Investigation of the conformational changes of a conducting polymer in gas sensor active layers by means of polarization-modulation infrared reflection absorption spectroscopy (PM-IRRAS).
Polarization-Modulation Infrared Reflection Absorption Spectroscopy (PM-IRRAS) was employed to observe the changes in the molecular conformation of poly(2-phenyl-1,4-xylylene) (PPPX) films that occurred after exposure to organic solvent vapors. The PPPX films were supported on solid matrixes by casting, spin-coating, and Langmuir-Blodgett (LB) techniques. The results show that the polymer is sensitive to the solvent vapors, which affect some of the vibration dipole moments, as detected by PM-IRRAS. The sensitivity depends on the method employed to immobilize the polymer, with more significant changes in films formed using techniques that result in a less systematically organized conformation. This feature enables the use of surface vibration spectroscopy to detect organic solvent vapors and may be applied in an artificial nose.
Laboratory of Hybrid Materials, Federal University of São Paulo, Diadema, SP, Brazil. lcaseli@gmail.com
Luciano
L
Caseli
Jonas
J
Gruber
Rosamaria W C
RW
Li
Laura O
LO
Péres
D001713:Biphenyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D008968:Molecular Conformation; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013499:Surface Properties
D001713:Biphenyl Compounds; D005740:Gases; D011108:Polymers