Electrical and morphological characterisation of new ?-conjugated polymer films as gas sensors

The role of polymerfilms in sensor applications received recently an increasing deal of attention. In the framework of polymerfilm-based sensors, a considerable part of scientific interest has been devoted to humidity sensors. New?-conjugated systems have been investigated and results of the studies on poly(propargyl-alcohol) [PPOH] and poly(N,N-dimethylpropargylamine) [Pd-PDMPA] are here reported. SnCl2-PPOH and I2-PPOH show an electrical response towards relative humidity (r.h.) in the range 0-90%. The electrical response to r.h. variations of the HCl doped polymer (HCl-Pd-PDMPA) has been studied. Morphologicalcharacterisation was performed by Atomic Force Microscopy (AFM) and Scanning Tunneling Microscopy (STM) techniques on both the two polymeric systems in order to study: (a) the surface morphological variation during the chain growth, testing samples produced at different polymerisation reaction times (AFM) and (b) doped samples in order to estimate the influence of different dopants and different doping exposure times (STM and AFM).