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Molecular chemical physics and sensorics
Doctoral Programme,
Faculty of Chemical Engineering
--- Careers--- Programme Details
Ph.D. topics for study year 2024/25Ab initio modeling of charge-carrier mobility in polymorphic of organic semiconductors
AnnotationLarge structural and chemical variability of organic semiconductors raises the need for computational screening of the electronic structure of the bulk phase and related material properties, such as the band gap or the charge-carrier mobility. The latter property remains rather low for most existing organic semi-conductive materials when compared to the traditional inorganic crystalline platforms of the optoelectronic devices. Understanding relationships among the bulk structure, non-covalent interactions therein, electronic properties, conductivity, and the response of all such properties to temperature and pressure variation will greatly fasten the material research in the field of organic semiconductors. This thesis will employ the established electronic structure methods with periodic boundary conditions, as well as fragment-based ab initio methods to map the cohesion of bulk organic semiconductors with the charge-carrier mobility is both crystalline and amorphous structures of these materials. Ab initio calculations and the Marcus theory will be used as the starting point for a detailed investigation of the impact of local structure variations, due to chemical substitution, thermal motion, or polymorphism on the conductivity of target materials.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Ab initio polymorph stability ranking for molecular crystals of organic semiconductors
AnnotationOrganic semiconductors represent a broad material class offering interesting properties such as potential biocompatibility, large structural variability, mechanical flexibility, or transparency. These promising properties, however, cannot outweigh insufficient conductivity of the organic matter when compared to crystalline silicon, which impedes wider spread of alternatives to the traditional inorganic platforms for optoelectronic devices. This work will concern development and applicability testing of quantum-chemical methods for modelling polymorphism of molecular crystals similar to relevant organic semiconductive materials. Larger molecular size, high degree of conjugation and frequent heterocyclic nature of the target molecules represent the challenges that the computational chemistry has to face in order to provide accurate decription of molecular interactions in this field. Accurate quantum-chemical treatment of the non-covalent interactions, their relationship to the bulk structure, and the stability of individual polymorphs at various conditions will be targeted within this thesis. Finally, an interpretation of the impact of subtle variations of bulk structure on the charge-carrier mobility in organic semiconductors will be searched for.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Ab initio refinement of cocrystal screening methods for active pharmaceutical ingredients
AnnotationModern formulations of drugs often rely on cocrystalline forms the crystal lattice of which is built from multiple chemical species, mainly an active pharmaceutical ingredient and another biocompatible compound being called a coformer in this context. These cocrystalline drug forms often exhibit higher solubility, stability or other beneficial properties when compared to crystals of pure active pharmaceutical ingredients. Since molecular materials tend to crystallize in single-component crystals rather than in cocrystals, the task of finding a suitable coformer for a given active pharmaceutical ingredient may be very tedious and labor demaning. To circumvent the costly experimental trial-and-error attempts, in silico methods can help to preselect a list of possible coformers offering a high probability of forming the cocrystal. Currently available methods focus on screening the electrostatic potential around the assessed molecules and empiric pairing of its maxima and minima for the individual molecules, which enables coformer screening with a fair accuracy for predominantly hydrogen-bonded molecules. This thesis will aim at incorporation of ab initio calculations of molecular interactions that will bring further improvements also for cocrystal screening of larger molecules with prevailing dispersion components of their interactions. Also the impacts of stechiometry variations and of the spatial packing of the molecules in the cocrystal lattice will be newly considered, greatly enlarging the applicability range of the current cocrystal screening procedures.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Automated study of photochemical mechanisms
AnnotationThe thesis will focus on mechanisms of organic reactions in both the ground and excited states. Ab initio techniques and methods of ab initio molecular dynamics will be used. It is anticipated that new computational techniques will be developed, in attempt to automatize the search for key aspects of reaction mechanisms.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Detection of released gases as early warning of Li-batteries disfunction
AnnotationThe operation of lithium-ion batteries (LIB) always brings a certain risk of the so-called "thermal runaway of batteries". To specify it in more details the short-circuit inside the battery may cause local overheating which destroys internal insulation. Then the increasing electric current stimulates further increase of temperature, leading to release of explosive or toxic gases to the environment with the danger of fire or explosion. It was experimentally proved, however, that focusing on detection of small concentrations of released gaseous species, we can reliably identify early stages of battery destruction, which can be a basis of early-warning systems indicating LIB malfunction. The gaseous species which are released from LIB during thermal runaway, are mostly CO2, CO, H2 and CH4. The student will induce the conditions which take place during LIB malfunction and will be focused to development of sensors (preferably chemiresistors) that enable to detect the above mentioned gaseous markants.
Contact supervisor
Study place:
Department of Physics and Measurement, FCE, VŠCHT Praha
Statistical approach to excited state dynamics
AnnotationThe work will focus on modern approaches of data science for accelerating dynamical calculations in the excited states. The techniques will be applied for modeling static and time-resolved electronic spectra.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Photochemical processes in astrochemistry
AnnotationThe Thesis will focus on processes initiated by light in various astrochemically relevant molecules and system. In particular, the applicant will study ice particles and the role of high-energy radiation in astrochemistry. For more information, see http://photox.vscht.cz.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Transition metal complexes in chemical sensing
AnnotationTraditional materials for solid-state chemoresistive gas sensors are semiconductor materials like metalloids, semiconductor metal oxides or organic semiconductors. Transition metal complexes are a very promising class of materials, which are mostly overlooked. They offer, depending on the transition metal ion and the design of the ligands, the possibility of various features with the desired chemical and electronic structure. These compounds are therefore suitable candidates for multiple applications such as gas/chemical sensing. Within this project, new coordination complexes (using transition metals such as Ni, Cu and other potentially attractive metals) will be developed and synthesised (in collaboration with Karlsruhe Institute of Technology). The ligands will be designed appropriately and combined with the late first row transition metal ions to lead to the desired structural vacancies. In a second step, these complexes will be used for thin film processing in order to test them as active layer for gas detection. The preparation and analysis of the thin films is crucial to use them for selective and sensitive detection of harmful and toxic gas analytes. The attention will be aimed to chemoresistive and optical gas detection principles. Theoretical calculations (done in collaboration with the Max Planck Institute) will help to understand the sensing mechanism and provide a route to develop and improve the complex design in a systematic way.
Contact supervisor
Study place:
Department of Physics and Measurement, FCE, VŠCHT Praha
Modelling Charge Transfer Processes in Liquid Phase
AnnotationCharge transfer processes are fundamental to understanding chemical reactions. Traditional electrochemical techniques often struggle to fully characterize these processes. However, recent advancements in liquid phase photoemission spectroscopy offer promising avenues for integrating spectroscopy with electrochemistry. In this thesis, the applicant will employ innovative methods from quantum chemistry, statistical mechanics, and molecular modeling to elucidate the connection between these fields.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Modelling Extremely Concentrated Electrolytes
Annotation
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Molecular simulations of electrode-electrolyte interface
AnnotationThe thesis will focus on theoretical study of the interfaces between the electrode material and electrolytes. Extremely concentrated electrolytes will be studied as well, especially in the context of novel energy sources. The work will include techniques of quantum chemistry and statistical mechanics. For more information, see http://photox.vscht.cz/
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Multifunctional nano/micro-robot systems to fight bacteria infections
AnnotationThe rising resistance of bacteria to current antibiotics poses a significant global public health threat. Current antibiotic treatments often face challenges in delivering the medication effectively to the infection site, resulting in unintended off-target effects and the development and spread of drug resistance. Therefore, there is an urgent need for development of approaches that can effectively deliver antimicrobial payloads to the infection site. Micro/nano-robot-based drug delivery systems with anti-microbial properties have recently surfaced, capturing considerable interest as a potential therapeutic solution against bacterial resistance. Micro and nanorobots are miniaturized manipulatable devices designed for operation at the micrometer and nanometer scale. They exhibit the capability for autonomous or field-driven movement, actively transporting therapeutic payloads, executing precise micromanipulation, applying robust mechanical forces during locomotion, and responding to internal factors (such as pH, chemical gradients, etc.) or external stimuli (including a magnetic field, light, ultrasound, etc.). These attributes empower targeted antimicrobial delivery to infected sites and enhance penetration through bacterial biofilms. Despite the efforts made, this area of research is only in its infancy. For instance, to address complex infection conditions, it is essential to develop multifunctional antimicrobial micro/nanorobots. Moreover, biocompatibility and biodegradability/ retrievability of antimicrobial micro/nanorobots should be also considered during their design. This project will focus on the design, development and characterization of novel biodegradable multifunctional micro/nanorobots to fight bacteria resistances. The experimental development of the anti-microbial micro/nanorobots will be supported by computational design.
Contact supervisor
Study place:
Department of Mathematics, Informatics and Cybernetics, FCE, VŠCHT Praha
Multivariable chemical gas sensors
AnnotationThe topic of the thesis is the research and development of new types of chemical gas sensors – multivariable sensors based on photoluminescence combined with electrical conductivity measurement approaches or using quartz crystal microbalances (QCM). Multivariable sensing will improve sensor selectivity, detection limit, and reduce drift to increase their overall accuracy. Inorganic materials based on nanostructured metal oxides doped with lanthanides (e.g. SnO2, TiO2, ZnO and WO3) as well as organic materials, e.g. porphyrin derivatives, can be used as luminescent sensitive layers. Rare earth dopants have a high luminescent yield and a long lifetime, which facilitates optical detection, especially detection based on luminescence decay time. In the QCM scanning approach, it is advantageous to use layers of black metals (BM), e.g. Au, Al, Ag, Pd, Ti, ..., which exhibit an extremely large surface area due to the high porosity of BM, which is much larger than its geometric area. BM layers ensure a lower detection limit and increase the selectivity of the QCM sensor while maintaining a high quality factor value. QCM benefits from its robust nature, affordability, and affordable interface electronics. BM can also be used in chemiresistors, where there is a possibility of decorating their surface using the above-mentioned luminescent layers and other materials (e.g. 2D nanomaterials). Thin film structures will be prepared by PVD techniques (evaporation, magnetron sputtering, pulsed laser deposition). To modify the properties of the structures, the interaction with intense laser radiation will also be investigated. The use of AI technologies is beneficial for evaluating sensor response. The functional properties of the sensors will be optimized based on the characterization of thin films including optical, structural, electronic structural and sensor properties. The results will be important for the development of more efficient devices for chemical gas sensors. Devices based on the developed sensors could provide fast and reliable detection of trace amounts of chemicals and explosives, which is a high priority for security, defense, critical infrastructure protection, industrial process and environmental monitoring. The work will be carried out in cooperation with the Institute of Physics of the Czech Academy of Sciences, v.v.i., with the possibility of involvement in the project of excellent research of the OPJAK program "Sensors and detectors for the information society of the future", projects supported by the Czech Science Foundation and the Technology Agency of the Czech Republic and international cooperation.
Contact supervisor
Study place:
Department of Physics and Measurement, FCE, VŠCHT Praha
Protective shields for autonomous systems against electromagnetic interference
AnnotationThe rapid advent of autonomous systems such as robotic assistants, drones or self-driving vehicles has inevitably brought with it an increase in the use of positioning devices, such as microwave sensors, or advanced lidar, radar or radio technology. This also increases the likelihood of the occurrence of undesired interferences of this electromagnetic wave with the integrated circuits of the autonomous device, which may in turn lead to an increased probability of the occurrence of dangerous phenomena, including accidents and loss of life. The aim of this work is therefore to develop new materials for the attenuation of electromagnetic interference and to apply them as protective shields in the operating area of the electromagnetic spectrum of existing positioning systems. The work will focus on the search, synthesis and characterization of suitable electrical and magnetic materials and their nanostructured analogues and the subsequent design, manufacture and testing of new lightweight and flexible shields. Part of the work will also be modelling and evaluation of the shielding efficiency of protective shields in simulated and real conditions of operation of autonomous systems.
Contact supervisor
Study place:
Department of Mathematics, Informatics and Cybernetics, FCE, VŠCHT Praha
Proton Coupled Energy Transfer
AnnotationProcesses that involve the simultaneous transfer of electrons or energy along with atoms, typically hydrogen or protons, are widely recognized for their significant involvement in biophysical phenomena. This thesis will center on the emerging field of proton-coupled energy transfer (PCEnT) from a theoretical chemistry standpoint. The research will integrate quantum dynamics, molecular simulations, and modern quantum chemistry methodologies. Collaboration with experimentalists is envisioned.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Sensor arrays of tactile temperature and pressure sensors
AnnotationTactile temperature or pressure sensors are devices used in robotics to evaluate the robot's interaction with other objects. These include, for example, manipulating an object, measuring the slip of a gripped object, determining the coordinates of the position of the object or measuring the magnitude of the force acting on the object. The extreme case is complex tactile systems, the purpose of which is to simulate and replace human touch. The sensors used for these purposes must be sufficiently miniature, sensitive to small changes in pressure, must have favorable dynamic properties and time and operational stability of the parameters. Due to the expected high density of tactile sensors connected in simple applications, there must be the possibility of their operation in the form of sensor arrays and data processing using advanced mathematical and statistical algorithms. Last but not least, the cost of producing them must be reasonable so that they can be easily replaced in the event of wear. The aim of this work is therefore to develop new types of tactile temperature and pressure sensors based on modern nanomaterials, which can be used in experiments with the measurement of temporally and spatially distributed forces acting on the matrix of sensors. Part of the work will be the preparation, characterization and processing of thermoelectric and piezoresistive materials based on organic nanostructured semiconductors and carbon nanostructures. Testing of these substances will include, inter alia, structural, chemical and mechanical analysis and measurement of electrical properties in both direct and alternating electric fields. Selected materials will then be processed into sensitive sensors. Part of this work will also be the design of sensor arrays and their testing and signal processing using advanced algorithms.
Contact supervisor
Study place:
Department of Mathematics, Informatics and Cybernetics, FCE, VŠCHT Praha
Transport of charge carriers in nanostructured and nanocomposite materials
AnnotationThe topic of the thesis is theoretical and practical study of charge transfer mechanisms in nano-structured and nano-composite materials prepared in the form of thin films, coatings and aerogels. The aim of the thesis is to design models describing the charge transfer in real materials used for chemical sensors. The properties of the nanostructured samples will be measured in the Quantum Design - PPMS system, depending on the temperature and intensity of the magnetic field. The work involves (i) modeling and simulating the transport of charge carriers using the finite element method, (ii) designing and implementing software for managing, collecting and processing data obtained from PPMS system; (iii) seeking an analytical model describing the real (measured) properties of the samples depending on their nanostructure.
Contact supervisor
Study place:
Department of Physics and Measurement, FCE, VŠCHT Praha
Ultrafast reactions studied with X-ray spectroscopies
Annotation
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Toward first-principles prediction of phase behavior for amorphous molecular materials
AnnotationKnowledge of the phase behavior of substances is a key factor for the design of amorphous molecular materials, such as organic semiconductors or pharmaceutical formulations. Large structural and chemical variability of these materials require the application of computational screening methods that would enable fast and as-accurate-as-possible estimation of their bulk thermodynamic properties. Common molecular mechanics methods (e.g., grand-canonical Monte Carlo simulations) with classical force field models for predicting the phase behavior are notoriously challenging and give results that are far from acceptable numerical accuracy. Therefore, this thesis aims at developing a novel computational methodology based on a unique synergy of established first-principles electronic structure methods and efficient Monte Carlo simulations to map the thermodynamic properties (e.g., densities, enthalpies, and Gibbs energies) of different phases at a wide range of temperatures and pressures to construct global phase diagrams. Furthermore, this approach will enable a better understanding of the relationship between the molecular properties and interactions and the macroscopic phase transformations of bulk materials. At each stage, the developed methodology and its features will be compared with the available experimental data and results from existing computational approaches. Since it is expected that the methodology will exploit various different computational frameworks, the project will also include the creation of program tools for the required interfaces and processing of the simulated data in a form that would allow automation of the calculations, making the developed methodology available to a broader community.
Contact supervisor
Study place:
Department of Physical Chemistry, FCE, VŠCHT Praha
Utilisation of aerogels for gas sensors
AnnotationSignificant development of technology of nanomaterials in the last two decades has enabled the preparation of a wide range of materials for sensoric applications with unique structure and properties. Relatively simple supercritical drying technique, can be used to prepare active layers from the materials used for gas sensors in the form of aerogels. From the point of view of chemical sensors, such nanostructured materials show unique properties in many ways (high sensitivity and selectivity, large active surface). The aim of the work will be the design and implementation of sensors based on aerogels formed by inorganic oxides and their possible chemical (selective organic receptors, surface tension modifiers) and physical modification (laser annealing, incorporation of catalytically active nanoparticles). Impedance spectroscopy and UV-VIS-NIR spectrometry will be used to evaluate the sensor response.
Contact supervisor
Study place:
Department of Physics and Measurement, FCE, VŠCHT Praha
Development of modern electromagnetic radiation shields as passive protection of information against eavesdropping
AnnotationThe proliferation of modern electronics, integrated circuits, microprocessors and communication and computer technology in general brings with it a high risk of disclosing critical information about the infrastructure in which these elements are used. In the extreme case, there may be a leak or takeover of administrative privileges, which can be misused for digital vandalism, disclosure of important information or attacks on the infrastructure itself. One of the very effective and difficult to detect methods of these attacks is the remote eavesdropping on information that is emanated from electronic devices in the form of electric or magnetic fields. With the development of inexpensive radio technology and as a result of readily available libraries and signal processing algorithms, such an attack may no longer be the sole domain of rich, state-sponsored organizations, but may gradually be adopted by the mainstream hacking community and misused for criminal purposes. The aim of this work is to explore the possibilities and develop and test light and flexible protective shields based on modern nanomaterials, which will serve as an effective passive protection of electronic devices against remote eavesdropping. For this purpose, new composite materials based on electrically conductive nanoparticles with magnetic properties will be prepared. The possibilities of their compatibility with the carrier, chemical structure and morphology, mechanical, electrical and magnetic properties and methods and the possibilities of their processing into the required shape and form suitable for use in miniature electronics will be studied. The experiments will also include testing passive shields in simulated and real conditions and evaluating their ability to dampen electromagnetic waves emitted by electronic devices.
Contact supervisor
Study place:
Department of Mathematics, Informatics and Cybernetics, FCE, VŠCHT Praha
Development of renewable conductive hydrogels for flexible energy storage systems
AnnotationTo power wearable electronic devices, diverse flexible energy storage systems have been developed to operate under consecutive bending, stretching, and even twisting conditions. While supercapacitors and batteries are deemed as the most promising energy/power sources for wearable electronics, ensuring their electrochemical sustainability and mechanical robustness is crucial. Electrically conductive renewable hydrogels, amalgamating the electrical properties of conductive materials with the unique features of renewable hydrogels, provide an ideal framework for designing and constructing flexible supercapacitors and batteries. This project will focus on the development of novel functional hydrogels from renewable sources with controllable size, composition, morphology, and interface properties. A fundamental understanding of the relationships between chemical composition, structure, interface properties, stress, electrical conductivity, and electrochemical properties of conductive hydrogels will be undertaken. The effective application of these conductive hydrogels in flexible energy storage systems will be assessed.
Contact supervisor
Study place:
Department of Mathematics, Informatics and Cybernetics, FCE, VŠCHT Praha
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Updated: 25.3.2022 18:16, Author: Jan Kříž