Fibers and Polymers 2011, Vol.12, No.8, 1037-1041 1037 Effect of Various Shapes of Zinc Oxide Nanoparticles on Cotton Fabric for UV-blocking and Anti-bacterial Properties W. Sricharussin 1,2 , P. Threepopnatkul 1,2 * , and N. Neamjan 1 1 Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, Thailand 2 Center of Excellence for Petroleum, Petrochemicals, and Advanced Materials, Chulalongkorn University, Bangkok 10330, Thailand (Received February 9, 2011; Revised April 27, 2011; Accepted April 30, 2011) Abstract: Various shapes of ZnO - multi-petals, rod and spherical - were prepared and then applied on cotton fabric for UV- blocking and anti-bacterial properties. The ZnO particles were investigated by XRD and SEM. The as-prepared suspension was applied onto cotton fabrics via the pad-dry-cure process at 150 o C. The characteristics of the fabric coating were investigated by SEM, XRD and Atomic Absorption Spectroscopy (AAS). The UV-blocking effectiveness was measured with a UV-Vis spectrophotometer whilst the antibacterial activity was determined using the AATCC 147 method. The results of XRD and SEM on the ZnO powders show that we can produce various shapes of ZnO. The investigation by SEM and AAS clearly revealed that ZnO was effectively deposited on the cotton surface and that the adhesion was retained after washing ten cycles. The sphericals-shaped ZnO and multi-petals shaped ZnO coated fabrics show excellent UV-blocking properties. All treated samples showed good antibacterial activity against Staphylococcus Aureus. The shape of ZnO shows no considerable effect on antibacterial properties. Keywords: Zinc oxide, Cotton, UV-blocking, Antibacterial Introduction The application of nanotechnology in the textiles area has attracted considerable interests in recent years [1-3]. This is due to the fact that nanoparticles have high surface area and can provide high durability for fabrics. Various research works on the application of UV-blocking treatment to fabrics were conducted. Among the metal oxide nanoparticles, titanium dioxide has been widely studied as a coating material for textile fabrics to provide functions such as antibacterial activity [4], UV protection [4,5] and self-cleaning [6-8]. Zinc oxide (ZnO), a semiconductor with wide bandgap of 3.37 eV, has been considered as a promising nanomaterial for a wide range of applications such as surface acoustic wave filters, photodetectors, gas sensors, and UV-blocking [9]. Some shapes of nano ZnO has been synthesized and applied on cotton fabrics to achieve excellent UV-blocking property [10-12]. Antibacterial agents are of relevance to a number of industrial sectors including food, synthetic textiles, packaging, healthcare, as well as construction. They can be classified into two types, organic and inorganic. The inorganic materials, metal oxides such as TiO 2 , ZnO, MgO and CaO are of particular interest as they are not only stable under harsh process conditions but also generally regarded as safe materials to human beings and animals [13,14]. It was determined that a fabric treated with nano-TiO 2 could provide effective protection against bacteria, due to the photocatalytic activity of TiO 2 . Nano-ZnO also provides effective photocatalytic property and imparts antibacterial activity to textiles [15]. Several techniques were employed to produce nano-ZnO and the sol-gel route stands out as simple, low cost and effective. However, controlling the morphology of nanoparticle growth is a very important task in nanotechnology research. The range of nanostructures of ZnO - wires, rods, belts, dumbbells, tubes, multi-petals - has attracted research activity on the roles of shape and size for their applications in functional materials [16]. In this paper, we prepared three shapes of nano-ZnO: ZnO multi-petals [17], ZnO rods [18] and ZnO spherical particles [19]. All ZnO suspension were applied onto cotton fabrics via the pad-dry-cure process at 150 o C. The UV-blocking and anti-bacterial properties of various shapes of ZnO on cotton fabric were investigated. Experimental Procedure Preparation of Multi-petals ZnO Suspension 0.2195 g (1 mmol, the final concentration is 0.02 mol/l) Zinc acetate Zn(CH 3 COO) 2 ·2H 2 O and 0.5625 g β-CD (0.5 mmol, the final concentration is 0.01 mol/l) were dissolved in 40 ml of water; after magnetic stirring for 30 min, 10 ml of NaOH solution (1 mol/l) was added drop-wise. White cloudy precipitate soon appeared, as the NaOH was gradually added, the solution turned clear again. After the temperature was increased to 90 o C by an oil bath, white precipitates appeared which indicated that the ZnO was formed. The solution was kept at this temperature for 1 h and then cooled to room temperature. *Corresponding author: poonsubt@yahoo.com DOI 10.1007/s12221-011-1037-9