Particle Size Reduction of Polyaniline Assisted by Anionic Emulsifier of Sodium Dodecyl Sulphate (SDS) Through Emulsion Polymerization

Reduction of particle size of Polyaniline (PANI) evaluated after anionic surfactant assisted polymerization reaction was observed during synthesis. The use of Sodium Dodecyl Sulfate (SDS) during the reaction has reduced the particle size of PANI to the smallest 212 nm from original size 713 nm obtained from a synthesis of SDS free. The single compound of SDS has specific fingerprint at wavenumbers of 1247 and 1216 cm ^- 1 indicating an asymmetric stretching, vibration and a symmetric stretching vibration of SO ₂ molecule at 1080 cm ^- 1. After SDS assisted polymerization reaction completely, the fingerprint specifically appears in the range of 950 - 1000 cm ^- 1 wavenumber for SO ₂ molecule peaks. It indicates that there was SO ₂ molecule bonded into PANI molecule. It was obtained that the higher SO ₂ content in PANI of a high SDS concentration shows a wider of spectra and higher absorbency. In addition, there was no pH effect during the polymerization reaction under various SDS concentrations. It is concluded that the particles of PANI were reduced with the addition of SDS during polymerization reaction. The smallest average particle size obtained through the emulsion polymerization technique containing 0.67 % SDS was 212 nm.