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

The study investigated the coating properties of polyaniline (PANI),
polyaniline with nano silica (PANI nSi) and polyaniline with 3-amino silane
modified nano silica (PANI 3-APS modified nano silica). Investigation
were carried out on the effects of nano silica and amino-silane modified
nano silica fillers on the structure, morphology and its influence on the
electrical and ionic barrier properties of polyaniline. Fourier Transform
Infrared (FTIR) showed the successful formation of PANI, PANI nSi and
PANI 3-APS modified nano silica. Correlation between concentration
of acid and fillers weight ratio with conductivity were studied. The
electrical conductivity of all samples was determined using the bulk
resistance value obtained from the Nyquist plot in the frequency range
of 0.1 Hz to 100 MHz. PANI prepared in 0.1 M oxalic acid shows the
highest room temperature electrical conductivity value of, 2.52 x 10-6
S cm-1. The highest electrical conductivity of PANI nSi was 2.4 x10-4 S
cm-1 for PANI containing 20%w/w nano silica fillers. For PANI 3-APS
modified nano silica, PANI added with 20%w/w of 3-APS modified nano
silica fillers exhibit the highest conductivity values which were 4.0 x10-6
S cm-1. PANI, PANI nSi and PANI 3-APS modified nano silica with the
optimum condition was selected for further characterization. The study
also calculated the conductivity of all selected samples in wet condition.
The transference numbers determined the conductivity behaviour of all
chosen samples in dry and wet conditions. The transference numbers
were calculated using Wagner’s polarization method...