Preparation and properties of vapor detector arrays formed from poly(3,4-ethylenedioxy)thiophene-poly(styrene sulfonate)/insulating polymer composites

Poly(3,4-ethylenedioxy)thiophene-poly(styrene sulfonate) (PEDOT-PSS) was used as the conductive component in a matrix of chemically different insulating polymers to form an array of vapor detectors. Such composites produced larger relative differential resistance responses when exposed to polar analytes than did the corresponding carbon black filled polymer composite detectors. However, the PEDOT-PSS composites produced smaller responses than carbon black composites when exposed to nonpolar analytes. The resolving power of a PEDOT-PSS detector array was compared to that of a carbon black composite array for a broadly construed set of organic vapors. The PEDOT-PSS array exhibited better, on average, discrimination between pairs of polar analytes and polar/nonpolar analytes than did the carbon black composite array. The carbon black composite array out-performed the PEDOT-PSS array in discriminating between nonpolar compounds. The addition of PEDOT-PSS composites to an array of carbon black composite detectors therefore can produce improved overall discrimination in a vapor sensor system when used in tasks to differentiate between of a broad set of analyte vapors.