MOLECULAR SIFTER USING SPACE CONTROLLED LANGMUIR-BLODGETT-FILMS BY FULLERENE MOLECULES

We have found that the intermolecular spacing of an arachidic acid (C- 20) Langmuir-Blodgett (LB) film can be controlled by introducing a var iable amount of spacer molecules such as fullerene (C-60) into the fil m. Using this characteristic, several kinds of mixed LB films, compose d of C-20 and C-60, were prepared and the adsorption characteristics o f gas molecules, namely phytoncid (e.g. limonene, alpha-pinene), to th ese films were studied using a quartz crystal microbalance. The depend ence of the amount of the gas adsorbed on the number of layers reveal that the permeability of the gas molecules into the LB films remarkabl y increases with an increase of the intermolecular spacing of LB films . Gas molecules with different sizes or structures were sifted by usin g C-60 containing LB films. This characteristic of the LB films contai ning C-60 can be applied to a novel gas sensor with a molecular sifter function. (C) 1998 Elsevier Science S.A. All rights reserved.