external morphology. Morphological features observed pre ecdysis included the development of a smooth, tough membrane of the chorion. In contrast, the pupoid stage exhibited an embryonic cuticle with tiny spines, which were later being used to rupture the chorion. Additionally, an aperture bordered by protective sensilla located on the anterior of the pupoid is described for the first time.How to cite this article: Huynh C., Veenstra A.A. 2014. Reproduction, egg morphology and development observed in Monographis queenslandicus (Diplopoda: Polyxenidae)