ATOMIC-FORCE MICROSCOPY CHARACTERIZATION OF POLY(AMINO ACID) LANGMUIR-BLODGETT-FILMS

Atomic force microscopy (AFM) has allowed us to obtain molecular resol ved images of Langmuir-Blodgett (LB) monolayers of docosanoic acid (DA ) deposited on a glass substrate, monolayers of poly-(beta-benzyl-L-as partate) (PBA) and poly(L-alanine) (PAL) deposited on a mica substrate , and bilayers of PBA and PAL on graphite. Evidence of sample damage b y the AFM tip has been shown. Studies in the periodicity and conformat ion of the molecules on each type of substrate (hydrophobic or hydroph ilic) have thus become possible leading to the measurement of the inte rchain distance for PBA and PAL.