3-Mercapto-1,2-propanediol-substituted polyaniline/Ag nanocomposites prepared by concurrent reduction and substitution chemistry

PANI/Ag composite particles were prepared through two-step reaction process comprising the reduction of the PANI backbone by the substitution of 3-mercapto-1,2-propanediol (MPD) and the simultaneous redox reaction between AgNO3 and MPD-substituted PANI. In order to investigate the effects of MPD and AgNO3 on the oxidation state of PANI, MPD and AgNO3 were sequentially added into PANI/NMP solution, and the oxidation state of PANI was investigated by time-dependent UV–vis spectra. On the basis of UV–vis spectroscopic study, MPD-substituted PANI/Ag composite was prepared through following two steps: (1) treating PANI particles with MPD (reduction of PANI backbone); (2) adding AgNO3 solution to MPD-substituted PANI (re-oxidation of PANI backbone). The molar ratio of AgNO3 to aniline unit in the PANI chains was varied from 1:16 to 1:1. The substitution of PANI with MPD and the formation of PANI/Ag composite were characterized by FT-IR, XRD and EDX. The morphologies of PANI/Ag composites were investigated by TEM.