Ariadna B. Nowicka

Brillouin study of photopolymerization process of two-monomer systems

The results of Brillouin scattering investigations of two-component system: 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane/polyethylene glycol methacrylate (bis-GMA/PEGMM) containing 0, 30, 50, 70, 85 and 100 mol% of PEGMM are presented. For the first time the Brillouin spectroscopy was used to monitor the progress of the polymerization process. The polymerization was initiated by ultraviolet radiation (λ=365 nm), at temperature 20°C and 40°C. Some of the physical parameters characteristic for this system such as velocity V, adiabatic compressibility β(ad) and attenuation coefficient α of the acoustic waves have been estimated from Brillouin spectra as a functions of the polymerization time. The obtained results have been discussed in terms of changes of the elastic properties of the two-component system occurring during polymerization process and their dependence on bis-GMA/PEGMM system composition.

Morphology and molecular arrangement of perylene-3,4,9,10-(n-pentylester) in thin layers obtained by zone-casting

Liquid-crystalline perylene-3,4,9,10-tetra-(n-pentylester) zone-casted on hydrophilic glass substrates forms characteristic belt-like structures which are observed under optical microscope and atomic force microscope. Polarised Raman scattering spectra reveal the presence of anisotropic alignment of the molecules inside the obtained structures. Moreover, the absorption and fluorescence spectra confirm molecular aggregation in the belt-like structures. The research shows, that the belt-like structures are created by columns of molecules with the edge-on alignment on the glass substrate. Such organisation of the molecules is confirmed by spectroscopic methods. These structures can be interesting from the point of view of organic electronics.

Characterization of Carbon Nanomaterials by Raman Spectroscopy

Abstract This chapter describes the characterization of carbon nanomaterials by Raman spectroscopy. It emphasizes the capabilities of Raman microscopy for precise and noninvasive study of carbon nanostructures and its usefulness as a diagnostic tool for the identification and characterization of different types of carbon structures. The chapter is accompanied by information on the study of nano carbon structures such as graphene, carbon nanotubes, and micro and nano diamond structures. The chapter contains the most important information related to interpretation of typical Raman spectra of carbon nanomaterials, which is correlated with describing of structure, structural defects, quality of carbon structures, and mechanical properties, etc. Additionally shown application of Raman mapping techniques for surface characterization of carbon nanomaterials.