Polyaniline Nanofiber Gas Sensors:  Examination of Response Mechanisms

Using a new interfacial polymerization method for the synthesis of polyaniline nanofibers, we have developed nanofiber sensors and compared them to conventional polyaniline sensors. Five different response mechanisms are explored: acid doping (HCl), base dedoping (NH3), reduction (with N2H4), swelling (with CHCl3), and polymer chain conformational changes (induced by CH3OH). In all cases, the polyaniline nanofibers perform better than conventional thin films. Their high surface area, porosity and small diameters enhance diffusion of molecules and dopants into the nanofibers.