1014 ISSN 1229-9197 (print version) ISSN 1875-0052 (electronic version) Fibers and Polymers 2018, Vol.19, No.5, 1014-1023 Self-cleaning Properties of Nylon 6 Fabrics Treated with Corona and TiO 2 Nanoparticles under Both Ultraviolet and Daylight Irradiations Fatemeh Emami 1 , Shahla Shekarriz 2 * , Zahra Shariatinia 1 * , and Zahra Moridi Mahdieh 2 1 Department of Chemistry, Amirkabir University of Technology (Tehran Polytechnic), Tehran 15875-4413, Iran 2 Color and Polymer Research Centre, Amirkabir University of Technology (Tehran Polytechnic), Tehran 15875-4413, Iran (Received November 27, 2017; Revised February 25, 2018; Accepted February 28, 2018) Abstract: Nylon 6 fabric with self-cleaning properties was prepared by corona discharge pre-treatment and coating with TiO nanoparticles (NPs) using pad-dry-cure technique. The self-cleaning property was studied by discoloration of methylene blue (MB), ketchup, tea and coffee stains from the corona+TiO treated nylon-6 fabric. Color difference (ΔΕ ), reflectance (R) and K/S of MB stain were investigated by diffuse reflectance spectrophotometry. The MB stain was almost completely removed from the corona+TiO treated nylon surface after 24 h under UV light/daylight irradiation. Both of these phenomena (corona and TiO ) led to an increase in the discoloration of stains under UV and daylight irradiations. The EDS analysis showed an increase in the concentration of deposited TiO NPs coating after corona treatment. The FE-SEM images revealed that the surface of nylon 6 was coarser after the corona treatment. Also, the FE-SEM micrographs exhibited that a uniform layer of TiO NPs was formed on the corona treated nylon fabric. The corona+TiO treated nylon illustrated antibacterial activity against E. coli and B. subtillis microorganisms. The EDS and FE-SEM analysis confirmed that after 5 washing cycles, the amount of TiO NPs was higher on the surface of corona+TiO treated nylon than that of the fabric only treated with TiO without corona pretreatment. This result justifies that the corona+TiO treated nylon fabric with appropriate self-cleaning property can be applied cost-effectively in the textile industry. Keywords: Self-cleaning, TiO nanoparticles, Corona, Nylon 6, UV/daylight, Surface modification Introduction Producing textiles with self-cleaning properties is a significant issue in the textile industry. Hydrophilic self- cleaning is known as the photocatalytic effect because of inducing catalytic activities on a substrate surface. The photocatalytic materials decompose dirt, contaminants, pollutants or microorganisms by photoreduction and photo- oxidation chemical reactions in the presence of light [1]. Among photocatalysts, nanocrystalline TiO 2 attracts much attention due to its high activity, chemical stability and nontoxicity [2]. In recent years, the TiO 2 photocatalyst is widely used in water and air purification [3], deodorization [4], self-cleaning process [5] and anti-bacterial materials [6]. There are several studies that confirm the high efficacy of anatase titania crystalline form of TiO 2 with photoactive properties compared with rutile and brookit titania [7,8]. The anatase titania has a high surface area with high degree of crystallinity. Therefore, the anatase TiO 2 has been applied for possessing self-cleaning property on glass [9], solar panel [10], textile [11,12] and paints [13]. In recent decades, titanium dioxide has been known as one of the best options for photocatalytic applications such as self-cleaning. There are many reports for modifying textile substrates with photocatalytic TiO 2 nanostructures by various coating methods [14,15]. Recently, several studies have been focused on improving adhesion between TiO 2 NPs and the substrate by chemical [16,17] and physical pretreatment processes [17,18]. The conventional methods of surface modification have a great environmental impact because of possessing complicated processes. Corona discharge is a non-polluting technique for surface modification at the atmospheric pressure. Corona treatment uses low temperature corona discharge plasma to impart changes in the properties of a surface. During the treatment, activated species such as ions, electrons and excited oxygen molecules react with the polymer surface [19]. These radicals lead to increasing the active sites for adhesion on the polymeric surface of textile fabrics [20]. In several studies, it has been reported that the surface adhesion of textile fabrics has been improved by both chemical and physical effects of plasma pretreatment [21- 23] due to introducing several chemical functional groups such as -CO and -COO groups [24]. The chemical changes of corona discharge were caused by the air or oxygen gas oxidation [25,26]. Furthermore, the physical properties of fabric surface are varied as a result of creating surface roughness at the micro- and nano-scales [27]. Nylon 6 fabric is an interesting textile material because of its excellent properties including durability, outstanding abrasion resistant, easy care features, wrinkle-proof and high tensile strength [28]. To the best of our knowledge, the self- cleaning properties of the nylon-6 fabric treated with corona and TiO 2 NPs under UV/day light have not been reported in literature. In the present work, corona discharge pretreatment was employed to modify nylon 6 fabrics in order to activate them for improving their self-cleaning and antibacterial *Corresponding author: shahlashekarriz@aut.ac.ir *Corresponding author: shariati@aut.ac.ir DOI 10.1007/s12221-018-1025-4