Electrical and barrier properties of modified polyaniline coating films and its effects on the corrosion protection of mild steel / Amirah Amalina Ahmad Tarmizi

摘要

The study investigated the coating properties of polyaniline (PANI),udpolyaniline with nano silica (PANI nSi) and polyaniline with 3-amino silaneudmodified nano silica (PANI 3-APS modified nano silica). Investigationudwere carried out on the effects of nano silica and amino-silane modifiedudnano silica fillers on the structure, morphology and its influence on theudelectrical and ionic barrier properties of polyaniline. Fourier TransformudInfrared (FTIR) showed the successful formation of PANI, PANI nSi andudPANI 3-APS modified nano silica. Correlation between concentrationudof acid and fillers weight ratio with conductivity were studied. Theudelectrical conductivity of all samples was determined using the bulkudresistance value obtained from the Nyquist plot in the frequency rangeudof 0.1 Hz to 100 MHz. PANI prepared in 0.1 M oxalic acid shows theudhighest room temperature electrical conductivity value of, 2.52 x 10-6udS cm-1. The highest electrical conductivity of PANI nSi was 2.4 x10-4 Sudcm-1 for PANI containing 20%w/w nano silica fillers. For PANI 3-APSudmodified nano silica, PANI added with 20%w/w of 3-APS modified nanoudsilica fillers exhibit the highest conductivity values which were 4.0 x10-6udS cm-1. PANI, PANI nSi and PANI 3-APS modified nano silica with theudoptimum condition was selected for further characterization. The studyudalso calculated the conductivity of all selected samples in wet condition.udThe transference numbers determined the conductivity behaviour of alludchosen samples in dry and wet conditions. The transference numbersudwere calculated using Wagner’s polarization method...