A trough with radial compression for studies of monolayers and fabrication of Langmuir-Blodgett films

Abstract

A new type of Langmuir trough with radial compression is reported for studies of monolayer properties and fabrication of Langmuir-Blodgett (LB) films. The trough included twenty curved diaphragms, which form a circular shape on water and compress monolayers. Typical monolayers of arachidic acid, DL-α-phosphatidylcholine dipalmitoyl, cellulose tridecanoate, and poly (butyl methacrylate) showed reproducible surface pressure-area isotherms with radial compression. Flow profiles were studied of monolayers on cellulose tridecanoate and poly(butyl methacrylate) and suggested that the monolayers are radially compressed with no particular film disturbance. A Wilhelmy glass plate preserved no deflection in the subphase surface from low to high surface pressures during the film compression and decompression; no pressure excess causing the deflection, which is frequently observed in the case of the film compression with a sliding barrier, was found on both sides of the Wilhelmy plate. Application of the radial compression enabled to do a symmetrical deposition for the fabrication of LB films.