Slow Structural Rearrangement of a Side-Chain Phthalocyanine Methacrylate Polymer at the Air-Water Interface

A polymethacrylate with dodecoxy-substituted phthalocyanine units in the side chains has been used to form Langmuir-Blodgett monolayers at the air-water interface. The monolayers are highly crystalline. They expand slowly even when a constant surface pressure is applied. The structural change coupled with this process has been studied by electron microscopy, electron diffraction, and ellipsometry. It is proposed that the expansion is the result of a change in conformation of the peripheral alkoxy chains on the phthalocyanine rings. The polymer can be deposited on various substrates with Y-type transfer if it is mixed with arachidic acid. The resulting multilayers have been characterized by UV/vis and FT-IR spectroscopies and ellipsometry. No flow-induced orientation was observed during the transfer process.