CHLOROFORM-SOLUBLE POLY(O-METHOXYANILINE) FOR ULTRA-THIN FILM FABRICATION

One of the main difficulties in spreading Langmuir monolayers from conjugated (conducting) polymers is the lack of solubility of these polymers in common organic solvents. In this letter we report on a chemically synthesized polyaniline derivative, poly(o-methoxyaniline), which is soluble in chloroform and has been used to fabricate ultra-thin films in a Langmuir trough. The synthesized poly(o-methoxyaniline) comprised two parts, one of which has a low molecular weight (LW) (it is in fact an olygomer with a few monomers) whereas the other has a high molecular weight (HW) of approximately 28000 g mol-1. When separated, the LW fraction yields Y-type LB films by vertical dipping whereas films could only be deposited with the HW fraction if the horizontal lifting method was employed. When examined through the scanning electron microscope, the latter films presented less defects than the LB films obtained with the LW fraction. This is probably because pores which may have been present in the films obtained with the vertical dipping were not present in the more rigid monolayer of the HW fraction.