Self-organized properties of conductive Langmuir-Blodgett films

Langmuir-Blodgett films were fabricated from mixed monolayers containing st earic acid (SA) and various Head-to-tail poly(3-alkylthiophene)s (HT-PATs:a lkyl = hexyl (HT-PHT), decyl (HT-PDT), octadecyl (HT-PODT)). The HT-PATs co uld form stable monolayers on the air-water interface with stearic acid, an d could be deposited onto solid substrates as Y-type films by vertical dipp ing method. The structure of HT-PATs/SA LB films were investigated by trans mission and reflection-absorption FT-IR measurements. By comparison of tran smission and reflection FT-IR spectra, the tilt angles of alkyl side-chains of HT-PATs could be estimated. These results shows that self-organized pro perties and molecular orientation of HT-PATs were affected by the length of alkyl-side chains. HT-PDT was found to form more planar conformation becau se of the optimized length of alkyl-side chains.