Langmuir balance device

The behaviour of polymeric polypeptides at the air/water interface was studied. Relative hydrophobicity was quantified using a Langmuir balance device designed and constructed in our laboratory (FR) according to Verger and de Haas. " ... 

The dependence of the surface tension of a Langmuir layer containing a given amount of surfactant, as a function of its area, reveals many of the properties of the surfactant. (At constant temperature, such measurements are analogous to determining the P-V isotherm of a gas.) One device for making such measurements is the Langmuir balance, the essential principles of which are shown in Fig. 10. 

Devise a method to accurately use two Wilhelmy plates (see Fig. 6) to measure the surface tension of a Langmuir film. Do not forget about the gravitational and buoyancy forces. Such a device is called a Wilhelmy balance. 

High-resolution circuitry and active devices employing Langmuir-Blodgett film techniques or polymer-based transistors are being considered for the sophisticated electronics required in future vehicles. Temperature or energy balance in the vehicle could be controlled through conductive polymers or semiconductor deposits on electrochromic windows. Electroluminescent liquid crystals and fluorescent and electrochromic materials used for visual displays show promise for future development. 

There are examples in the literature where the balance between holes and electrons is reached by inserting a hole blocking material between the ITO and the active polymers. For example, a simple polymethylmethacrylate (PMMA) monolayer prepared by means of the Langmuir Blodgett technique was reported to give a four-fold efficiency increase if introduced between the FLO and the active layer [113]. Greenham, Niiesch and Yang [114-116] followed similar approaches to control the performance of a MEH-PPV based device and a polyparaphenylene-based device respectively. 

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