Chemical Vapor Detection Using Parent Polythiophene Nanofibers

The thin conducting nanofiber polythiophene films can be synthesized on plastic substrates directly from the polymerization and the spontaneous dedoping phenomenon can be leveraged to fabricate a reversible and selective detector for NO2,Cl2,SO2 has been demonstrated. The result of X-ray photoelectron spectroscopy, FT/IR, and nonaqueous electrochemistry before and after the vapor exposure/UV cycle reveals no irreversible reaction. The increase in conductivity in polythiophene films suggests that polymer is in partially reduced state and is chemically doped by these oxidizing vapors. The conductivity decreases in the case of other conducting polymers when, exposed to NO2,Cl2,SO 2 consistent with oxidation of polymer resulting in an irreversible resistance response.