International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 04 Issue: 08 | Aug -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 534 DEVELOPMENT OF POLYANILINE GRAFTED CHITOSAN SENSOR FOR DETECTION OF AMMONIA & ETHANOL VAPOUR Shekhar Pandharipande 1 , Subodh S. Bankar 2 1 Associate Professor 2 MTech 4 th Sem Chemical Engineering Department of Chemical Engineering, Laxminarayan Institute of Technology, Rashtrasant Tukdoji Maharaj Nagpur University, Nagpur City, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - The use of conducting polymers as sensing elements in electrochemical or chemical sensors is a center of attraction due to their good sensitivity in changing electrical and optical properties when exposed to different types of gases and liquids. The demand for gas sensor is increasing day by day due to requirements in air quality monitoring, safety of processes & medical applications. Polyaniline is one of the most commonly used polymer and its characteristics as sensor can be enhanced by adding other material to form composite. Chitosan has promising characteristics to be used as biosensor, vapor sensor, electrochemical sensor etc. The present work explores the possibility of development of electrochemical gas sensor by using conducting polyaniline and chitosan base composite film using cloth and paper substrates. Six electrodes, three each of cloth and paper base using PANi powder and PANi–gf-Ch film as sensing elements have been developed. These electrodes are evaluated for their sensitivity for ammonia and ethanol vapor using electrochemical cell. Based on the result & discussion, it can be said that the sensitivity of PANI-gf-Ch composite film electrode showed higher current output than using only PANI powder coated electrode. The best response in ammonia sensing, is obtained by the filter paper based substrate electrode PPCh1 of the magnitude of 0.15 mA, followed by cloth based film electrode CPCh1 as 0.04. Similarly CPCh1 and PPCh1 are observed to be effective in sensing ethanol with good current output when compared with electrodes like CP1, C1, P1 and PP1 which do not contain chitosan. Key Words: Polyaniline grafted Chitosan film Electrodes, Electrochemical sensor, filter paper, cloth strips. 1. INTRODUCTION Today, the use of conducting polymers as sensing elements in electrochemical or chemical sensor is a centre of attention due to their good sensitivity in changing electrical and optical properties when exposed to different types of gases and liquids. The demand for gas sensors is increasing day by day due to requirements in air quality monitoring, safety of processes and medical applications. These conducting polymers can be synthesised easily by means of chemical or electrochemical methods. The sensitivity at room temperature adds to the sensorǯs advantage and is importance particularly as ammonia or alcoholic compounds are used in different applications in process industries. Polyaniline is one of the most commonly used conducting polymers due to its unique electrical properties, atmospheric stability and intrinsic redox reaction. Polyaniline is also used in different applications such as light emitting diodes, rechargeable batteries and photovoltaic cells, anticorrosive coating material etc. However the disadvantages of these conducting polymers are their low processing ability, poor chemical stability and mechanical strength due to its thinness. There is an approach for improving the mechanical strength and characteristics of sensors by adding organic or inorganic material to form composites. Chitosan can be synthesized by using seafood waste like crab & shrimp. Chitosan has promising characteristics to be used as biosensor, vapour sensor, volatile organic compound sensor, electrochemical sensors and many more. Chitosan has been used as a biosensor due to its excellent film forming properties and ability to retain its original properties. Apart from that, chitosan is low cost because it is synthesized from waste and is a natural reproducible polymer. Another important feature is that, chitosan can be effective in sensing vapour at room temperature. 1.1 Literature Survey Sadanand Pandeya et al studied and reported in review paper some of the current breakthrough developments in the area of gas sensors based on polyaniline (PANI) nanocomposite. PANI-based sensor experiences some important disadvantage of poor reproducibility, selectivity & stability. In order to overcome this restriction PANI was functionalised or incorporated with nanoparticles (NPs), carbon compounds and shows outstanding properties for gas sensing. Herein, author summarize recent advantages in PANI nanocomposite preparation, sensor construction, and sensing properties of various PANI nanocomposites based gas/vapor sensors, such as NH3, H2, HCl, NO2, H2S, CO, CO2, SO2 & LPG.[1] Li Huixia, et al investigated the gas sensing properties of hydroxyapatite based composites which were prepared by mixing different contents of conductive polymers: polypyrrole and polyaniline (PAni). The compositions, microstructures and phase constitutions of polymer/HAp composites were characterized, and the sensing properties