Search

A quartz-crystal microbalance (QCM) was employed as a substrate for a horizontal lifting method of various LB films, in which the QCM plate was touched to monolayers on a subphase and lifted horizontally. The transferred mass of monolayers on the QCM could be measured directly at a nanogram level from a frequency decrease of the QCM plate: two monolayers were deposited each cycle (Y-type, transfer ratio 2). The QCM method gave more precise transfer information than the conventional method using the moving area of the barrier on the trough. It was found by the QCM method that Y-type horizontal lifting methods could be widely applied for most monolayers to form well-layered LB films, compared with the conventional vertical dipping method.

We report the first successful transfer of layers of a poly(dialkoxythiophene), poly(3,4-dibutoxythiophene), by the Langmuir-Blodgett technique. A stable monolayer was prepared at 11°C on a water surface and layers were transferred onto glass substrates by vertical dipping with a transfer ratio of 1.00±0.05. The UV-visible absorption spectrum indicated regular stacking of layers. The effects of polymer structure on processing by the Langmuir-Blodgett technique and on optical properties are discussed.

We describe results for the dynamic contact angle and transfer ratio for the deposition of docosanoic acid monolayers on to mica from CdCl 2 subphases as a function of pH. The deposition changes from Z to Y type at approximately the pH corresponding to half ionisation. Deposition on OUT strokes occurs for dynamic contact angles 90° and is consistent with a hypothesis of Bikerman.

The metal-base triode sandwich was used to measure the current transfer ratio in a Schottky-barrier triode structure. The transfer ratio is discussed considering two distinct current types: that through the base metal and that through pinholes.