COMPOSITE LANGMUIR MONOLAYERS AND LANGMUIR-BLODGETT-FILMS FROM 16-MERPOLYANILINE

The formation of Langmuir monolayers and Langmuir-Blodgett films is re ported for the first time for a polyaniline oligomer, 16-mer, that was mixed with cadmium stearate. The processibility of this oligomeric ma terial was greatly improved as compared to the parent polyaniline, whi ch allowed one to use common solvents like chloroform as the spreading solvent. Analogously to composite polyaniline monolayers, the stabili ty and the transferability are found to depend on the 16-mer content i n the composite film, with poor stability and low transfer ratios abov e 60% of 16-mer. Deposited Langmuir-Blodgett films were found to be un doped (or only weakly doped) since they were obtained from monolayers spread onto aqueous subphases (pH = 6.0). Uniform Langmuir-Blodgett (L B) deposition was confirmed by optical microscopy and UV-vis spectra w hose intensity increased linearly with the number of layers deposited and also with the 16-mer content. Fourier transform infrared (FTIR) re sults revealed that cadmium stearate was transferred together with the 16-mer. Upon doping in HCl vapor, the electrical conductivity of the deposited LB films was seen to increase by 1 order of magnitude.