Methanol sensors based on the conductive polymer composites from polypyrrole and poly (vinyl alcohol)

Abstract Methanol sensors based on polypyrrole-poly(vinyl alcohol) (PPy-PVA) composite films were prepared electrochemically with various charges, ranging from 0.05 to 0.20 C. The sensing abilities, including sensitivity, response time and recovery time, to various methanol-vapor concentrations, ranging from 15 to 218 mg l−1, were investigated. The methanol-sensing ability was dependent on the electropolymerization charge and was better if a lower charge was applied. A sensitivity of 9.70 mΩ mg l−1, about nine times the sensitivity of the pristine PPy sensor, was measured by the PPy-PVA sensor prepared at 50 mC.The PPy-VA composite sensors responded as quickly as 33 s in a methanol concentration of 218 mg l−1. PVA loading in the electrolytic solution showed an effect on the sensitivity of the sensor and exhibited an order of 7.5 g l−1 >5.0 g l−1 > 10.0 g l−1> 1.0g l−1> pure PPy. However, we also found that the stability of the PPy-PVA composite sensor under exposure to methanol vapor was poorer than that of the pure PPy sensor.

[1]  P. Bartlett,et al.  Conducting polymer gas sensors part I: fabrication and characterization , 1989 .

[2]  Effect of doping anions in polypyrrole gas sensors , 1993 .

[3]  A. El Hadri,et al.  Study of the action of gases on a polypyrrole film , 1990 .

[4]  A. Fukuda,et al.  Coagulation of polymer–Cu2+ complexes in polymer films and its application for producing semiconducting CuI surface layers , 1979 .

[5]  Paolo Bruschi,et al.  Sensing properties of polypyrrole-polytetrafluoroethylene composite thin films from granular metal-polymer precursors , 1992 .

[6]  Philip N. Bartlett,et al.  Conducting polymer gas sensors part II: response of polypyrrole to methanol vapour , 1989 .

[7]  L. Yucheng,et al.  Characterization of a chemoresistor pH sensor based on conducting polypyrrole , 1994 .

[8]  Ş. Süzer,et al.  A conducting composite of polypyrrole II. As a gas sensor , 1995 .

[9]  G. Blasquez,et al.  Behaviour of electroactive polymers in gaseous oxidizing atmospheres , 1988 .

[10]  G. Bidan,et al.  Electroconducting conjugated polymers: New sensitive matrices to build up chemical or electrochemical sensors. A review☆ , 1992 .

[11]  R. Waltman,et al.  Conductive composties form poly(vinyl chloride) and polypyrrole , 1984 .

[12]  G. Street,et al.  Conductive composites from polyvinyl alcohol and polypyrrole , 1984 .

[13]  Julian W. Gardner,et al.  Electrochemical deposition of conducting polymers onto electronic substrates for sensor applications , 1990 .

[14]  Alan Hooper,et al.  Conducting polymer gas sensors , 1986 .

[15]  P. Bartlett,et al.  Conducting polymer gas sensors Part III: Results for four different polymers and five different vapours , 1989 .

[16]  Seizo Miyata,et al.  Highly Transparent and Conducting Polypyrrole–Poly(vinyl alcohol) Composite Films Prepared by Gas State Polymerization , 1986 .

[17]  Photoconductivity of poly(vinyl alcohol) films with Fe3+ complexes and ESR study of their structures , 1981 .

[18]  W. Ko,et al.  Phthalocyanine Langmuir-Blodgett film microsensors for halogen gases , 1990 .

[19]  Andrew P. Monkman,et al.  Polyaniline thin films for gas sensing , 1995 .

[20]  T. Hanawa,et al.  Gas sensitivities of polypyrrole films to electron acceptor gases. , 1989 .