Preparation of Langmuir-Blodget Films of Phthalocyanines and Investigation by Atomic Force Microscope

Abstract

The Langmiure-Blodget monolayer films of five solvent-soluable phthalocyanines, bis-(benzyloxy) phthalocyaninatosilicon. bis-(p-chlorophenoxy) phthalocyaninatosilicon, bis-(p-chlorophnoxy) (tetra-4-nitrophthalocyaninato)silicon, bis-(p-bromophenoxy) naphthalocyaninatosilicon, propoxy-(tetra-4-nathalenoxypthalocyaninato)aluminium have been prepared by using Langmiure-Blodget techniques and their surface properties have been studied. When phthalocyanines dyes with no peripheral substituents were spread on a subphase of water to form LB film, the molecular state of LB film changed form G(gaseous) film into L 2 (liquid condensed) film and finally into multi-layer film (crinkled). The π-A isotherms of phthalocyanine LB film depended deeply on the molecular structure, especially on the phthalocyanine ring and substituted groups. The morphology of the LB film was investigated by AFM (atomic force microscope) analysis. It was shown that domains of dye molecules formed on the LB film. Five phthalocyanine dyes gave different morphology domains which the forms, sizes, arrangement, orientation and distribution were related to molecular structure and dipping condition.