The role of cross-linking structures to the formation of one-dimensional nano-organized polyaniline and their Raman fingerprint

In the present work, the resonance Raman, UV–vis–NIR and scanning electron microscopic (SEM) data of nanorods (about ∼300 nm in diameter) and nanofibers (about ∼93 nm in diameter) of PANI are presented and compared. The PANI samples were synthesized in aqueous media with dodecybenzenesulfonic acid (DBSA) and β-naphtalenesulfonic acid (β-NSA) as dopants, respectively. The presence of bands at 578, 1400 and 1632 cm−1 in the Raman spectra of PANI-NSA and PANI-DBSA shows that the formation of cross-linking structures is a general feature of the PANI chains prepared in micellar media. It is proposed that these structures are responsible for the one-dimensional PANI morphology formation. In addition, the Raman band at 609 cm−1 of PANI fibers is correlated with the extended PANI chain conformation.