Effects of monomer concentration on the structure and properties of polybenzidine micro rods

Polybenzidine was synthesized by interfacial polymerization under various monomer concentrations. Effects of monomer concentration on morphology, structure, and properties of polybenzidine were studied by techniques of Fourier Transform Infrared Spectroscopy, Ultraviolet Visible Absorption Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray Diffraction, and Cyclic Voltammetry. The results showed that the synthesized polybenzidine with monomer concentration less than 0.15 mol/L were micro rod-like and the surface of the micro rods was smooth and uniform, However, the micro rod-like polybenzidine cannot be obtained under high monomer concentration because of the explosive polymerization. The results of structural analysis indicated that the monomer concentration should not be very high to obtain the polybenzidine with the optimal degree of conjugation and order arrangement of molecular chain. The polybenzidine synthesized in different monomer concentrations showed different electrochemical activities and the sample with the best electrochemical activity was obtained at monomer concentration of 0.02 mol/L.