A selective conductive polymer-based sensor for volatile halogenated organic compounds (VHOC)

Identification of Four Wood Species by an Electronic Nose and by LIBS

“…Poly(2-phenyl-1,4-xylylene)(PPPX), poly(4 -hexyloxy-2,5-biphenyleneethylene), (PHBPE), and poly(2-bromo-5-hexyloxy-p-phenylenevinylene) (BHPPV) were synthesized according to the literature procedures [15], [7] and [16], respectively.…”

“…We have recently described chemiresistive gas sensors, based on conductive polymers, for sensing several organic solvents [4], low-molecular-weight alcohols [5,6], and volatile halogenated organic compounds (VHOCs) [7] and also for determining alcohol content in automotive fuel [8]. An array of gas sensors connected to a pattern recognition software is known as electronic nose [9] and can analyse complex mixtures of volatile compounds.…”

Analytical Methods for Determining Automotive Fuel Composition

“…The reasons for using CPs for this purpose are that a huge number of different CPs can be synthesized, they respond to a wide range of volatile compounds and they operate at room temperature, which implies in low power consumption and, hence, portability. The most common CPs used for gas-sensing purposes are polypyrrole (De Melo et al, 2005), polythiophene (Chang et al, 2006), polyaniline (Anitha & Subramanian, 2003) and more recently also poly(pphenilenevinylene) derivatives (Benvenho et al, 2009) and poly-p-xylylenes (Li et al, 2008;Li et al, 2009). Their chemical structures are shown in Figure 1.…”

“…Their chemical structures are shown in Figure 1. Interestingly, although polyp-xilylene is known for its excellent insulating property, aryl-substituted derivatives become conducting upon doping and are highly stable to air and humidity, being very convenient for gas sensors (Li et al, 2008). The sensors usually consist of thin (1 -50 μm) doped polymer films deposited by spin-coating, drop-casting or other technique onto interdigitated electrodes.…”

“…The sensors usually consist of thin (1 -50 μm) doped polymer films deposited by spin-coating, drop-casting or other technique onto interdigitated electrodes. These, depending on the desired distance between digits can be obtained by several methods as, for instance, circuit printing (Li et al, 2008) and graphite line patterning (Venancio et al, 2008) Reversible changes in the electrical conductance of the CP films, upon exposure to volatile compounds, can be measured using a conductivity meter. The reasons for these changes remain not fully understood but may involve swelling of the polymer and also chargewww.intechopen.com transfer interactions caused by the penetrating vapours (Meruvia et al, 2007;Slater et al, 1992).…”