Observation and manipulation of polymers by scanning tunnelling and atomic force microscopy

Abstract

SUMMARY The properties of monolayer films of organic materials are important for a variety of technologies. We have employed STM and AFM to study Langmuir‐Blodgett films of a variety of polymers on substrates of graphite, MoS 2 , and Au(111) on mica. The polymers were poly(octadecyl acrylate) (PODA), atactic and syndiotactic poly(methyl methacrylate) (PMMA) and poly(2‐methyl‐1‐pentene sulphone) (PMPS). One striking feature was the degree of order observed; a second was the morphological difference between films of submonolayer thickness (long, thin fibrils) and those of at least monolayer thickness (lumpy structures arranged in domains). By pulsing the STM bias voltage to values in excess of 4V, we were able to bring about local modification of the polymer morphology.