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Wang, Xungai, Liu, Xin, Hurren, Christopher and Lin, Tong 2009, Recent research on natural fibres and textiles, in Natural fibres in Australasia : proceedings of the combined (NZ and AUS) Conference of The Textile Institute, Dunedin 15-17 April 2009, Textile Institute (NZ), [Dunedin, New Zealand], pp. 1-9.

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In Natural Fibres in Australasia: Proceedings of the Combined (NZ and AUS) Conference of The Textile Institute, Dunedin 15-17 April 2009, Wilson, C. A. and Laing, R. M. Editors. p1-9. Dunedin, New Zealand: The Textile Institute (NZ). ISBN: 978-0-9598019-3-4

Recent research on natural fibres and textiles

1 1 1 1 X. WANG , X. LIU , C. J. HURREN AND T. LIN

1Centre for Material and Fibre Innovation, Deakin University, VIC 3217, Australia e-mail: [email protected] Abstract. This paper provides an overview of recent research on a range of natural fibres and textiles. The focus is on work carried out at Deakin University’s Centre for Material and Fibre Innovation, which is a multidisciplinary research centre with over 100 researchers. The fibres include hemp, wool, silk, and alpaca fibres. Research on yarns, fabrics, and fine powders made from wool and silk fibres are briefly discussed also. The within-fibre diameter variation of wool has been examined systematically, which highlights the importance of this hard-to-measure fibre attribute. A relationship between hemp fibre fineness and residual gum content has been established, which provides a rapid means of assessing the residual gum content in the degummed hemp fibres. Silk and wool fibres have been converted into ultrafine powders for advanced applications. The Resistance to Compression (RtC) behaviour of wool and alpaca fibres has been closely examined, which challenges the belief that RtC is a good indicator of fibre softness. Ways of reducing the hairiness of natural fibre yarns, predicting the pilling propensity of wool knits, and functionalising fabrics for superhydrophobicity and photochromic or colour changing effects are discussed.

Keywords: natural fibres, yarn, fabric, powdering single fibre level, reducing the energy and 1. Introduction environmental impact of wool textile processing Natural fibres from plants or animals have activities, and exploring new uses for wool. been used for thousands of years. For discerning Fibre irregularities are inherent to wool and consumers today, natural fibres remain the fibres other animal fibres. While between-fibre diameter of choice for textiles and home furnishings. variations can now be easily measured with The Centre for Material and Fibre Innovation instruments like OFDA and Laserscan, examining (CMFI) at Deakin University conducts basic and within-fibre diameter variation has been a tedious applied research into a range of materials in a task. Yet such within-fibre dimensional variation multi-disciplinary environment (Figure 1). CMFI has been known to have significant effects on has excellent facilities for the physical and fibre mechanical properties (Wang 2000; Zhang chemical characterisation including state of the art and Wang 2000; Zhang and Wang 2001). Using electron microscopes. This capacity is numerical modelling and sinusoidal waves to complemented by our surface functionalisation simulate diameter variations along the length of a and numerical modelling facilities. fibre (Figure 2), we have examined the effects of This paper gives selected examples of our the level and frequency of within-fibre diameter research in the natural fibre and textile areas. variations on the tensile and flexural behaviour of single fibres (Zhang and Wang 2001; He, Zhang et al. 2001a; He, Wang et al. 2001b; He and Wang 2002). We have shown that the classical Weibull distribution has to be modified for application to irregular fibres (Zhang, Wang et al. 2002). Recently and for the first time, we also introduced the concept of limiting irregularity to wool fibres (Deng, Wang et al. 2008), assuming random distribution of the cortical cells within a wool fibre. Wool scouring is one of the most important processes in early-stage wool processing. Current aqueous wool scouring is an energy and water intensive process. Our research on ultrasonic FIGURE. 1. Research activities at CMFI scouring for greasy wool (Hurren, Zhang et al. 2006) showed that, 2. Natural fibres ultrasonic agitation has significantly improved the removal of grease from the wool fibre when used 2.1 Wool in conventional non-ionic aqueous scouring. Wool research is of great significance to key Reduced detergent concentrations and water could wool producing nations such as Australia and be used with ultrasonic agitation to achieve the New Zealand. Our research focus has been on same level understanding the unique attributes of wool at the

for many years. Measuring RtC is an objective way to reflect fibre compressibility. Wool with greater RtC generally has a harsher handle (Shah and Whiteley 1971; Stevens 1994). While the RtC

and curvature of wool usually decrease with increased mean fibre diameter, we have found that alpaca fibres do not follow the same trend (Figure

4) (Liu, Wang et al. 2004a).

A multiple regression analysis on the effect of both diameter and curvature on RtC revealed that

the dominant effect on RtC is curvature or crimp for wool, and that for alpaca is fibre diameter FIGURE 2. Modelling irregular fibres (Liu, Wang et al. 2004a). In fact, a very fine wool fibre with a high curvature usually has much of scouring as conventional scouring. Ultrasonic higher RtC value than a much coarser fibre with a agitation also reduced fibre entanglement during low curvature, even though the fine fibre is much scouring. The fibre surface was modified by softer than the coarser one. This study suggests ultrasonic agitation causing moderate cracking of that the current RtC test method is not suitable for the cuticle on some fibres (Figure 3). The fibre quantifying natural fibre softness. cracking had negligible effect on fibre strength but increased the rate of pre-metalised dye uptake A simple technique has been developed to of the fibre. evaluate fibre softness objectively, by pulling a bundle of parallel fibres through a series of pins

(Liu, Wang et al. 2004b). The specific pulling force reflects the combined effect of fibre surface properties, fibre

(kPa) Wool (R2=0.55) 9 Alpaca (R2=0.16) 8

7 Compression to 6

Resistance 4

3 FIGURE 3. Cracking of wool cuticle 14 16 18 20 22 24 26 28 30 32 34 Mean Fiber Diameter (µm) Wool is a natural protein fibre, composed of FIGURE 4. Different RtC trends for alpaca and wool more than 20 amino acids. There is an increasing (Liu, Wang et al. 2004a) interest in the conversion of protein fibres like diameter and fibre rigidity. Fibres with finer wool into protein, as a source of cosmetic microns, lower bending rigidity and smoother ingredients or protein for animal food. Recently, surface have a lower specific pulling force and are we coated hydrolysed wool protein onto softer. Alpaca and wool fibres have been used in electrospun nanofibre membranes and applied this study to validate this technique and the results these wool protein coated membranes as wound suggest that the pulling force measurement dressing materials (Liu, Lin et al. 2008). Two technique can reflect the difference in fibre biodegradable polymers, poly-ε-caprolactone softness. (PCL) and poly (vinyl alcohol) (PVA), were used Alpaca fibres have been used for pillow and to electrospin nanofibre membranes. The results quilt filling, due to their distinctive warmth and from in vivo animal trial showed that protein softness attributes. In particular, coarse alpaca coated membranes enhanced wound healing rate fibres, which have poor spinnability and low more than the un-coated PVA and PCL nanofibre commercial value, have been extensively used. membranes, suggesting that the wool protein Coarse and stiff fibres often poke through bedding assisted with the generation of new skin tissues. covers, causing discomfort to the users of these products. Therefore, removing coarse fibres from 2.2 Alpaca fibre the alpaca filling material is desirable for these Superior flexibility and soft handle are distinct applications. We used a prototype cashmere attributes for alpaca fibres. The softness of wool dehairing machine to dehair alpaca fibres (Wang, has been evaluated by a Resistance to Singh et al. 2008). Compared to the raw fibre and Compression (RtC) tester within the wool industry dropped fibre, the dehaired alpaca fibre has a

smaller coefficient of variation of fibre diameter, characteristic of the chemical bond as can be seen less coarse fibres greater than 30 µm and a higher in the annotated spectrum which creates a average fibre curvature. These changes are molecular fingerprint of the sample. Like a important for the fibre applications such as filling. fingerprint no two unique molecular structures The mean fibre diameter difference between produce the same infrared spectrum. This makes dehaired and undehaired alpaca fibre is quite infrared spectroscopy useful for quantitative and small. The benefit of this dehairing process is in qualitative analysis. For cashmere and wool enhanced quality of the final alpaca product. The protein studies, the regions of interest are the dehaired alpaca fibres are cleaner, bulkier and amino I, amino II and amino III absorption bands, softer (Figure 5). As a result of this research, which are located approximately in the 1600, alpaca dehairing is now carried out commercially 1500 and 1300 cm-1 regions, respectively. It has in Australia. been demonstrated that higher muster of chemical bands of cashmere at selected wavelength ranges may provide a means to differentiate cashmere from wool (Liu, Ma et al. 2008). Another attempt is to extract fibre surface texture features for classifying cashmere and superfine merino wool fibres, by using the two- dimensional dual-tree complex wavelet transform (2DDTCWT) decomposition and reconstruction (Zhang, Palmer et al. 2008). An effective way to extract features that represent cuticle scale height, scale shape and scale interval has been provided, FIGURE 5. A comparison of alpaca fibres before and which is needed to develop an automated and after dehairing (Wang, Singh et al. 2008) objective system for animal fibre identification.

2.3 Cashmere 2.4 Hemp Cashmere is classified as one of the luxury Hemp has been produced for thousands of fibres because of its appearance, softness, warmth, years as a source of fibre for paper, clothing and handle and comfort, and also because cashmere construction materials because it is extremely fibres are rare and expensive (Franck 2001). durable. The removal of lignin from hemp fibre is However the image of cashmere and its products critical to fibre properties and resultant products has been damaged in recent years because when making clothing and other textile products. cashmere fibres or fabrics may be adulterated with A study on the efficiency of degumming hemp other cheaper fibres, such as wool (with similar TM fibres using different chemical retting recipes has diameter), goat hair, Optim wool, chlorinated been done by Deakin researchers (Hurren, Wang wool or even synthetic fibres (Yao, Ma et al. et al. 2002). Different chemical methods resulted 1997; Chan and Langley 2005). Rapid and reliable in products with varied fibre width, colour and fibre identification has remained a challenge for softness of handle. the cashmere industry. Current standard test methods for analysing blends of specialty fibres Further study on hemp investigated the with sheep’s wool are based on scanning electron relationship between fineness and residual gum microscope (SEM) and light microscopy (Phan, content of degummed hemp fibres (Beltran, Wortmann et al. 1988; American Society for Hurren et al. 2002). Seventeen degummed hemp Testing and Materials 1993; Wortmann, Phan et samples were examined for mean and coefficient al. 2003). The test accuracy that can be achieved of variation (CV) of fibre width (measured on the depends largely on the operator’s expertise with Optical fibre diameter analyser – OFDA) and the visual/microscopic appearances of different residual gum content. A strong linear co-relation fibres. The current operator-based method is between the mean of fibre width and the residual tedious and subjective. It is desirable to develop gum content was found (Figure 6). This rapid, objective and automatic methods to identify significant finding provides a much faster method and subsequently classify animal fibres. Two new to replace the tedious evaluation of residual gum approaches were examined at Deakin for this content of retted bast fibres. purpose (Liu, Ma et al. 2008; Zhang, Palmer et al. Hemp has been used as reinforcement 2008). materials in cement matrices for many years. The Fourier Transform Infrared Spectroscopy Hemp fibre has high tensile strength and strong (FTIR) technique was used as it offers a greater tolerance under an alkali environment. A ease of use with reduced time, and potentially systematic study on hemp fibre reinforced provides more information for larger samples as it concrete composites (HFRC) examined some investigates internal chemical structure (Liu, Ma major fibre properties and their effects on et al. 2008). The wavelength of light absorbed is mechanical properties of composites (Li, Wang et

al. 2006). The study has revealed that the interaction of aggregate size and fibre length is the chief factor that affects the compressive strength,

20.0 FW=0.233Rg + 19.247 17.5

1(%) 5.0

12.5 FIGURE 7. Wool powder used in synthetic filament content

10.0 In fine powder form, wool also becomes

gum R 0.92315

7.5 highly reactive and absorbent. This can be reflected in the dye uptake behaviour. In a recent Residual 5.0 study (Wen, Brady et al. 2008), merino wool top 2.5 with a mean fibre diameter of 20.4 µm was cut 0.0 into 2 mm snippets using a Frisch Pulverisette 19 19.0 19.5 20.0 20.5 21.0 21.5 22.0 22.5 23.0 23.5 24.0 24.5 Mean fibre width (µm) rotary chopper. The chopped wool top was ground into particles using a rotary ceramic mill; FIGURE 6. Residual gum content in degummed hemp it was then chlorinated with 4% fibres versus mean fibre width (Beltran, Hurren et al. dichloroisocyanuric acid (sodium salt) for 45 2002) minutes at room temperature (pH 4 - 4.5), and and the hemp fibre content is the main factor that finally subjected to an air-jet milling process. The affects the flexural strength and flexural mean particle size (on a number basis) was toughness. The results from this study showed that determined to be around 1.40 µm, measured in the wet mix method for making composites is isopropanol using a Malvern Mastersizer 2000. The BET surface area of the wool powder was better than the dry mix method in terms of 2 flexural properties, possibly due to the enhanced measured at 4.02 m /g using a BET-N2 technique bonding between fibre and matrix. These with an ASAP 2020 Surface Area Porosity properties make the HFRC more suitable for use Analyzer. This wool powder was then evaluated in pavements, because they can reduce shrinkage for dye uptake in comparison with the wool top and activated charcoal (BET surface area of the and cracking of paving products. Hemp fibres 2 have excellent potential, as reinforcement charcoal was 554 m /g; the mean particle size (in material. They can be recycled and grown water) was determined to be 1.64 µm). Figure 8 ecologically, and have no waste little disposal shows the uptake of dye versus time for Acid Red problems. 88, a monosulphonated acid dye. Dye uptake experiments were carried out at 1.0 g/l dye 0 2.5 Natural Fibre Powders concentration, pH 4.5, 25 C and a liquor ratio of 200:1. Small samples of dye liquor were removed In an attempt to find new applications for at regular intervals and filtered. The concentration traditional fibres such as wool, we have converted of dye in each filtrate was determined using a wool and silk fibres into ultrafine powders and Cary-3 UV-Visible Spectrophotometer. From examined the properties and applications of these Figure 8, it can be seen that the wool top took up fine powders. These fibres are known for their virtually no dye after 90 minutes, whereas with resilience and viscoelasticity. As such, powdering the fine wool powder there was 95% exhaustion these fibres is a formidable challenge. after less than 10 minutes. Furthermore, the In collaboration with researchers at Wuhan equilibrium uptake of dye by the charcoal was University of Science and Engineering and similar to that of the wool powder. In the case of Beijing Institute of Fashion Technology, we charcoal, dye would be expected to be adsorbed converted clean wool into ultrafine powders using only on to the surfaces of the carbon particles. a combination of milling techniques, and With the wool powder, disruption of the cuticle incorporated the wool powder into polypropylene during powdering and swelling of the wool (PP) filament through a melt extrusion process particles in water have combined to increase the (Figure 7). The natural wool polymer gives the adsorption capacity by allowing migration of dye modified PP filaments enhanced moisture and dye into the interior of the particles, even at room uptake. temperature. The high chemical absorption properties for the fine powders under mild conditions may enable cleaning and recycling of environmental and industrial pollutants such as heavy metals and toxic

that combining Sirospun with Solospun in a single 100 Solo-Siro process (Figure 10) can reduce the 90 hairiness (S3 value) of worsted yarns by over 70% 8(%) 0 (Najar, Khan et al. 2006). 70

5uptake 0 wool powder We have developed a modified yarn hairiness 40 activated charcoal composition model, and used this model to

3dye 0 wool top (fibre) explain the hairiness results of blend yarns. A 20 study on hairiness of selected worsted wool, 10 cashmere and cashmere/wool blend yarns has 0 shown that, fibre 0 10 20 30 40 50 60 70 80 90 100110120130 contact time (minutes)

FIGURE 8. Dye uptake versus time for wool powder, wool top and activated charcoal (Wen, Brady et al. 2008) chemicals in an efficient and environmentally friendly manner, using naturally derived organic materials. We have also converted silk fibres into very fine powders (Rajkhowa, Wang et al. 2008; Rajkhowa, Gil et al. 2009; Rajkhowa, Wang et al. 2009). In collaboration with Tufts University in FIGURE 10. Solo-Siro spun process (Najar, Khan et al. America, silk powders were used to reinforce 2006) scaffolds for tissue engineering work (Rajkhowa, Gil et al. 2009). The preliminary results have shown that compared with similar scaffolds curvature has a significant effect on yarn hairiness without the silk powders, the compression (Wang, Chang et al. 2006). Yarns spun from modulus and yield stress were increased fibres with a higher curvature have lower significantly when silk powders were used to hairiness than yarns spun from similar fibre of a reinforce the scaffold. Figure 9 shows the process lower curvature. This is likely due to the increased of making the porous composite scaffolds from fibre/fibre cohesion provided by the higher silk biomaterials. Work is on-going in this area. curvature wool, which helps with the fibre security during spinning. The effect of wool curvature in the cashmere/wool blend yarn diminishes as the proportion of cashmere in the yarn increases. This is due to the reduced presence of wool in the outer regions of the yarn. For the blend yarns made from wool and cashmere of similar diameter, yarn hairiness increases with the increase in the cashmere content in the yarn. This is likely to be caused by the increased proportion of the shorter cashmere fibres in the surface regions of the yarn, leading to increased yarn hairiness.

FIGURE 9. Process for making porous composite 3.2 Mill spinning performance prediction scaffolds (Rajkhowa, Gil et al. 2009) Different spinning mills use different raw materials, processing methodologies, and 3. Yarns equipment, all of which influence the quality of the yarns produced. It is difficult to use a 3.1 Yarn hairiness universal empirical/theoretical model for mill Yarn hairiness affects both fabric quality and specific predictions. We developed a multilayer the efficiency of fabric manufacturing processes. perceptron algorithm (MLP) model for the Yarn hairiness has been reduced significantly by purpose of building a mill specific worsted incorporating an air jet in either the ring spinning spinning performance prediction tool (Beltran, process (JetRing) (Wang and Miao 1997; Wang, Wang et al. 2006a). Sixteen inputs are used to Miao et al. 1997) or a winding process (JetWind) predict key wool yarn properties and spinning (Beltran, Wang et al. 2007). We have also shown performance, including number of fibres in cross-

section, unevenness (U%), thin places, neps, yarn ophthalmic lenses, optical switches (Berkovic, tenacity, elongation at break, thick places, and Krongauz et al. 2000; Feringa, van Delden et al. spinning ends-down. Validation of the model on 2000; Irie 2000), sensors (Ock, Jo et al. 2001), mill specific commercial data set of wool yarns micro-image information storage (Bamfield 2001) shows that the general fit to the target values is and potential military protection usage. Colour good. Subsequent comparison against the change in photochromic compounds typically predicted outputs of Sirolan Yarnspec™ confirms comes from the shift of optical absorption due to the overall performance of the artificial neural molecular structure or conformation change. network (ANN) method to be more accurate for Several attempts of applying photochromic dyes mill specific predictions. to synthetic fabric, cotton or silk fabric have shown the colour change in the presence of UV 4. Fabrics light (Shah, Christie et al. 2005; Lee, Son et al. 2006). However, these works encountered the 4.1 Pilling prediction problems of slow optical response, low exhaustion and photostability and poor fabric handle Many fibre, yarn and fabric properties properties. Researchers at Deakin have overcome contribute to pilling of wool knitwear. It is these problems by choosing suitable matrix difficult to identify the degree of influence and the materials based on sol-gel technology to host synergistic effect of each on fabric pilling photochromic dyes (Cheng, Lin et al. 2007; propensity. A conventional means of ranking Cheng, Lin et al. 2008; Cheng, Lin et al. 2008). input variables is to design an accurate empirical model. However, it is not practical for We used a spirooxazine and different silane establishing such multi-linear relationships. An precursors to produce hybrid photochromic silica artificial neural network (ANN) pilling model has coating on wool fabrics. The “nano-sized” tiny been developed to predict pilling output by pores in silica provide sufficient free volume for sensitivity analysis and forwards/backwards the photochromic molecules to accomplish the elimination search (Beltran, Wang et al. 2005; photochromic transformation. An example of the Beltran, Wang et al. 2006b). The results show that optical absorption of the photochromic fabrics is fabric cover factor is the dominant physical shown in Figure 12. Without UV irradiation, the property for the propensity of fabric pilling solution has no apparent absorption in the visible (Figure 11). Others such as short fibre content, region (400~750 nm). However, a strong bundle strength, fibre diameter, length distribution absorption peak (around 620 nm) occurred when and fibre curvature, play important roles on the fabric was exposed to UV light. From UV pilling, but to a lesser extent. This study may help irradiation to saturated absorption, it took about manufacturers and knitwear designers in choosing 28 s, and about 90% of the saturated absorption the most appropriate materials and structures to was reached in the first 20 s. After the removal of reduce the pilling propensity of wool knitwear. UV exposure, the fabric colour diminished very quickly within a minute, indicating a rapid colour

2.4 fading. The fabric also showed good durability to abrasion and washing and retained the softness of 2.0 original fabric.

1.6

1.2

0.8 Coefficient value

0.4

0.0 Cover Count Thin HauteurTwist ShrinkFibre Knit HairinessDiameterFolding Thick Short BundleCVD (%)CVH (%)Curvature

structure place factor diameter place fibre factor (tex) proofed (mm) twist tenacity >30um (deg/mm) (km) (Kt) (km) <30mm (mmtex) ratio (%) (cN/tex) (%)

Inputs

FIGURE 11. Ranking of factors affecting fabric pilling propensity (Beltran, Wang et al. 2005) FIGURE 12. Optical absorption behaviour

4.2 Photochromic wool fabric Reversible colour change of photochromic compounds upon UV irradiation have attracted interests in many different areas such as

removed the C21 fatty acid (F-layer) from the wool 4.3 Superhydrophobic fabric fibres, leading to the exposure of, and generation Recently, superhydrophobic surfaces (with a of charged groups on, the surface of the epicuticle. water contact angle greater than 150 degrees) In addition, the results indicated that oxygen- (Johnson and Dettre 1964; Marmur 2004) have based reactive species (derived from atmospheric been extensively researched due to their potential oxygen and water vapour) were responsible for applications in many areas such as antisticking, the fibre surface modification. anticontamination, and self-cleaning technologies. The plasma treatment had little effect on the Most of the superhydrophobicity techniques adsorption rate of relatively hydrophobic, involved a tedious and multiple-step procedure, sulphonated wool dyes, consistent with the greater which is impractical for fabrication of importance of hydrophobic dye-fibre interactions superhydrophobic surfaces on a large-scale. At compared with electrostatic (ionic) effects in those Deakin, a functional wool fabric with surface cases. For relatively hydrophilic dyes, the superhydrophobicity was produced by a relatively adsorption rate was increased significantly with simple one-step coating of a particulate silica sol the plasma treatment (Figure 14), consistent with solution (co-hydrolysed tetraethylorthosilicate the greater importance of electrostatic interactions (TEOS)/fluorinated alkyl silane) under alkaline between the more strongly anionic, hydrophilic condition (Wang, Fang et al. 2008). This sol dye molecules and a more highly charged, solution can be easily coated onto various hydrophilic fibre. The plasma treatment also substrates (e.g. polyester, wool and cotton fabrics, enhanced the uniformity of dye adsorption. electrospun nanofibre mats, and filter papers) to form a transparent film by padding, spraying or spin coating (Figure 13). The resultant coating of good adhesion to the substrates showed a water contact angle over 170° and a sliding angle less than 7 degrees.

FIGURE 14. Adsorption of C.I. Acid Red 13 at pH 4.8, 900C; untreated fabric (■), plasma-treated fabric (●) (Naebe, Cookson et al. 2009) In a further preliminary trial, plasma treatment has resulted in much reduced pilling propensity of woven wool fabrics (Figure 15). This may be due to the changed fibre surface frictional properties after the plasma treatment.

FIGURE 13. Superhydrophobic fabrics 5. Conclusion This paper has provided an overview of some 4.4 Plasma surface treatment recent research into natural fibres, yarns and Increased environmental awareness has driven fabrics. The focus has been placed on selected the investigation into more sustainable physical or research examples in the Centre for Material and chemical means of fibre surface modification. Fibre Innovation (CMFI) at Deakin University. In These may eventually replace the common “wet” addition to natural fibres, the Centre also conducts chemical treatment. One of the most promising research into a range of manufactured fibres, treatments for wool surface modification has been including electrospun nanofibres, as well as many low-temperature plasma (LTP). LTP treatments non fibrous materials. can reduce fibre felting shrinkage and improve fibre wettability and fibre cohesion. 6. Acknowledgements An atmospheric pressure, helium plasma The work reported in this paper has been treatment – with a relatively short exposure time – supported by Australian Research Council (ARC), has been used to modify the surface of wool fibres Australian Wool Innovation (AWI), Rural (Naebe, Cookson et al. 2009). The treatment Industries R&D Corporation (RIRDC), and resulted in a significant increase in the hydrophilic AusIndustry. We also wish to acknowledge the properties of the fibre. XPS and ToF-SIMS past and present research students and research studies confirmed that the plasma effectively

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