Study on sensing properties of chitosan-polyethylene oxide-exfoliated graphite based toluene sensors

Abstract

Chitosan was used as a material to fabricate film sensor because of its structure and properties where it consists of amino group which has free electron. In this study, chitosan was added with polyethylene oxide and exfoliated graphite to study the electrical properties toward wet air, dry air and toluene. Chitosan powder was dissolved in 2.00 v/v% of acetic acid to form chitosan solution. Then, the chitosan solution was added with polyethylene oxide and exfoliated graphite based on the ratio needed. The composition of the materials was varied and fabricated on gold plated printed circuit board by using electrical deposition technique. Chitosan/polyethylene oxide/exfoliated graphite matrix films were prepared to observe the effect of exfoliated graphite concentration on microstructure, electrical conductivity, and sensing properties of the films. The chitosan/polyethylene oxide/exfoliated graphite film was prepared with various concentration of exfoliated graphite to obtain the best concentration of exfoliated graphite to achieve the excellent properties of the films. The SEM technique was employed to analyse the micro- structure of the prepared chitosan/ polyethylene oxide / exfoliated graphite. The FT-IR was used to analyse the functional groups existence in the chitosan/polyethylene oxide/exfoliated graphite films. From the result obtained, this project successfully proved that the addition 0.4w/v % of exfoliated graphite onto chitosan/polyethylene oxide film has improved the sensing properties of the films. The chitosan/polyethylene oxide/exfoliated graphite films have better response, sensitivity and stability compare to chitosan/polyethylene oxide films.