Abstract
Composites with a polymer matrix based on single crystals have great potential in the field of optical communication systems where active micro to nanocrystals dispersed in an optically transparent matrix. The subject of this doctoral thesis includes research in the field of optoelectronic functional composite materials with a polymer matrix for use in electronic technologies, as well as in the field of communications and navigation techniques and possibilities for developing integrated optics and photonics. Polymer optoelectronic composite materials with controlled optical properties were synthesized. One way is use of the inorganic particle size smaller than the wavelength of electromagnetic radiation to avoid scattering. Another way is the installation of materials with similar values of the refractive index. Within this selection of these materials fell on the poly (methyl methacrylate) with an index of refraction n600 = 1.49. Research was organizedfor studying synthesis and characterization of polymer matrix composites incorporating CdSe quantum dots. In such an organized way research can be traced and influence the organization and size of crystals in the optical and mechanical properties of the resulting composite. Quantum dots (QD) are monocrystalline semiconductor nanostructures, whose head electric charge spatially confined in all three dimensions. The material from which the QD made defines their characteristic energy. However, the exact value of the energy gap are determined by the size of the point. The consequence of this is the fact that quantum dots made of the same material but different sizes emit radiation of different wavelengths. The present work was carried out testing of the conditions for obtaining a QD doped poly (methyl methacrylate) thin film by method of casting from solution. The thermal properties of composites were investigated by the DSC method. Optical properties were investigated by analyzing the emission spectrum of picosecond measurement system for measuring the lifetimes of luminescence. Mechanical properties were tested using the method of nanoindentation. The results of DSC revealed that for composite QD doped PMMA film have somewhat lower Tg in comparison with pure PMMA. The reason for this decrease in Tg is QD interaction with the main chain of the polymer PMMA. Nanoindentation test results show that the addition QD increases reduced modulus of elasticity and hardness. I kind of behavior of the composite film points to the interaction of nanoparticles QD and the base polymer chain PMMA. These particles prevent the initiation of a polymer chain and thus improve the mechanical properties of the composite. Fluorescence spectrum of the film showed that QD retain their optical properties and respond well in the PMMA matrix to excite.