Interactions between CO and Poly(p-phenylene vinylene) as Induced by Ion-Exchanged Zeolites

The effects of zeolite type, ion-exchanged level, and ion type on the electrical conductivity responses of poly(p-phenylene vinylene) (PPV), doped poly(p-phenylene vinylene) (dPPV) and zeolite composites under CO exposures were investigated. The electrical sensitivity of dPPV/Cu(+)-ZSM5(Si/Al = 23) system shows a negative sensitivity value of −0.154, while the Na(+) system gives a positive sensitivity of 1.48. Based on FTIR and TPD data, the positive response of PPV/Na(+)-ZSM5 stems from the CO molecules acting as a secondary dopant. On the other hand, the negative response of PPV/Cu(+)-ZSM5 originates from the fact that CO molecules are selectively adsorbed on Cu(+) sites rather than C(+) sites of doped PPV.