Sulfonic Acid Doped Thermoreversible Polyaniline Gels. 3. Structural Investigations

Abstract

The surface morphology of the thermoreversible polyaniline (PANI) gels prepared with dinonylnaphthalenesulfonic acid (DNNSA), dinonylnaphthalenedisulfonic acid (DNNDSA), (±)-camphor-10-sulfonic acid (CSA), and n-dodecyloxy sulfonic acid (DOSA) are studied using atomic force microscopy (AFM) for 15% PANI concentration (w/w). The AFM study clearly reveals the formation of lamellar morphology in the gel. X-ray scattering experiments of these gels also support the lamellar structure formation, and the lamellar thickness measured from it remains invariant with composition for the PANI−DNNSA and PANI−DNNDSA systems. In PANI−CSA and in PANI−DOSA systems the lamellar thicknesses vary with PANI concentration. Both X-ray diffraction and electron diffraction experiments on the gels of different compositions of PANI−DNNSA and PANI−DNNDSA systems indicate new spacings of lower dhkl values which are invariant with composition. Similar observations are also found in PANI−CSA and PANI−DOSA systems. These results indicate...