Vibrational Spectroscopy
Vibrational spectroscopy provides information on macromolecules with respect to their composition, structure, conformations, and intra- and intermolecular interactions. Vibrations of molecules consist of periodic changes of the length of bonds between atoms and of the bond angles. Vibrational modes of molecules exhibit discrete values of energy. Due to interaction of electromagnetic radiation with the studied substances we obtain vibrational spectra providing information on the molecular structure. While infrared spectroscopy employs absorption of infrared radiation, Raman spectroscopy is based on inelastic scattering of monochromatic light, usually from a laser emitting in the visible or near-infrared region. Both methods are widely used in polymer science.
The activity of the Department is focused on structure analysis of macromolecules by advanced methods of Raman and Fourier transform infrared (FTIR) spectroscopy, including resonance (RRS) and surface enhanced Raman spectroscopy (SERS), spectroelectrochemistry (SEC), microspectroscopy, temperature and time series, in combination with theoretical model calculations. Modern instrumental equipment provides the possibility of analyzing a wide range of samples, from low-molecular-weight compounds and polymers in solution to solid materials in many forms (films, gels, layers, powders, composites, etc.). The expertise of the research team in structure analysis underlies its participation in many projects together with other research groups at the IMC and and also international cooperation. The team is composed of three senior scientists, three young researchers, and a skilled technician.
Current Research Topics
Main fields of current research include self-organized systems based on cellulose and surfactant block copolymers, conducting polymers and related materials, electrolytes for lithium ion batteries, coatings and polymer blends. The Department also participates in dealing with many other topics studied at the Institute. Knowledge of the structure at a molecular level, resulting from vibrational spectroscopy, is correlated with macroscopic properties of the materials, which enables their deep understanding and prediction.
Conducting polymer nanostructures display high application potential. Their structure and principles behind their formation are investigated by combinations of spectroscopic methods. For example, Raman microspectroscopy with several excitation wavelengths of varying penetration depth elucidated the internal structure of polypyrrole — methyl orange nanotubes. Not only conducting polymers themselves, but also related oligomers are important for understanding the material properties. Aniline and pyrrole oligomer formation in neutral and acidic medium and their electroactivity were elucidated using SERS SEC and in-situ attenuated total reflection (ATR) FTIR.
The interaction of conducting polymers with dopant species were studied by infrared and Raman spectroscopy to better understand their molecular structure. A model was proposed for the formation of new non-covalent bonds with a phosphite tautomer replacing the bonding in the polyaniline base. The conducting polymers are promising contrast agents for the photoacoustic imagining in medicine. The nanoparticles structure and their near infrared photoacoustic response was evaluated by the photoacoustic spectroscopy in near- and mid-infrared range.
The investigation of self-organized systems is focused on the behavior of cellulose and mixtures of cellulose with synthetic polymers in ionic liquids, ionic liquid/water systems as well as more conventional solvents. The study and characterization of emerging nanostructures of cellulose and block copolymers using Raman and FTIR spectroscopy together with quantum chemical model calculations allows a detailed description of specific intermolecular interactions relevant for the design of new self-organized materials (blends or nanocomposites).
Main fields of current research
- aggregation behavior of thermoresponsive block co-polymers
- cooperative interactions, mobility and interactions in polymer blends
- hydrogen bonding in cellulose and model systems
- conducting polymers, in particular polyaniline and polypyrrole
- nanocomposites based on conducting polymers
- infrared and Raman spectroelectrochemistry of conducting polymers
- study of thin layers by surface enhanced Raman spectroscopy (SERS)
- intercalated clays and modified magnetic nanoparticles for medicinal purposes
- degradation of polyolefins for medicinal and construction purposes
- theoretical calculations: molecular modelling, quantum chemical methods
Cooperation
- Faculty of Physical Chemistry, University of Belgrade, Serbia (Prof. Gordana Ćirić-Marjanović)
- Institute of Polymers, Slovak Academy of Sciences, Bratislava, Slovakia (Dr. Mária Omastová)
- Leibniz Institute on Solid State and Materials Research, Dresden, Germany (Dr. Evgenia Dmitrieva)
- School of Science and Technology, Kwansei Gakuin University, Sanda, Japan (Prof. Yukihiro Ozaki)
- Department of Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden (Prof. Magnus Johnson)
- Department of Materials Science, University of Leoben (Dr. Lidija Rafalović)
- Erich Schmid Institute of Materials Science, Austrian Academy of Science (Prof. Jürgen Eckert)
- National Institute of Chemistry, Slovenia (Prof. Nejc Hodnik)
Funding support
We obtained funding for basic and applied research from national grant agency, the Czech Science Foundation, recently we were supported by the following funding:
- Czech Science Foundation: Vibrational spectroscopy and spectroelectrochemistry of the first products formed during conducting polymer preparation 18-01924Y (Z. Morávková)
- Czech Science Foundation: Role of non-covalent interactions in miscibility of cellulose with synthetic polymers in complex solvent systems (J. Dybal, 17-03810S)
- Czech Science Foundation: Study of the materials based on the conducting polymers by advanced spectroscopic methods (M. Trchová, 17-04109S)