Calculation of the surface potential across Langmuir-Blodgett films with polar molecules

The surface potentials across multilayer films with polar molecules were calculated assuming that the constituent molecules are rod-like and orientationally distributed. In the calculation, the internal electric field was taken into consideration. The effect of the excess charges displaced from the base metal electrodes was also taken into consideration. It was found that the excess charges displaced om base metal electrodes contribute to the change in orientation of polar molecules which results in a change in the voltage across the monolayers. The experimental results for precursor films of polyimide with polar groups (-OCF3, -OCH3) are discussed based on the analysis developed here.