Lateral spacings of the molecules in the Langmuir-Blodgett (LB) films were
controlled by introducing fullerene (C-60) molecules as the spacers. The sp
atially controlled LB films were deposited on the electrode of a quartz cry
stal microbalance (QCM) and the adsorption characteristics of the gas molec
ules were studied. The permeability of the gas molecules into the film was
higher when the molecular weight was lower or when the molecular size was s
maller. This molecular sifter function was caused by the adsorption of the
gas molecules not mainly to the spacer molecules but to the lipid molecules
. In order to prevent the structural change caused by the desiccation of th
e films, polymer backbones were added to the membrane. The spatially contro
lled LB films with polymer backbone were found to be a novel smell sensor w
ith a molecular sifter function and high durability. (C) 2000 Elsevier Scie
nce S.A. All rights reserved.