Deposition and application in gas sensors of thin films of a bridged chain dialkoxy PPV derivative

Films of a dialkoxy poly(p-phenylenevinylene) (PPV) derivative bearing a bridged chain dialkoxy substituent on the aromatic rings (Bridged Dialkoxy PPV: BDA-PPV) were prepared via solvent casting and Langmuir-Blodgett (LB) techniques for applications in gas sensing devices. A description of the LB deposition of the sensing layers starting from an equimolar mixture of the polymer and arachidic acid is reported. Silicon substrates equipped with gold interdigitated electrodes have been used for both deposition procedures. In particular, the samples deposited by solvent casting evidence variation of the electrical conductivity when exposed to NO2 oxidising agent at a working temperature of about 75 degreesC. They also exhibit selectivity towards NO2 with respect to other different gases like carbon monoxide, nitrogen monoxide, ammonia and sulphur dioxide. On the contrary, LB multilayers, containing arachidic acid, have not shown any sensitivity towards all analysed gases. (C) 2002 Elsevier Science B.V. All rights reserved.