open positions

PhD fellow in "Stabilization of metal clusters on the zeolite supports and their assessment by in-situ electron microscopy methods"

Project summary:

Metal nanoparticles immobilized at zeolite supports are important class of heterogenous catalysts for hydrogenation and dehydrogenation, reforming, and water-gas shift reactions. Zeolites, porous elementosilicates, are used to encapsulate metal nanoparticles to improve their stability. Currently, in-situ encapsulation and post-synthesis functionalization are two main synthesis strategies for metal incorporation in zeolites. Zeolites are often prepared as 3D solids; however, some topologies have layered representatives. Direct exfoliation of zeolites into suspension of monolayers has widened the spectrum of novel zeolitic supports for functionalization, thus design of new catalysts.

The main objective of the thesis will be:

preparation of zeolites, including layered precursors;
functionalization of prepared supports with metal clusters;
characterization of prepared materials by advanced, in-situ electron microscopy techniques;
optimizing the synthesis procedure to achieve better stability of prepared catalysts; and
catalytic tests of prepared materials and investigation of metal stability under reaction conditions.

We are looking for motivated students with experience in synthesis and heterogenous catalysis.

The experience in transmission electron microscopy will be an advantage.

PhD fellow in "Synthesis of novel zeolites and their structure determination by advanced electron diffraction"

Zeolites are porous elementosilicates with vast applications in the fields of catalysis, sorption, and ion-exchange. Their advantage lies in properties, such as high adsorption capacity, defined microporosity (resulting in molecular sieving effect), adjustable chemical composition, and possibility for post-synthesis modifications. Conventional synthesis of zeolites uses solvothermal methods that are limited in term of control and design of the process. On the contrary, recently developed ADOR synthesis approach (Assembly, Disassembly, Organization, Reassembly) gives the possibility to design the final products and prepare different type of porous materials by post-synthesis manipulations (using 2D zeolite precursors) or removal of specific building units from the parent material. Design and synthesis of novel zeolitic materials and their advanced characterization by electron microscopy and electron diffraction methods are general aims of proposed PhD thesis. The synthesized materials will be investigated for their potential use e.g. in catalysis.

The PhD work will include:

the application of established synthetic techniques (e.g. solvothermal synthesis, ADOR approach, swelling, pillaring, and functionalization,
development of novel synthesis strategies, and
characterization of synthesized material by electron microscopy and diffraction methods (including novel techniques like Continuous Rotation Electron Diffraction (cRED).

The PhD work will result in preparation of new zeolitic materials and their structure determination by advanced characterization methods.

The experience in electron microscopy and zeolite synthesis will be an advantage for the potential candidate.

PhD fellow in Rational synthesis of zeolitic materials and their characterization by advanced electron microscopy methods

Project summary

Zeolites are among the most useful materials in catalysis, sorption and ion-exchange. It is due to their properties i.e. high adsorption capacity, defined microporosity (resulting in molecular sieving effect), adjustable chemical composition, and possibility for post-synthesis modifications. Conventional synthesis of zeolites is performed by solvothermal methods that are limited in term of control and design of the process. On the other hand, recently developed ADOR synthesis approach (Assembly, Disassembly, Organization, Reassembly) utilizing the 2 dimensional (2D) layered zeolite precursors gives the possibility to design the final product and prepare different type of porous materials by post-synthesis manipulations. The rational design of novel zeolitic materials and their characterization by advanced electron microscopy methods are general aims of proposed PhD thesis. The synthesized materials will be investigated for their potential use e.g. in catalysis, especially for acid-catalysed reactions. The PhD work will include: 1) the application of established synthetic techniques (e.g. solvothermal synthesis, ADOR approach, swelling, pillaring, and functionalization, 2) development of novel synthesis strategies, and 3) characterization of synthesized material by electron microscopy and diffraction methods (including novel techniques like Rotation Electron Diffraction (RED). The PhD work should result in preparation of new zeolitic materials and their better understanding by use of advanced characterization techniques.

Five relevant publications of the research group

Wieslaw J. Roth, Petr Nachtigall, Russell E. Morriss, Paul S. Wheatley, Valerie Seymour, Sharon E. Ashbrook, Pavla Chlubná, Lukáš Grajciar, Miroslav Položij, Zrnošt Zukal, Oleksiy Shvets, Jiří Čejka, "A family of complex zeolites with controlled pore size prepared through a 'top down'method", Nature Chemistry, 5 (2013) 628.

Pavla Eliášová, Maksym Opanasenko, Paul Wheatley, Mariya Shamzhy, Michal Mazur, Petr Nachtigall, Wieslaw J. Roth, Russell E. Morris, Jiří Čejka, “The ADOR mechanism for the synthesis of new zeolites”, Chemistry Society Reviews, 44 (2015) 7177.

M. Mazur, P. S. Wheatley, M. Navarro, W. R. Roth, M. Polozij, A. Mayoral, P. Eliasova, P. Nachtigall, J. Cejka, R. E. Morris, “Synthesis of ‘unfeasible’zeolites”, Nature Chemistry, 8 (2016) 58-62.

M. Mazur, V. Kasneryk, J. Přech, F. Brivio, C. Ochoa-Hernández, A. Mayoral, M. Kubů and J. Čejka, “Zeolite framework functionalisation by tuneable incorporation of various metals into the IPC-2 zeolite”, Inorganic Chemistry Frontiers, 2018, 5, 2746-2755.

S. E. Henkelis, S. A. Morris, M. Mazur, P. S. Wheatley, L. N. McHugh and R. E. Morris, “Monitoring the assembly–disassembly–organisation–reassembly process of germanosilicate UTL through in situ pair distribution function analysis”, Journal of Materials Chemistry A, 2018, 6, 17011-17018.

Current research grants of the group

EXPRO GAČR (19-27551X)

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PhD fellow in Rational design of hierarchical zeolites for the synthesis of fine chemicals

Project summary

Due to such useful characteristics as molecular sieving effect, high adsorption capacity, adjustable chemical composition zeolites are efficient catalysts of a number of large-scale processes. At the same time, despite showing unique and extremely useful properties, micropores impose restrictions on the mass transport of bulky reactants limiting the use of conventional zeolites in fine chemical or pharmaceutical synthetic applications. Last decade has brought a number of different strategies to accomplish the synthesis of zeolites with additional mesoporosity, i.e. hierarchical zeolites. The advantageous features of hierarchical zeolites (e.g. multilevel porosity, high concentration of acid sites with tunable strength) can be used to further extend the potential of zeolites to new applications in catalysis. The rational design of novel hierarchical (micro-mesoporous) zeolitic materials for catalytic applications is a general aim of proposed PhD thesis. The work will include both 1) the application of well-known synthetic techniques (e.g. removing of framework atoms) allowing fabrication hierarchical materials to novel objects (e.g. Ge-containing zeolites) and 2) further development of innovative approaches invented during last decade. This shall result in the preparation of a broad range of structurally and chemically diversified hierarchical zeolites followed by thorough investigation of structure – acidity – catalytic activity relationship in a set of acid-catalyzed reactions.

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PhD fellow in Hybrid Nanostructures Based on Polymer-Ions Interaction

Project summary

Highly charged molecules and nano-assemblies serve as unique building blocks in nanochemistry. Bulky and multivalent ions are known to readily condense on polyelectrolyte chains or brushes. Such ions are therefore capable to co-assemble with double-hydrophilic block copolymers into core/shell nanoparticles. It brings new function into the system and also introduces sensitivity to external stimuli, both depending on the nature of the charged specie. Besides co-assembling with polymers, a structure of hydration shell and a propensity of ions to specific interactions are interesting per se. It can lead to a complex solution behavior and the corresponding formation of nano-aggregates.

Skills in nanochemistry and synthetic chemistry are welcomed!

Three relevant publications of the research group

Fernandez-Alvarez R., Dordovic V., Uchman M., Matejicek P.: Amphiphiles without Head-and-Tail Design: Nanostructures Based on the Self-Assembly of Anionic Boron Cluster Compounds. Langmuir 2018, 34, 3541-3554.

Dordovic V., Uchman M., Reza M., Ruokolainen J., Zhigunov, A., Ivankov O.I., Matejicek P.: Cation-sensitive compartmentalization in metallacarborane containing polymer nanoparticles. RSC Advances 2016, 6, 9684–9892.

Uchman M., Dordovic V, Tosner Z., Matejicek P.; Classical Amphiphilic Behavior of Nonclassical Amphiphiles: A Comparison of Metallacarborane Self-Assembly with SDS Micellization. Angewandte Chemie-International Edition 2015, 54, 14113–14117.

Current research grants of the group

Czech Science Foundation grants: 17-00648S “Chaotrope, hydrotrope or surfactant? Anionic boron cluster compounds in water and in complexes with polymers” ends in 2019, and 19-13458S “Nanomaterials based on co-assembly of triblock copolymers with macroions and other atypical ions” 2019-2021.

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PhD fellow in Sugar and pH-responsive multicompartment nano-assemblies for dual-drug solubilization and delivery

Project summary

The concept of Multicompartment Micelles (MCMs), i. e., self-assembled aggregates with moieties of different chemical properties, that mimic biological molecules such as proteins was derived by Prof. H. Ringsdorf almost twenty years ago and theoretically described by de Gennes. Figure 1 represents a rather futuristic view of multifunctional smart nanoparticles that possess various sub-domains and functions that coexist and perform in close proximity without mutual interference or with controlled interactions, as it works in nature. The self-assembly process of amphiphilic polymers in water is an attractive platform for preparation of such multi-compartment nanoparticles, due to the mutual incopatibilities of the polymers involved.

The overall goal of this proposal is to gain new information on nanostructure and dynamics of newly designed MCMs based on biodegradable and biocompatible ABC triblock terpolymers. The most often used ABC terpolymers in the research of the MCMs consist of highly incompatible hydrocarbon and fluorocarbon blocks that ensure compartmentalization of nanoparticles, however the lack of responsive functional groups to biologically relevant environment is the main drawback of such MCMs. Much less is known about MCMs that contains hydrocarbon blocks only and boronic acid derivatives. This is why we will focus on synthesis and self-assembly of new ABC triblock terpolymers having at least one boronic acids (bezoxaborol or Wulff-type boronic acids) containing block combined with a hydrophilic and hydrophobic one. By incorporating boronic acids, amphiphilic nanoparticles can be prepared that reversibly bind to 1,2- or 1,3- diols and catechol-containing molecules as well as they are responsive to subtle changes in solution pH (relevant in cancer therapy) and saccharide concentration (relevant for diabetes - related applications). In addition the hydrophobic core forming block will accommodate hydrophobic drugs or fluorophores. The neutral hydrophilic block forms the stabilizing corona of the micelles.

The subdivided core of MCMs serves as a microcontainer for a variety of different active agents. This is why the next goal is to broaden the knowledge on selective solubilization of aromatic compounds (drugs) and their sequential release from MCMs to achieve a synergistic antitumor effect and improve the therapeutic index. Fluorescence techniques will allow us to provide information on local physicochemical properties like micropolarity, microviscosity, local electrostatic potential or accessibility of the fluorophore’s (drugs) neighborhood by certain molecules like quenchers.

Profile of an ideal candidate

Good knowledge of English (FCE equivalent or better)

Background in polymer chemistry and/or phenylboronic acid synthesis and characterization

Experience with scattering techniques, drug solubilisation and delivery

Publications

Glucose-Responsive Hybrid Nanoassennblies in Aqueous Solutions: Ordered Phenylboronic Acid within Intermixed Poly(4-hydroxystyrene)-block-poly(ethylene oxide) Block Copolymer By: Matuszewska, Alicja; Uchman, Mariusz; Adamczyk-Wozniak, Agnieszka; et al. BIOMACROMOLECULES
- Volume: 16 Issue: 12 Pages: 3731-3739 Published: DEC 2015

Preparation of lactic acid- and glucose-responsive poly(epsilon-caprolactone)-b-poly(ethylene oxide) block copolymer micelles using phenylboronic ester as a sensitive block linkage By: Vrbata, David; Uchman, Mariusz NANOSCALE
- Volume: 10 Issue: 18 Pages: 8428-8442 Published: MAY 14 2018

Current research grants of the group

Czech Science Foundation grunt no. 17-00289Y: Sugar and pH-responsive multicompartment nano-assemblies for controlled drug solubilization and release

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PhD fellow in Theoretical studies of endohedral fullerenes

Endohedral fullerenes, i.e. cage-like hollow carbon molecules with an atom or a small molecule trapped inside, are fascinating species with unusual properties attractive for applications. With Gd atom inside they can serve as MRI contrast agents, with a radioactive metal as radiotracers, with N atom as q-bits in quantum computers, with metal nitrides as materials for organic solar cells, etc. The applications, however, are hindered by high costs of preparation of these compounds and too many possible combinations of fullerenes and encapsulated species. For these reasons the theoretical predictions can be particularly valuable.

The goal of this Ph.D. project is to obtain structural, spectral, thermodynamic and kinetic predictions by standard methods of quantum chemistry and statistical thermodynamics for several endohedrals, namely metallofullerenes studied experimentally by partner research groups, e.g., DOI: 10.1002/anie.201604121. Going beyond the standard calculations is also possible for an enthusiastic student, e.g. calculation of an inherently quantum motion of the encapsulated species by path-integral Monte Carlo methods (from the calculation of the potential to the simulational methodology).

Profile of an ideal candidate: M.Sc. or equivalent degree in Chemistry, Physics, Material Science or a related field (required), working communication skills in English, background in quantum chemistry, statistical thermodynamics and Unix-like operating systems.

PhD fellow in Modeling of weak polyelectrolytes interacting with multivalent ions.

Association of weak polyelectrolytes can be controlled by the variable pH-sensitive ionization of weak acid and base groups. Encapsulation of multivalent molecules in polyelectrolyte-based systems can be controlled by the same means. Release of the cargo molecules can be then triggered by a change of pH. For example, multivalent porphyrin derivatives can be encapsulated in polyelectrolyte micelles or interpolyeletrolyte complexes. Using coarse-grained molecular simulations, we will predict electrostatically controlled interactions in theses systems. The simulations will be used to guide experimental optimization of self-assembled polyelectrolyte systems investigated by the experimental team within the Soft Matter research group. The ultimate goal is to achieve rational design of these systems using a combination of simulations and experiments.

The prospective candidate should perform coarse-grained simulations of polyelectrolytes and interpolyelectrolyte complexes interacting with multivalent ions, and focused on ionization equilibria. He/she will use the open source simulation package Espresso [www.espressomd.org], and will implement data analysis routines for the specific problems investigated here. A contribution to development of the simulation package is also foreseen.

Current research grants of the group

Czech Science Foundation grant 19-10429S

Profile of an ideal candidate

MSc. or equivalent in Chemistry, Physics or a related field (required), good knowledge of English, background in Statistical Mechanics, Soft Matter, and Polymer Science. Experience with molecular simulations, programming and Linux.

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Project summary

Five relevant publications of the research group

Current research grants of the group

Project summary

Project summary

Three relevant publications of the research group

Current research grants of the group

Project summary

Project summary

Profile of an ideal candidate

Publications

Current research grants of the group

Current research grants of the group

Profile of an ideal candidate

Physchem.cz

Open Positions

Open postdoc and PhD positions

PhD fellow in "Stabilization of metal clusters on the zeolite supports and their assessment by in-situ electron microscopy methods"

PhD fellow in "Synthesis of novel zeolites and their structure determination by advanced electron diffraction"

Assistant Professor position in experimental Physical chemistry

Postdoc position in Catalysis

Postdoc position in Synthesis of two-dimensional materials

Postdoc position in Synthesis of zeolites

PhD fellow in Rational synthesis of zeolitic materials and their characterization by advanced electron microscopy methods

Project summary

PhD fellow in Rational design of hierarchical zeolites for the synthesis of fine chemicals

Project summary

PhD fellow in Hybrid Nanostructures Based on Polymer-Ions Interaction

Project summary

PhD fellow in Operando computational modelling of materials

Project summary

PhD fellow in Sugar and pH-responsive multicompartment nano-assemblies for dual-drug solubilization and delivery

Project summary

PhD fellow in Theoretical studies of endohedral fullerenes

PhD fellow in Modeling of weak polyelectrolytes interacting with multivalent ions.

Postdoc in Association of Block-Copolymers Containing Weak Polyelectrolytes