Polyaniline nanocomposites via in situ emulsion polymerization based on montmorillonite: Preparation and characterization

Abstract

Polyaniline nanocomposites were prepared via in situ emulsion polymerization in the presence of Na+ montmorillonite (Na+MMT). For achieving this purpose the clay was organophilized to (MMT-CTA) form using cetyltrimethyl ammonium bromide (CTAB). The X-ray diffraction (XRD) demonstrated that the basal space of Na+-montmorillonite increased after the organophilization from 11.21 to 19.35 Å. Polyaniline/montmorillonite (PAn/MMT) nanocomposites were prepared by intercalating the emulsion of aniline monomer with treated organically layers of (Na+-MMT) using ammonium peroxydisulfate (APS) as an initiator. Furthermore aniline hydrochloride (AnHCl) was used as a modifier and monomer to prepare PAn/H+MMT nanocomposites by cation exchange of the anilinuim moiety with the sodium ion inside the basal spaces which enlarged after the polymerization process to 35 Å as evidenced from X-ray diffraction (XRD). The d-spacing of the PAn/H+-MMT nanocomposite was found to become wider about 23.79 Å than that of the pure Na+-MMT, and successful intercalation or exfoliation of PAnH+ into Na+-MMT layers. The prepared PAn/MMT nanocomposites were characterized by thermal gravimetric analysis (TGA), scanning electron microscope (SEM), and transmission electron microscope (TEM). The electrical property measurements showed an enhancement in the conductivity values of the prepared nanocomposites especially on using AnHCl monomer to be in the order of 10−1 S/cm.