PROTONATION AND CHARGE-TRANSFER IN POLY-ANILINE - AN OPTICAL-ABSORPTION STUDY OF THE MIXED-SOLUTIONS

Interaction of polyaniline (PANI) with a protonating dopant, dodecylbe nzenesulfonic acid (DBSA), and an organic electron acceptor, pentadecy ltetracyanoquinodimethane (C(15)TCNQ), is studied in DMSO solutions, u sing optical absorption spectroscopy. Each of the two agents alone ind uces an absorption band at 417 nm, attributable to cation-radicals of PANI. Free carrier absorbance in the near-infrared is absent in the ca se of C(15)TCNQ. Moreover, the charge-transfer interaction between PAN I and C,,TCNQ suppresses a transition to the conductive state. When PA NI/C(15)TCNQ mixtures are aged, a new band neat 500 nm appears that ca n be attributed to an adduct of PANI and C(15)TCNQ. (C) 1997 Elsevier Science S.A.