Projet Scientifique
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This program focuses on the development, characterization and study of thin films of composite materials made of a mixture of polymers and crystals PDLC type liquid (Polymer Dispersed Liquid Crystals). The texture of these films is generally in the form of a polymer matrix in which are dispersed nematic liquid crystal droplets. By a suitable choice of the constituents of the mixture, one can obtain a transparent system when the film is subjected to a sufficient electric field and opaque in the absence of a field. These materials are interesting for their many applications including electroactive glazing and display devices, which highlight the centrality of their electro-optical properties. Interest in these systems is also motivated by the variety and importance of the fundamental questions they raise. Thus, the program of applied and fundamental aspects and is organized around several themes.
The first concerns the development of PDLC films using various techniques known by the way PIPS (Polymerization Induced Phase Separation). The second theme is to characterize the PDLC films using several different experimental techniques and in particular by infrared spectroscopy, differential scanning calorimetry, optical and electron microscopy, light scattering and small angle neutron.
Topics to be conducted in a priority order are:
- Properties of blends of polymers and molecules of molecular weight. Work on the theme of "development, characterization and study of mixed polymer systems - liquid crystal" will be pursued in particular nanocomposites and PDLC materials operating in reverse mode.
- Correlation of preparation parameters (chemical structure, implementation, etc.) and electro-optical properties.
- Relaxation of the transmission in the OFF state (TOFF after developing the film) and correlation with the phase separation kinetics in the main modes of development (TIPS - Thermally Induced Phase Separation, SIPS - Solvent Induced Phase Separation, PIPS to using the UV and EB radiation)
- Relaxations under electric field tON or tOFF
- Shear effects (mechanical, flow)
- Effects of aging (without and in the presence of electric field)
- Thermodynamic properties and study of miscibility
Bilan 2011-2015