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Mechanism of conductivity decay of polypyrrole exposed to water and enhancement of conductivity stability of copper(I)-modified polypyrrole

2001; Elsevier BV; Volume: 501; Issue: 1-2 Linguagem: Inglês

10.1016/s0022-0728(00)00510-6

1873-2569

Yu‐Chuan Liu, Bing‐Joe Hwang,

Analytical Chemistry and Sensors

The degradation of polypyrrole (PPy)-based films was examined in a 50% relative humidity and oxygen free atmosphere for 50 days. The results reveal that polymerization potential, modification of PPy with Cu(I), and treatment of PPy with water in preparation, demonstrate significant influences on the conductivity and the corresponding stability of PPy. PPy prepared at an over-oxidizing potential and treated with water for 0.5 h exhibits a serious decrease in conductivity by about 93%, whereas the Cu-modified PPy becomes more stable. This is attributed to electron transfer from Cu to the N+ of PPy. The concept of fixed and removable water adsorbed on PPy is introduced to explain the experimental results. Also, an aging mechanism involving the interaction between H2O and PPy is proposed to explain the decay in conductivity.