Research Journal of Textile and Apparel Surface properties of radio frequency plasma treated wool and denim fabrics Ahmed Hala, Gozde Yurdabak Karaca, Esin Eren, Lutfi Oksuz, Ferhat Bozduman, Melek Kiristi, Ali Ihsan Komur, Ali Gulec, Aysegul Uygun Oksuz, Article information: To cite this document: Ahmed Hala, Gozde Yurdabak Karaca, Esin Eren, Lutfi Oksuz, Ferhat Bozduman, Melek Kiristi, Ali Ihsan Komur, Ali Gulec, Aysegul Uygun Oksuz, "Surface properties of radio frequency plasma treated wool and denim fabrics", Research Journal of Textile and Apparel, doi: 10.1108/RJTA-02-2016-0003 Permanent link to this document: http://dx.doi.org/10.1108/RJTA-02-2016-0003 Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) Downloaded on: 16 May 2017, At: 07:02 (PT) References: this document contains references to 0 other documents. To copy this document: [email protected] The fulltext of this document has been downloaded 1 times since 2017* Access to this document was granted through an Emerald subscription provided by emerald-srm:333301 [] For Authors If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.com Emerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services. Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. *Related content and download information correct at time of download. Surface properties of radio frequency plasma treated wool and denim fabrics ABSTRACT Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) The effects of hydrochloric acid (HCl), hydrazine, methyl methacrylate (MMA), styrene and hexamethyldisiloxane (HMDSO) treatment by radio frequency (rf) plasma grafting on surface properties of wool and denim fabrics were investigated. During plasma treatments, processing time was varied under optimized plasma conditions (50 W, rf: 13.56 MHz). All fabrics were comprehensively investigated by means of scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and contact angle measurements. Our experimental data show that the rfplasma processing has an important effect on the wettability properties of wool and denim fabrics. The results indicated that HCl plasma treatment significantly improves the hydrophilicity of wool and denim fabrics. Keywords: Surface modification, wool, denim, rf plasma 1. Introduction Plasma has diverse applications in many branches of science and technology, including the production of many modern household objects [Plasma, 2001]. Plasma is a mixture of ions, electrons, and neutral particles (atoms, free radicals or molecules), which give it a distinctive potential for surface modification [Kale & Desai, 2011]. Plasma technology can be viewed as a low-cost, rapid processing, and eco-friendly technology [Shadi, 2014]. Thus, plasma technology also provides several advantages over conventional chemical processes. Plasma technology has been used in many areas such as electronics, manufacturing, biomedical devices, thin film technology and automotive [Kale & Desai, 2011]. Additionally, plasma provides efficient, fast, and low cost processing technique for coating, painting, whitening, and other processes particularly in the textile industry [Prysiazhny, 2013]. Non-thermal plasmas are especially suitable for textile processing because most textile materials are heat sensitive polymers [Morent et al., 2008]. The textile industry is moving toward the application of waterless or low-water-based processing technologies for ecological reasons [Samanta et al, 2014]. Plasma treatment has diverse effects depending on the experimental conditions including cleaning (removal of contaminants from the surface), etching (changes in surface roughness and morphology) and functionalization (production of new functional groups at the surface) [Peršin et al., 2012], this allows it to provide desired properties on targeted application areas such as less shrinkage for wool or improved hydrophobic/hydrophilic coatings [Canal et al., 2007]. To evaluate the improvement in water uptake of polyester and acrylic fabrics obtained by plasma treatment, the capillary rise method was applied and wettability of samples were investigated [Ferrero, 2003]. In addition, hydrophilizations of cotton fabrics were developed by oxygen plasma treatment [Poll et al., 2001]. Another study for surface modification using different plasma gases exposed wool and cotton fabrics to a low temperature plasma caused changes in surface roughness [Sun & Stylios, 2006]. The effect of plasma treatments on the surface properties of textile fibers, air plasma and dichlorodifluoromethane (DCFM) plasmas were studied. Air plasma produced enhanced water wicking, DCFM plasma resulted in producing a highly water-repellent, hydrophobic surface [Bhat et al., 2011]. Plasma treatment affects/modifies only the material surface without any molecular fragmentation at the inner layers [Poll et al., 2001]. Wettability is one of the important features for many applications such as dyeing, finishing and detergency [Gotoh & Yasukawa, 2010]. As a result of the plasma modifications, wettability of the textiles can be firmly boosted because of the increased amount of functional Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) groups on the surface such as –COOH, -OH and -NH2 [Morent et al., 2008]. Plasma treatment influenced the surface topography, which further increases the impact of the surface chemistry on the contact angle. Hydrophilization is typically temporary, and either a partial or whole hydrophobic recovery is generally observed [Jokine et al., 2012]. A variety of configurations of plasma processing such as atmospheric-pressure plasma and lowpressure (vacuum) plasma have been used to modify textile surfaces by generating active species of plasma on the surface. Non-thermal radio-frequency (rf:13.56 MHz) powered plasma sources provide advanced control for surface properties and good stability of fabrics at low cost [Radetic et al., 2009]. Among these techniques, atmospheric pressure rf plasma systems are widely used for textile surface modifications because of their rapid and efficient processing. Additionally, it is environmentally friendly since it saves water and energy [Park & Koo, 2014]. On the other hand, vacuum plasma provides easier control of the parameters such as air permeability, moisture and the elimination of the volatile toxic chemicals for the treatments [Samanta et al., 2012]. 2. Materials and methods 2.1 Materials Denim and Wool fabrics were obtained from Middle Anatolia T.A.S. Kayseri / Turkey and YUNSA T.A.S. Tekirdag / Turkey. Hexamethyldisiloxane (HMDSO, 98.5%), Styrene (99%), and Hydrazine (% 98) were purchased from Sigma-Aldrich Chemistry. Methlymethacrylate (MMA, 99%) and Hydrochloric acid (HCl, 37%) were received from Merck-Schuchardt and Riedel-deHaen, respectively. 2.2 Low Pressure RF Plasma Treatment In-situ plasma treatments of denim and wool using different chemicals were carried out by the homemade Plus plasma capacitively coupled plasma (RF-CCP) reactor (Fig. 1). The upper electrode was powered with 13.56 MHz rf voltage while the bottom electrode was grounded. The aim of this study is to investigate the surface properties of rf plasma modified denim and wool fabrics, comparatively. The hydrophobic and hydrophilic properties of denim and wool fabrics were improved using different chemicals such as hydrazine, methyl methacrylate (MMA), styrene, hydrochloric acid (HCl), and hexamethyldisiloxane (HMDSO) depending on their potential applications. Wettability properties of denim and wool fabrics were studied with different chemicals by time intervals then surface properties were investigated by contact angle measurements, scanning electron microscopyenergy dispersive spectroscopy (SEM-EDS). The results showed that rf plasma processing has significant effect on the targeted fabrics. Fig. 1. Rf plasma setup. Denim and Wool substrates were prepared in 4x2 cm2 dimensions and placed in the quartz glass plasma vacuum reactor. Denim and wool fabrics were treated with HCl, hydrazine, styrene, MMA and HMDSO vapors in the vacuum plasma reactor in Fig. 1. Plasma treatment time was 15, 30 and 45 minutes in optimized plasma conditions (50 W and rf:13.56 MHz). The abbreviations of all fabrics are given in Table 1. 2 Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) Table 1. The abbreviations of all wool (WF) and Denim (DN) fabrics 2.3 Instrumental studies Surface morphology and elemental analysis of the samples were examined using SEM-EDS system, Tescan Vega II L Su and Oxford Swift. Contact angle measurements were examined by Sessile drop method (Clear View Instruments). A light source was kept behind droplet to enhance the boundary of the droplet for the precise measurement of the contact angle. Sample Chemical Treatment Plasma treatment time (min) WF, DN untreated - WF,DNHCl-15 HCl 15 WF,DNHCl-30 HCl 30 3. Results and Discussion WF,DNHCl-45 HCl 45 3.1 SEM Results WF,DNHDMSO-15 HMDSO 15 WF,DNHDMSO-30 HMDSO 30 WF,DNHDMSO-45 HMDSO 45 WF,DNHYD-15 Hydrazine 15 WF,DNHYD-30 Hydrazine 30 WF,DNHYD-45 Hydrazine 45 WF,DNMMA-15 MMA 15 WF,DNMMA-30 MMA 30 WF,DNMMA-45 MMA 45 WF,DNSTY-15 Styrene 15 WF,DNSTY-30 Styrene 30 WF,DNSTY-45 Styrene 45 Plasma is a partially ionized gas that contains ions, electrons, and other neutral species at many different energy levels. When energized by an electrical field, free radicals, ions, and atoms are formed that can interact with solid surfaces that have been placed in the plasma (Ramos, Runyan, and Christensen, 1996). SEM images of plasma treated and untreated wool fabrics are shown in Fig. 2. Longitudinal striation reveals the fibril structure of the fibers. The interstitial space of textile fiber increased on WF-HDMSO-45 fabric (Fig. 2c). Therefore, it can provide an easy pathway for the liquid to enter the fibers resulting in enhanced hydrophilicity [Navaneetha Pandiyaraj & Selvarajan, 2008]. Fig. 2e show the surface morphology of the MMA plasma treated wool fabric by different time. After plasma treatment pore size and roughness of the wool fibers increased significantly (Fig. 2e) and resulted in increments of hydrophilic surface property. The surface of styrene modified wool (Fig. 2f) showed smoother morphology by increasing treatment time. Wool fibers possess a scale-like cuticle on the cortex along the fiber length [Zimmerman et al., 2011]. The external surface of wool fiber contains some boundaries such as escarpments [Kan, 2007]. After plasma treatment, the escarpments were slightly lifted in fiber surface. But, there was no severe damage, i.e complete scale removal on all plasma treated wool fiber surface. 3 Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) Fig. 2. SEM images of WF (a), WF-HCl-15 (b), WF-HDMSO-45 (c), WF-HYD-45 (d), WF-MMA-45 (e), WF-STY-30 (f). Fig. 3. SEM images of DN (a), DN-HCl-15 (b), DN-HDMSO-15 (c), DN-HYD-15 (d), DN-MMA-45 (e), DN-STY-30 (f). Fig. 3 shows the variation in the surface morphology of plasma-treated and untreated denim fabrics. As seen in Fig. 3b, HCl-treated denim fabrics displayed rougher surface compared to the untreated one (Fig. 3a). As shown the porous areas of plasma treated denim fabrics especially DN-HCl-15 have been partially removed. Fig. 3b shows that the size coverings were broken severely after plasma treatment. Presumably, the size film or particles among fibers and/or coated on the denim fabric fibers were physically bombarded and chemically modified via the active and high energetic plasma species, and then removed partially via a direct gas vaporization, or even took away via plasma gas after an ablation, which resulting in the broken of the size covering (Wang et al., 2013). The surface roughness of DN-HMDSO do not change effectively by plasma treatment time (Fig. 3c). Hydrazine modification improved roughness of the fiber surface, facilitating hydrophilicity (Fig. 3d). MMA treatment at 45 minute, it was observed that spaces between denim fibers do not change. SEM images of styrene treated denim (Fig. 3f) show a smooth fiber surface. After plasma treatment, each fabric showed different smooth and rough surface because of different surface modification on plasma treated fabric (Nithya et al., 2011, Pandiyaraj and Selvarajan, 2008). Plasma treatment etches the surface of fabric and induces both physical changes due to the etching effect of plasma species on the fabrics and chemical changes due to the formation of polar groups and free radicals on the fabric surface (Nithya et al., 2011). The formation of polar groups such as C=O group on fabric surface and physical etching of the fabric surface are two important factors affecting hydrophobicity and hydrophilicity of the fabric (Nithya et al., 2011). Morphology changes can cause wettability changes, but the wettability changes produced by this modification are small. Plasma oxidation reactions produce oxygen-containing functional groups (OOH, OH, CO), which are attached to the surface. These functional groups form and play an important role in increasing the hydrophilic properties of the fabrics (Sun and Stylios, 2006). 4 wool fabrics due to the abrupt absorption of the water drops. Plasma etching has an important effect on roughening of fiber surfaces and increasing the surface hydrophilicity [Ma & Hill, 2006]. The decrease of the MMA modified contact angles with increasing plasma time lead to an associated variation of the surface tension of wool fabric that allow it to have a penetration of the water drop in the wool fabric and the consequent hydrophilic behavior [Correia et al., 2015]. The above result is consistent with hydrazine plasma modification. However, there is an increase in contact angle for WF-STY fabrics due to the other modificated wool fabrics with increasing plasma treatment time. STY plasma etching did not induce the hydrophilicity of wool fabric. Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) 3.2 EDS and Contact angle results EDS and contact angle measurement results of wool fabrics are given in Table 2 and Fig. 4(af). Elemental analysis results of HDMSOtreated wool fabrics for different plasma treatment times demonstrated the presence of Si content on the fabric surface and also other elements such as C, O, and S. The highest Si element content was obtained for WFHDMSO-45 fabric. These results indicate that increasing time of exposure in plasma there is an increase of Si-O-Si, Si-(CH3)2 and Si-C bonds relatively to untreated wool fiber. The change in chemical composition for all fabric can be attributed to plasma interaction with the surface that leads to modification of its chemical structure and morphology (Ji et al., 2008). The fiber diameter of untreated WF fabric was ~ 20µm. The fiber diameter of WFHDMSO-30 fabric decreases to ~ 19.7 µm. The interstitial pore size of WF-HDMSO-30 was found to enhance with plasma (Nithya et al., 2011). The fiber diameter shrinkage can be due to elimination of the material from the substrate surface, etching contaminant layer via plasma application. Thus, the absence of contaminant layer can tend to decrease the contact angle value [Molina et al., 2015, Pandiyaraj and Selvarajan, 2008]. Table 2. EDS and contact angle results of untreated and treated wool fabrics C O S Si Contact Angle Sample (o) Weight Weight Weight Weight % % % % WF 52.228 47.712 2.362 - 127 WF-HCl-15 64.776 32.022 3.202 - 0 41.413 31.545 0.998 26.044 101 WF-HYD-45 67.004 28.781 4.215 - 24 WF-MMA-45 66.758 29.747 3.494 - 77 WF-STY-15 64.809 31.312 3.880 - 62 WF-STY-30 72.135 24.470 2.996 - 98 WF-HDMSO- Water contact angle for untreated wool is ~ 127 o. This value is higher than that of treated wool fabric due to the surface-bound fatty acid layer and limited capacity to absorb water [Carran et al., 2013]. Surface layer of wool, which composes of specific exocuticle and epicuticle features, is naturally hydrophobic. due to the disulfide bonds in its structure [Montazer et al., 2011]. As can be seen in Table 2, the contact angle decreased after all plasma treatments compared with the untreated wool fabric. Among all wool fabrics, HCl treatment has the best influence on the contact angle. The water contact angle on HCl-treated wool fabric was 0o showing the superhydrophilicity function of treated fabrics. HCl-treated wool fabric absorbed the water drops very quickly, indicating a superhydrophilic feature after plasma treatment. Untreated wool does not absorb the water drops when the contact angle is about 127o. There is no observation for contact angle measurements of HCl treated 45 5 Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) Fig. 4. Contact angle measurements of a) WF b) WF-HDMSO-45 c) WF-HYD-45 d) WFMMA-45 e) WF-STY-15 f) WF-STY-30. hydrazine, the presence of additional hydrophilic functional groups (-NH2) also induce increased moisture absorption (Zeronian and Collins, 1989). Si-C and C-H bonds of the HMDSO monomers were caused by plasma polymerization and it causes from hydrophobic surface changes [Yoshinari et al., 2009]. For MMA, it was chosen for hydrophilic chemical for wool surface modification [Lai, Shih, and Tsai, 1991]. EDS results of untreated denim fabrics reveal that it consists mostly of C and O elemental contents. For DN-HDMSO fabrics, Si content increased with plasma exposure time (Table 3). As seen from Table 3 and Fig. 5a, contact angle for untreated denim fabric was 89o (Table 3, Fig. 5a). Contact angle results of HCl-treated denim fabrics were the same as those of HCl-treated wool fabrics. When plasma treatment time for DN-HDMSO fabrics was increased from 15 to 45 min, contact angle was increased to 122o (Fig. 5b, Table 3). However, this value is higher than that of untreated denim fabric. The water droplet spread as soon as it fell, indicating hydrophilic behavior caused by hydrazine plasma treatment for 15 min (Fig.5c). Plasma treatments have an important effect on surface tension contributing to the fabric wettability and lead to dramatic changes of textile properties [Hossain et al., 2006]. Table 3. EDS and contact angle results of untreated and treated denim fabrics Si C O Weight % Weight % Sample Weight % Contact Angle (o) 52.288 47.712 - 89 52.149 47.851 - 0 DNHDMSO-15 48.488 45.296 6.216 122 DN-HYD15 56.092 43.908 - 29 DN-MMA45 61.838 38.162 - 89 67.778 32.222 - 112 78.407 20.983 - 105 DN DN-HCl-15 o Contact angle value (89 C) of DN-MMA-45 does not indicate the wettability behavior of the fabric after plasma treatment. As a result of all plasma treatment on wool and denim fabric, wetting properties of a solid surface are alterable related to surface molecular structure and the surface macroscopic properties [Molina et al., 2001]. When fabrics exposed to DN-STY-15 DN-STY-30 Fig. 5. Contact angle measurements of a) DN b) DN-HDMSO-15 c) DN-HYD-15 d) DNMMA-45 e) DN-STY-15 f) DN-STY-30 6 Acknowledgement Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) Conclusions Authors gratefully acknowledge the 1509TUBITAK International Industrial R&D Projects Grant Programme (Project No: 9110021) for financial support to this study Plasma treatment is a useful method to improve the surface properties of textiles, such as enhancing surface roughness, formation of power functional groups, as well as increasing wettability, dyeing, printing and finishing properties. Contact angle measurements show that all chemicals except styrene have increment hydrophilicity effect on wool fabric surfaces. This behavior of styrene can be attributed to polymerization of styrene on the fibers. DN-STY fabrics indicate hydrophobic behavior, unlike WF-STY fabric. HCl plasma treatments were found to be most effective in improving the hydrophilicity of denim and wool fabrics. Therefore, we definitely believe that the HCl plasma treatments on both wool and denim fabric surface are promising processes for textile finishing and dyeing areas. The contact angle for water on the wool and denim surface decrease after the fabrics were treated with HCl plasma, fabrics surface was exposed to plasma with HCl as monomer, which is probably attributed to the increase in the amount of hydroxyl of fabrics surface. Also, contact angle was found to decrease by soaking in HCl by plasma modification. 7 (HMDSO) coating on polyethyleneteraphtalate fiber by atmosperic pressure plasma polymerization’, Surface and coating Technology, vol. 202, pp. 5663-5667. [7] Jokinen, V., Suvanto, P., & Franssila, S. 2012, ‘Oxygen and nitrogen plasma hydrophilization and hydrophobic recovery of polymers’, Biomicrofluidics, vol. 6, 016501. REFERENCES Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) [1] Bhat, NV., Netravali, AN., Sathianarayanan, MP., Arolkar, GA., & Deshmukh, RR. 2011, ‘Surface modification of cotton fabrics using plasma technology’, Textile Res J., vol. 81, pp. 1014–1026. [9] Kale, K.H., Desai, A.N. 2011, ‘Atmospheric pressure plasma treatment of textiles using non-polymerising gases’, Indian Journal of Fibre and Textile Research, vol. 36, pp. 289-299. [10] Ma, M., Hill, R.M. 2006, ‘Superhydrophobic surfaces’, Current opinion in colloid and Interface Science, vol. 11, pp. 193- 202. [2] Canal, C., Erra, P., & Molina R. 2007, ‘Regulation of surface hydrophilicity of plasma treated wool fabrics’, Textile Res J., vol. 77, pp. 559–565. [3] Carran, S. R., Ghosh, A., & Dyer, J. M. 2013, ‘The effects of zeolite molecular sieve based surface treatments on theproperties of wool fabrics’, Applied Surface Science,vol. 287, pp. 467- 472. [11] Molina, R., Comelles, F., Julia, M.R., Erra, P. 2001, ‘Chemical Modifications on Human Hair Studied by Means of Contact Angle Determination’, Journal of colloid and Interface Science, vol. 237, pp. 4046. [12] Montazer, M., Pakdel, E., Monghadam, M. B. 2011, ‘The role of nano colloid of TiO2 and butane tetra carboxylic acid on the alkali solubility and hydrophilicity of proteinous fibers’, Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 375, pp. 1-11. [13] Morent, R., Geyter, N. De., Verschuren, J., Clerck, K. De, Kiekens, P., Leys, C. 2008, ‘Non-thermal plasma treatment of textiles’, Surface and coating technology, vol. 202, pp. 3427-3449. [14] Navaneetha Pandiyaraj,K., Selvarajan, V. 2008, ‘Non-thermal plasma treatment for hydrophilicity improvement of grey cotton fabrics’, Journal of materials processing Technology, 199, 130-139. [15] Park, Y., Koo, K., (2014). The EcoFriendly Surface Modification of Textiles for Deep Digital Textile Printing by InLine Atmospheric Non-Thermal Plasma Treatment. Fibers and Polymers, vol. 15, pp. 1701-1707. [16] Peršin, Z., Vesel, A., Kleinschek, K. S., Mozetič, M. 2012, ‘Characterisation of surface properties of chemical and plasma treated regenerated cellulose fabric’, [4] Correia, D.M., Ribeiro, C., Sencadas V., Botelho, G., Carabineiro, S.A.C, Gomes Ribelles, J. L., & Lanceros-Méndez, S. 2015, ‘Influence of oxygen plasma treatment parameters on poly(vinylidenefluoride) electrospun fiber mats wettability’ Process in organic Coatings, vol. 85, pp. 151-158. [5] Ferrero, F. 2003, ‘Wettability measurements on plasma treated synthetic fabrics by capillary rise method’ Polymer Testing, vol. 22, pp. 571-578. [6] Gotoh, K., & Yasukawa, A. 2010, ‘Atmospheric pressure plasma modification of polyester fabric for improvement of textile-specific properties’, Textile research Journal, vol. 81, pp. 368-378. [7] Hossain, M. M., Hegemann, D., Herrmann, A. S., Chabrecek, P. 2006, ‘Contact Angle Determination on Plasma-Treated Poly(ethylene terephthalate) Fabrics and Foils’, Journal of Applied polymer science, vol. 102, pp. 1452- 1458. [8] Ji, Y.-Y., Hong, Y.-C., Lee, S.-H., Kim S.D., & Kim S.-S. 2008, ‘Formation of super-hydrophobic and water-repellency surface with hexamethyldisiloxane 8 Textile Research Journal, vol. 82, pp. 2078-2089. [17] Plasma, (2001). http://www.plasma.de/images/download/p lasma_technology.pdf [25] Zimmerman, B., Chow, J., Abbot, A. C., Ellison, M. S., Kennedy, M. S., Dean, D. (2011) ‘Variation of Surface Charge along the Surface of Wool Fibers Assessed by High-Resolution Force Spectroscopy’, Eng Fiber Fabr. 6(2), pp. 61–66. [18] Poll, H.U., Schladitz, U., Schreite, S. 2001, ‘Penetration of plasma effects into textile structures’, Surface and coatings technology, pp. 142-144, 489- 493. Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) [19] [26] Kan, C. W. (2007) ‘Surface Morphological Study of Low Temperature Plasma Treated Wool –A Time Dependence Study’, Modern Research and Educational Topics in Microscopy, pp. 683-687. Prysiazhny,V. 2013, ‘Atmospheric Pressure Plasma Treatment and Following Aging Effect of Chromium Surfaces’, Journal of Surface Engineered Materials and Advanced Technology, vol. 3, pp. 138-145. [27] Wang, L., Xiang, Z.-Q., Bai, Y.-L. and Long, J.-J. (2013) ‘A plasma aided process for grey cotton fabric pretreatment’, Journal of Cleaner Production, 54, pp. 323–331. [20] Samanta, K.K., Gayatri, T.N., Shaikh, A.H., Saxena, S., Arputharaj, A., Basak,S., Chattopadhyay S. K. 2014, ‘Effect of Helium-Oxygen Plasma Treatment on Physicaland Chemical Properties of Cotton Textile’, International Journal of Biosource Science, vol. 1, pp. 57-63. [28] Nithya, E., Radhai, R., Rajendran, R., Shalini, S., Rajendran, V. and Jayakumar, S. (2011) ‘Synergetic effect of DC air plasma and cellulase enzyme treatment on the hydrophilicity of cotton fabric’, Carbohydrate Polymers, 83(4), pp. 1652–1658. [29] Molina, J., Fernández, J., Fernandes, M., Souto, A.P., Esteves, M.F., Bonastre, J. and Cases, F. (2015) ‘Plasma treatment of polyester fabrics to increase the adhesion of reduced graphene oxide’, Synthetic Metals, 202, pp. 110–122. [21] Samanta, K. K., Joshi, A. G., Jassal, M., Agrawal, A. K. 2012, ‘Study of hydrophobic finishing of cellulosic substrate using He/1,3-butadiene plasma at atmospheric pressure’, Surface & Coatings Technology, vol. 213, pp. 65–76. [30] Pandiyaraj, K.N. and Selvarajan, V. (2008) ‘Non-thermal plasma treatment for hydrophilicity improvement of grey cotton fabrics’, Journal of Materials Processing Technology, 199(1-3), pp. 130–139. [22] Shahidi, S. 2014, ‘Plasma sputtering as a novel method for improving fastness and antibacterial properties of dyed cotton fabrics’, The journal of Textile Institute, vol. 106, pp. 162-172. [31] Yu, J. and Zhao, X. (2001) ‘Effect of surface treatment on the photocatalytic activity and hydrophilic property of the sol-gel derived TiO2 thin films’, Materials Research Bulletin, 36(1-2), pp. 97–107. [23] Radetic, M., Jovancic, P., Puac, N., Petrovic Z. Lj. Saponjic, Z. 2009, ‘Plasma-induced Decolorization of Indigo-dyed Denim Fabrics Related to Mechanical Properties and Fiber Surface Morphology’, Textile research Journal, vol. 79, pp. 558-565. [24] [32] Uygun, A., Kiristi, M., Oksuz, L., Manolache, S. and Ulusoy, S. (2011) ‘RF hydrazine plasma modification of chitosan for antibacterial activity and nanofiber applications’, Carbohydrate Research, 346(2), pp. 259–265. Ramos, V., Runyan, D.A. and Christensen, L.C. (1996) ‘The effect of plasma-treated polyethylene fiber on the fracture strength of polymethyl methacrylate’, The Journal of Prosthetic Dentistry, 76(1), pp. 94–96. [33] Yoshinari, M., Wei, J., Matsuzaka, K., Inoue, T. (2009) ‘Effect of Cold PlasmaSurface Modification on Surface Wettability and Initial Cell Attachment’, International Journal of Biological, Biomolecular, 9 Agricultural, Food and Biotechnological Engineering, 3(10), pp. 507-511. [34] Lai, J.Y., Shih, C.Y. and Tsai, S.M. (1991) ‘Plasma deposition modified nylon 4 membranes for hemodialysis’, Journal of Applied Polymer Science, 43(8), pp. 1431– 1440. Downloaded by Cornell University Library At 07:02 16 May 2017 (PT) [35] Zanini, S., Freti, S., Citterio, A. and Riccardi, C. (2016) ‘Characterization of hydroand oleo-repellent pure cashmere and wool/nylon textiles obtained by atmospheric pressure plasma pre-treatment and coating with a fluorocarbon resin’, Surface and Coatings Technology, 292, pp. 155–160. [36] Zeronian, S.H. and Collins, M.J. (1989) ‘Surface Modification Of Polyester By Alkaline Treatments’, Textile Progress, 20(2), pp. 1–26. [37] Sun, D. and Stylios, G.K. (2006) ‘Fabric surface properties affected by low temperature plasma treatment’, Journal of Materials Processing Technology, 173, pp.172–177. 10