poster bayat tork mina

The International Istanbul Textile Congress 2013 May 30th to June 1th 2013, Istanbul, Turkey

1

INCORPORATION ANTIBACTERIAL NANOFIBROUS LAYER IN SPROT CLOTHING

Mina. Bayat tork1, Elmira. Hadipour Goudarzi2, Maryam Yousefzadeh2, and Masoud. Latifi2

1,2Textile Engineering Department, Amirkabir University of Technology, Tehran, Iran

[email protected]

Abstract: In this study antibacterial PVA electrospun nanofibers have been successfully prepared applying different effective electrospinning techniques. For improving the antibacterial properties of the cloth, the nano-silver particles (AGNPS) have been used and applied to cotton fabric. The effect of applied voltage, solution feed rate, distance and concentration on the morphology and diameter of nanofibers were investigated in order to obtain optimum electrospinning conditions. The three different electrospinning methods that were used, are conventional electrospinning, Co-electrospinning and Core-Shell one. The antibacterial activity of cotton fabrics that were coated with nanofibrous mats were evaluated against Gram-negative bacteria Escherichia coli. It was concluded that prepared nanocomposites nanofibrous cloth, due to large surface area, excellent antibacterial properties, porosity and flexibility have potential for any antibacterial applications such as sport-textile, bio-textile, wound healing, underwear clothing, and so many others. Keywords: PVA Nanofibers, Antibacterial Clothing, Core-Shell Electrospinning, Co-Electrospinning

1. Introduction Electrospinning is an effective process, utilizing electrostatic forces for fabrication non-woven fibrous mats. Electrospinning process due to its uniqe properties, is widely used in many fields such as protective clothing, biomedical clothing, tissue engineering, drug delivery and etc.

A typical electrospinning setup include syring pump, high voltage source and a grounded collector. in this method fibers in micro or nano scale were obtained by applying electrical charge to a polymer solution. various parameters influence characteristics of electrospun nanofibers such as solution concentration, applied voltage, feed rate, solvent properties(surface tention,viscosity), distance between capillary tip and collector [1].

In recent years, the design of antibacterial clothing has attracted much interest. Textile fabrics especially sport clothing and biomedical clothing due to large surface areas and the ability to retain moisture make them convenient for bacterial growth. therefore many research have been done for preparation antibacterial textile material. Because electrospun nanofibers have high porosity and a very small pore size, they have a larger specific surface area [2]. Non-woven mats made of such electrospun fibers show great potential for antibacterial application.

Many studies have been done in filed of electrospinning of PVA with nanoparticles especially silver nano particles. The PVA/Ag composite nanofibrous wound dressing material was successfully prepared by electrospinning a PVA/AgNO3 aqueous solution into nonwoven web[3]. Nano-fibrous mats have been successfully prepared by electrospinning of the blend solutions of cationic cellulose derivatives (PQ-4) and polyvinyl alcohol (PVA)[2].

It is well known,that silver nanoparticles posses antibacterial properties to control infections. they are widely used due to their uniqe properties as antibacterial agent against microorganism. Textile materials containing silver nanoparticles have recently found many applications in different fields such as biomedical, sport clothing, wound dressing and etc [4,5].

Current research is mainly focused on investigating some of the methods of electrospinning technique, which have the ability to incorporate the Silver nanoparticles into nanofibrous mat and therefore in sport clothing.


2

2. Experimental 2.1 Materials and preparation PVA, (Mw 72,000) was purchased from Merck chemical Co, emulsion solution of silver nanoparticles (4,000ppm particle size of about 50nm)was obtained from Nanofanavaran e kasra company, to prepare the polymer solutions, distilled water was used as a solvent and all of the solutions applied on the knit weave cotton fabrics . 2.2 Electrospinning PVA solutions and optimization In this study, two PVA solution concentrations (6% and 12% w/v) were prepared. To Prepare 6% and 12% PVA composite solution concentrations; 1.2 gr and 0.6 gr of PVA powder were dissolved in the solvent consist of 7.5 cc silver nanoparticles solution and 2.5 cc distilled water, respectively. 2.3 Electrospinning conditions To received to optimum conditions and prepare nanofibers with out any defects; it was necessary to be done studies in different electrospinning conditions And therefore, solution concentration, applied voltage, distance and solution feed rate were found in the optimum conditions..

2.4 Different methods of producing nanofibers containing silver nanoparticles In this study, three different methods were used for preparing nanofibers. These methods consist of: the conventional electrospinning, co-electrospinning and core-shell one. At the first method, 12% PVA solution concentration consist of silver nanoparticles was electrospuned conventionaly. The second method was similar to the first method except that emulsion silver nanoparticles solution was sprayed on the fabric in front of electrospinning of the composite solution. At the third method, with use of the 6% and 12% composite polymer solution as the shell and core respectively, core-shell electrospinning was done to produce the core-shell nanofibers. 2.5 Measurment and characterization To determine the optimal producing conditions nanofiber, SEM images were taken from the samples and nanofiber diameter of each samples was measured with Image J software. After the preparation of the samples according to the three mentioned methods; antibacterial test was performed . In this investigation, AATCC100 standard that is a quantitative method was used.

3. Results & Discussion In our experiment the electrospun PVA/Ag nano particles(AgNPs) fiber webs were prepared by three different methods. At First in order to obtain optimum electrospinning conditions, the effects of concentration, applied voltage ,distance and feed rate on the morphology and diameter of the electrospun PVA/AgNPs were investigated. Table (1) shows the different conditions that applied for prepration of electrospun fiber webs. it is observed that the average diameter of nanofibers increased with increasing concentration of solution from 12% to 15%.

Table 1. different electrospinning conditions

Voltage(Kv) Distance (cm) Feed rate (ml/h)

concentration (%w/v)

12, 16, 20 8, 14, 20 0.13 12

12, 16, 20 8, 14, 20 0.25

12, 16, 20 8, 14, 20 0.13 15

12, 16, 20 8, 14, 20 0.25


3

3.1 Concentartion Concentration of solution is an important and critical parameter in the electrospinning process because some characteristics of solution is related to concentration of solution. Surface tention and viscosity of the polymeric solution are a function of solution concentration. high or low concentration of solution causes the process to be faced with problem. Therefore an optimum value should be selected [1]. Based on reports, around optimum concentration of the solution, the diameter of nanofibers increases with increasing concentration of solution [1]. in this study, the finer fibers were obtained at concentration of 12%. 3.2 Voltage To examine the effect of voltage on diameter of electrospun fiber, different voltages 12, 16, 20 Kv were applied. under similar conditions, the impact of voltage on the diameter of electrospun fiber was not clear. but it is observed that the average diameter of fibers in 16 Kv was less than other applied voltage. according to work carried out by others, it is obvious optimal voltage for a certain polymer is required for generation nanofibers without defects[1]. 3.3 Distance the distance between capillary tip and collector can also effect the morphology and fiber diameter. the effect of distance between capillary tip and collector on the diameter of nanofiberous is not regular. in this work, electrospinning at three distances (8,14,20 cm) were carried out. The results showed that fibers with smaller diameters are achieved at 8cm. 3.4 feed rate feed rate determine amount of solution that removed from syring. fiber diameter increase with increasing feed rate. in addition, with increasing feed rate, there is possibility to see defects such as bead. according to what mentioned ,12%, 16 Kv, 8 cm, 0.13 ml/h were selected as optimum conditions for electrospinning. Figure (1) shows the the scanning electron microscope images of the PVA/AgNps electrospun fibers.

Figure 1. solution concentration:12%, applyed voltage: 16 Kv, feed rate:0.13 ml/h and left to right distance equal 14 ,8,

20 cm respectively

3.5 The antibacterial efficacy of treated cotton fabrics In this study,the antibacterial properties of cotton fabrics that were coated with PVA/AgNPs nanofibrous mats against gram negative bacteria, Escherichia-coli were evaluated by the standard quantitatively testing method (AATCC 100)[6]. rectangular pieces of fabric (4*2 cm) of treated cotton fabric and control sample( without AgNPs ) were prepared and they were sterilized in the autoclave. bacteria were cultured in nutrient broth and heat for 24 h in 37 ̊c.E coli suspension was added to each fabric-containing petri dishese. After incubation, add 100 ml of neutralizing solution to petridishes containing untreated control samples and to petri dishese containing treated test samples. then incubate all plates for 48 h at 37 ̊c.after that the colonies grown on the plates were counted.


4

Therefore the percentage reduction of bacteria was calculated by equation(1). R=100(B-A)/B (1)

Where: R=% reduction A=the number of bacteria recovered from the inoculated treated test specimen swatches over the desired contact period. B=the number of bacteria recovered from the inoculated treated test specimen swatches immediately after inoculation. (at “0” contact time) Picture of plates shows antibacterial property of coated cotton fabrics with nanofibrous mats.

4. Conclusion In this study antibacterial PVA/silver nanoparticles nanofibers have been successfully prepared using three different methods. results indicated With increasing the solution concentration, distance and feed rate, average nanofiber diameter was increased. While the changes in voltage did not lead to specific trend in the nanofiber diameter. Optimum conditions for preparing finer nanofiber with out any defect were as follows: solution concentration, distance, applyed voltag and feed rate equaled 12%, 8cm, 16 Kv and 0.13 ml/h respectively. for all of the samples Antibacterial test result, showed antibacterial property.

5. Referencing [1] Travis J, Sill; Horst A, von Recum.: Electrospinning: Applications in drug delivery and tissue engineerin,

Biomaterials, 29. (2008) 1989e2006 [2] Baoquan, Jia.; Jinping, Zhou.; Lina, Zhang.: Electrospun nano-fiber mats containing cationic cellulose

derivatives and poly (vinyl alcohol) with antibacterial activity, Carbohydrate Research, 346. (2011) 1337–1341

[3] Kyung Hwa Hong.: Preparation and Properties of Electrospun Poly(vinyl alcohol)/Silver Fiber Web as Wound Dressings, Published online in Wiley InterScience (www.interscience.wiley.com)

[4] Messaouda, M and etal.: Photocatalytic generation of silver nanoparticles and application to the antibacterial functionalization of textile fabrics, Journal of Photochemistry and Photobiology A: Chemistry, 215. (2010) 147–156

[5] Singh, M; and etal.: Nanomater. Bios, 3. (2008) 115 [6] American Association of Textile Chemists and Colorists.: AATCC Test Method 100-2004 Antibacterial Finishes on Textile Materials, N.C., USA, 2011

poster bayat tork mina

Business