čas: 16.10.2021 20:19:27
Obnovit | RAW
Department of Analytical Chemistry
List of available PhD theses
Development of Lanthanide Luminescent Complexes for Raman Spectroscopy and Imaging
Lanthanide luminescent complexes seem to be very suitable for imaging of living cells by the Raman microscopy. For example, they are more stable and spectra are more specific than for organic dyes. We will further improve their functionality so they will bind to specific biomolecules or cellular structures. Spectroscopic properties, such as fluorescent quantum yield, will be optimized as well. The work will include organic synthesis, characterization of the spectroscopic response, e.g., upon interaction with proteins and nucleic acids, and polarization measurements with left- and right-circularly polarized light.
Development of computer interpretation of nuclear magnetic resonance spectra for molecular structure elucidation.
Determination of molecular structure by means of computer programs, especially from NMR spectra, nowadays surpasses man not only in speed but also in accuracy. However, the interpretation of experimental spectra remains an unresolved part of molecular structure determination. The aim of this work is to process 1D and 2D NMR spectra using own algorithms that enable automated determination of molecular structure of studied compounds.
Development of high pressure Raman and Raman optical activity spetroscopy
Vibrational spectra at high pressures, such as of biologically relevant molecules, provides insight into molecular structure and interactions. We will measure Raman spectra of model systems in the diamond pressure cell and interpret the spectra based on molecular dynamics simulations. We will also try to further develop the technique so that new information can be obtained using differential scattering of left and right circularly polarized light (Raman optical activity).
Green, greener, greenest: thermodynamic properties of aqueous solutions of bio-based ionic liquids
The aim of this thesis is to obtain a better understanding of the structure-property relationships in aqueous mixtures of choline, phosphonium and ammonium-based ionic liquids (ILs) with bio-based anions (e.g. malonates or lactates). For this purpose, the proposed ILs will be synthetized in collaboration with the Université Reims-Ardennes where their application potential as solvents for lignin will be studied. Pure ILs and their aqueous mixtures will then be characterized in terms of their thermophysical and thermodynamic properties. Density as a function of temperature and pressure will be measured using oscillation tube densitometry, heat capacity as a function of temperature, phase and glass transitions will be measured by means of differential scanning calorimetry, and vapour pressure above the aqueous mixtures of the studied ILs will be determined ebuliometrically. The experimental data will then be analyzed by means of advanced methods of data analysis based on mathematical gnostics and will be used as input for Kirwood-Buff theory modelling. Last but not least, the macroscopic data will be interpreted in the light of suitable spectroscopic methods (FTIR, Raman, NMR spectroscopy).
Hygroscopicity of aerosol particles
Hygroscopicity of aerosol particles is their ability to bind air humidity. This changes their shape, size and phase behavior. Hygroscopicity affects the ability of particles to become cloud condensation nuclei, their optical properties, global climate change, and human health. The aim of the project is to study hygroscopicity of aerosol particles in the laboratory and in the atmosphere. In the laboratory, aerosol particles composed of substances commonly found in atmospheric aerosols will be generated and their hygroscopicity studied using HTDMA spectrometer. At the National Atmospheric Observatory Kosetice, atmospheric aerosol will be sampled using spectrometers HTDMA, SMPS, APS and AMS. Moreover, samples on filters and impactors will be analyzed in the laboratory. Experimental results will be compared with model predictions.
Laser and heat-induced redox processes for deposition of novel structures for solar-light photocatalysis
There is great ongoing interest in semiconductors including TiO2-based materials due to their potential in solar energy-to-electric conversion (solar cells) and solar energy-to-chemical energy conversion (water splitting and photo-catalyzed degradation of pollutants in atmosphere and water). Much recent attention to improve these materials for efficient solar-light catalysis is documented in the literature. In this project we propose a novel approach to these materials based on redox paths between metal oxides, which are induced by laser excitation and conventional heat treatment. Highly non-equilibrium deposition conditions due to laser excitation are expected to affect the electronic structure and reactivity of potential reactants to form products not observed under ambient conditions.
Preparation of nanostructured materials for C2-C3 hydrocarbon generation from CO2 in electrochemistry
Reduction of waste gaseous products in industry anticipates a capture or other form of CO2 decrease. Simultaneously, a burst production of electrical energy from wind farms and/or photovoltaics parks enables an (electrochemical) generation of simple hydrocarbons from a waste CO2. Therefore, it is advisable to search for novel electrode materials for effective electrochemical reactions. The materials will be based on selected metal silicides and germanides prepared in nanostructured form. The doctoral student will synthetize the materials using laser chemistry and CVD and study by means of analytical techniques available in laboratory.
Preparation of solid surfaces with a molecular receptor covalently anchored, and studies of their usability in sensors construction.
The aim of this work is to modify the chemical structure of molecular receptors functional in solution so that they can be covalently attached to a solid surface or prepare a polymer. Study the functionality and usability of such materials for sensor construction.
Spectroscopic analysis of biologically active compounds in the solid state
Drugs, food components or other biologically active substances often need to be analyzed in the solid state. We will concentrate on the detection of model systems using infrared and Raman spectroscopic methods. These methods are relatively easy to use, but may have sensitivity limits, require special sample preparations and the interpretation of the spectra can be difficult. In the project, we will try to complete unpolarized measurements by vibrational optical activity and develop computational and simulation tools for prediction and interpretation of the spectra.
Structure of carbohydrates investigated by NMR spectroscopy and molecular modeling
Carbohydrates are the most abundant biomolecules with enormous structural diversity. They are present in the Nature in the form of mono-, di-, oligo- or polysaccharides but also as a part of glycoconjugates such as glycoproteins, peptidoglycans or glycolipids. Consequently, this structural variety makes carbohydrates the least exploited among biomolecules. In addition to the structural diversity, originating from multi-linkage and branching of monosaccharides, carbohydrates are usually flexible molecules that can exist in various conformations. All this makes structural studies of carbohydrates difficult and challenging.
NMR spectroscopy is, among other experimental techniques, the most exploited method in determination of carbohydrate structure. The advantage of NMR is the possibility to study molecules of interest in both solution and solid state and at the same time correlate multiple parameters (chemical shift, coupling constants, NOE, relaxation times) with the structure. On the other hand, NMR spectra of carbohydrates are complex due to significant signal overlap and averaging of NMR parameters in solution experiments. Many NMR parameters respond sensitively to changes in structure, which is however not directly deducible from NMR spectra. Therefore, a combination of experimental NMR with molecular modeling techniques is frequently used in carbohydrate structure determination.
The aim of the PhD project is studying of carbohydrate structures by NMR spectroscopy and explore various NMR techniques in combination with molecular modelling that can be used in order to fulfil this task. Particular emphasis will be given to the sensitivity of NMR parameters to conformational changes and to the influence of the environment on carbohydrate structure. The studied compounds will be synthesized in a collaborating laboratory of Dr. Kamil Parkan at UCT Prague.
Study of conformation and solvation envelops of bioactive compounds in solution via NMR
The work deals with conformations and solvation envelopes of biologically important substances (drugs) using NMR. The aim is to develop experimental methods to obtain detailed information about the conformers of substances in solution, and their interaction with solvent molecules or solutes. The aim is to correlate the information obtained with the structure of substances in the crystals, physicochemical properties and biological activity.
Study on transformations of organic aerosols
Secondary organic aerosols (SOA) as important components of atmospheric aerosols influence Earth’s climate, human health and life expectancy. They are produced by atmospheric photooxidations of anthropogenic and biogenic volatile organic compounds (BVOCs) via gas-to-particle conversion. Terpenes and isoprenes belong to the most abundant chemical species detected in BVOC emissions. They can be oxidized to form semi- and low-volatile carbonyls, acids, and other products, transitioning between gas and particulate phase. To correctly describe these transformations by mathematical models, knowledge of thermodynamic and transport properties of these compounds is needed. The doctoral student will study these phenomena using advanced aerosol instrumentation including on-line chemical and physical characterization of particles by mass spectrometry.
Theory and interpretation of molecular optical activity spectra
Spectroscopy using molecular optical activity is indispensible in analytical chemistry of chiral compounds. Interpretation of the spectra is often based on their simulations by methods of computational chemistry. However, for many cases, special theory and procedures need to be used which are not available in common software. We will concentrate on resonance molecular phenomena and develop protocols suitable for interpretation of enhanced vibrational circular dichroism and resonance Raman optical activity. The theoretical procedures will be tested with experimental data.