Properties Of Polymer Thin Films

The PLASMA POLYMERIZED 1-BENZYL-2-METHYLIMIDAZOLE (PPBMI) thin films were prepared by plasma polymerization technique using a capacitively couple reactor. The structural, optical and ac electrical properties of PPBMI thin films were studied. The SEM investigation reveals that the PPBMI thin film deposited on to glass substrates are smooth, uniform and pinhole free. FTIR investigation shows that the chemical structure of PPBMI thin films is different from that of BMI monomer. UV-Vis absorption spectra show a red shift for all PPBMI thin films as compared to the monomer. The ac conductivity of PPBMI thin films increases linearly with frequency. The ac conductivity increases slowly at low temperature. The small values of activation energy indicate hopping type of conduction mechanism in films. The dielectric constant of PPBMI thin films increase with increasing temperature. It is seen that value of dielectric loss increases with increasing frequency and temperature. It can be inferred that the optical and electrical property of PPBMI thin films is not significantly dependent on thickness. This signifies that PPBMI thin films are uniform through the bulk.