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Smart hybrid gels
Strachota, Beata Katarzyna ; Matějka, Libor (advisor) ; Matějíček, Pavel (referee) ; Krakovský, Ivan (referee)
This Thesis is dedicated to the development of mechanically reinforced thermoresponsive hydrogels, able of fast and extensive temperature-induced volume transition. Poly(N-isopropylacrylamide)- (PNIPA-) based hydrogels crosslinked with Laponite clay nano-platelets, which are known for their extraordinary mechanical properties, were synthesized by free radical polymerization of the NIPA monomer in the presence of exfoliated clay nanoplatelets. In this work, the crucial role of the employed redox initiators in the formation of the physical PNIPA/clay network was established, and the particular processes taking place during the polymerization and network structure formation were described. The correlation of the time-dependent NIPA monomer conversion and of the observed structure-formation stages made possible to propose a general mechanism of the PNIPA/clay hybrid gel formation. Generally, a considerable attention was paid to the investigation of the formation-structure-property relationships. This knowledge makes it possible to control the structure evolution and hence the final material properties of the gels. An important part of this work is dedicated to the study of mechanical properties of the PNIPA/clay nanocomposite hydrogels and of the parameters which control them. The gained knowledge of...
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Self-assembling hybrid nanomaterials
Rodzeń, Krzysztof ; Strachota, Adam (advisor) ; Svoboda, Jan (referee) ; Matějíček, Pavel (referee)
Organic-inorganic polymer hybrids containing butyl stannoxane dodecamer cages (Sn_POSS) as nano-building blocks were prepared and investigated. Sn_POSS was employed as a linear, crosslinking or non-bonding molecularly blended unit. For this purpose, it was synthesized with two acrylamido, primary- or secondary amino, or with two additional non- functional groups, which were attached via ionic-bonded sulfonate substituents. The nano- building block was then incorporated in matrices such as PS, PAOS, PETA, PEMA, PHEMA and PPO-based epoxies (the latter with different mesh sizes). Sn_POSS reinforces the studied matrixes by filler-filler interactions (self-assembly to nano-domains). Specific interactions of the ionic bonds of Sn_POSS with suitable pendant groups of the matrixes also can generate reinforcement and suppress filler aggregation. Moreover, the Sn_POSS can undergo several types of chemical reactions like heat-induced oligomerization, dissociation of the ionic substituents, acidolysis of the Sn-butyl bonds, as well as radical reactions of the latter. The influence of ionically bonded cages on the hybrids' morphology, as well as their ability of dissociation and short-distance migration in the polymer network at elevated temperature, was evaluated by TEM, IR and NMR analyses. The mechanical...
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Liability for defects in business transactions
Matějíček, Pavel ; Eichlerová, Kateřina (advisor) ; Čech, Petr (referee)
The topic of this thesis is liability for defects in business transactions, or using the terminology of the effective Civil Code, obligations from non-performance. Rights from non- performance are one of the most important legal instruments regarding liability, together with liability for damage and liability for delay, all arising from pecuniary contracts, mainly from purchase contracts and contracts for work. With respect to the elapsed recodification of civil law, obligations arising from non- performance are no longer subject to two codes (in Act No. 40/1964 Coll., Civil Code and in Act No. 513/1991 Coll., Commercial Code), they are now governed only by Act No. 89/2012 Coll., the effective Civil Code. Civil code and its provisions are therefore the main part of this thesis. Moreover, some parts of the thesis contain comparison of the effective Civil Code to the preceding legislation, i.e. the Commercial Code, and to some international treaties as well. The first chapter, which follows right after the preface, contains sources of this thesis. The second chapter deals with the concept of obligations arising from non-performance, compares them to other areas of civil law dealing with liability, and later deals with the concept of commercial obligation. The third chapter talks about the provisions...
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Preparation of hybrid nanoparticles based on interaction of block polyelectrolytes with atypical ions
Mesíková, Soňa ; Matějíček, Pavel (advisor) ; Štěpánek, Miroslav (referee)
The Thesis deals with the co-assembly behaviour of cationic diblock copolymers poly(2- vinyl pyridine)-b-poly(ethylene oxide), P2VP-b-PEO, and poly(ethylene oxide)-b-poly(2- (N, N, N′, N′-tetramethyl guanidinium) ethyl acrylate), PEO-b-PGEA, with closo- dodecaborate anion, [B12H12]2- , in aqueous solutions. Formation of stable PEO-b- PGEA/[B12H12] nanoparticles was investigated by static and dynamic light scattering and 1 H NMR spectroscopy, and they were visualized as spherical nanoparticles by cryo- TEM imaging. According to the NMR results, both studied diblock copolymers form core- corona micelles with dodecaborate. The micellar molar mass and the aggregation number of PEO-b-PGEA/[B12H12] micelles were obtained in water and 0.156 M NaCl solution by standard Zimm method. For this, refractive index increment was evaluated by refractometer. The studied nanoparticles are promising for the boron delivery in medicine.
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Hybrid Nanostructures Containing Boron Compounds
Li, Jianwei ; Matějíček, Pavel (advisor) ; Olejniczak, Agnieszka (referee) ; Sedláková, Zdeňka (referee)
Boron cluster compounds (BCCs) are inorganic polyhedral structures. Their unique properties such as high chemical & thermal stability, three-center two-electron bonds, and three- dimensional aromaticity have drawn great attention. Incorporation of BCCs into polymers via covalent bonds or noncovalent interactions are extensively investigated in the recent decades. BCC-containing polymeric materials have been widely reported in the biological applications such as BNCT and enzyme inhibitors, and energy storage for example Li-ion batteries and solution-based Mg batteries. This dissertation is focused on the preparation and characterization of BCC-containing polymeric materials. The synthesized BCC-containing polymeric materials are also evaluated by in vitro experimental for biomedical applications or Li-ion mobility for Li-ion batteries studies. The ideas are to maximally simplify the preparation steps of BCC-containing polymers and deeply understand the physical chemistry properties of BCCs in these materials. Therefore, the studies can be generally divided into two parts: (i) Design of boron-containing hybrid systems. For biological applications, the corresponding BCC-containing polymeric materials must be water-soluble or form stable nanostructures in aqueous solutions. We performed a feasible...
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Pharmacokinetics of Intramuscularly Administered Thermoresponsive Polyacrylamides
Groborz, Ondřej ; Hrubý, Martin (advisor) ; Matějíček, Pavel (referee)
6 Pharmacokinetics of Intramuscularly Administered Thermoresponsive Polyacrylamides Author: Ondřej Groborz Supervisor: doc. Mgr. Martin Hrubý, Ph.D., DSc. Institute of Macromolecular Chemistry, Czech Academy of Sciences Advisers: Ing. Pavel Švec RNDr. Lenka Loukotová, PhD. Abstract Polymer solutions with lower critical solution temperature (LCST) undergo a phase separation when heated above their cloud point temperature (TCP). These thermoresponsive polymers have numerous promising medicinal applications, such as in situ depot-forming radiotherapy (brachytherapy), controlled drug-release, immuno-radiotherapy, injectable thermogelling for tissue engineering and cell culture and magnetic resonance imaging (MRI), among others. Yet, despite extensive research on medicinal applications of thermoresponsive polymers, their fate after their administration remains largely unknown. Thus, in our study, we synthesized and thoroughly characterized four different thermoresponsive polyacrylamides, namely poly(N-(2,2-difluoroethyl)acrylamide), poly(N- isopropylacrylamide), poly(N,N-diethylacrylamide) and poly(N-acryloylpyrrolidine) under physiologically relevant conditions. Subsequently, we determined their biodistribution kinetics in mice and proposed a data-based pharmacological model to describe their in vivo behaviour,...
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Boron cluster compounds as building blocks in supramolecular chemistry
Steiner, Filip ; Matějíček, Pavel (advisor) ; Strachota, Adam (referee)
The aim of this bachelor thesis was to get used to with the basics of boron chemistry, especially the exoskeletal derivatization of boron cluster compounds. Exoskeletal substitution of the closo-dodecaborate anion [B12H12]2- , which proceeds by the electrophile induced nucleophilic substitution (EINS) mechanism, provided a derivative containing a cyclic oxonium ring which was subsequently opened by reaction with alcohols (1-dodecanol, 1-octanol). The prepared compounds were characterized by 1 H, 13 C and 11 B NMR spectroscopy and MALDI-TOF mass spectrometry. The compounds will be used as building blocks for preparation of novel nanostructures via supramolecular chemistry approaches.
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Design of boron cluster-containing nanostructuresin solution
Fernandez Alvarez, Roberto ; Matějíček, Pavel (advisor) ; Machalová Šišková, Karolína (referee) ; Cígler, Petr (referee)
Thesis The main objective of this thesis is the study of boron cluster compounds in solution, their interaction with polymers and the formation of nanostructures. Most of the work was focused around cobalt bis(dicarbollide) (COSAN) but the incorporation of carborane into polymers was also studied. The idea was to close the knowledge gap around the way COSAN aggregates and continue the line of the laboratory in leading this topic. Therefore, we performed in-depth analysis of isothermal titration calorimetry curves to determine the aggregation number at concentrations around the critical micellar concentration (CMC). Thus, the aggregation number obtained was an improvement over previous data obtained a much higher concentration. The use of acetonitrile as a cosolvent in the micellization process helped formulate a model describing how C-H bonds in the COSAN micelles are directed towards the inside of the micelle. Furthermore, COSAN was used as a model drug for loading nanocarriers composed of hydrophobic core and charged corona. The importance of this work relies on the creation of guidelines for drug loading into similar polymeric vectors in order to determine how the nanocarrier will be affected. With the help of coarse-grained simulations, we determined that changes in the hydrophobicity of the...
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Self-Assembled Polymer Systems Based on Poly[(N-2,2-difluoroethyl)acrylamide] as Diagnostic and Theranostic Tracers for 19F Magnetic Resonance Imaging
Kolouchová, Kristýna ; Hrubý, Martin (advisor) ; Matějíček, Pavel (referee) ; Poučková, Pavla (referee)
In this doctoral thesis we describe a series of stimuli-responsive polymers which could be used as diagnostic tools or as smart drug delivery systems with simultaneous diagnosis (theranostics). All hereby mentioned polymers are thermoresponsive copolymers of (N-2,2-difluoroethyl)acrylamide exhibiting lower critical solution temperature in aqueous milieu. This means that they are water-soluble at low temperature while when heated above a certain temperature, they self-assemble into nano- or macro- sized assemblies. Because of the high concentration of fluorine atoms, all these polymers could be used as 19 F MRI tracers. We designed multiple different thermoresponsive, thermo- and pH-responsive, thermo-and reactive-oxygen-species-responsive polymers that could find numerous discussed applications in human medicine. We investigated their physico-chemical properties with 1 H and 19 F nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), elemental analysis, dynamic light scattering (DLS), static light scattering (SLS), small angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and turbidimetry. After the physicochemical optimization of the parameters for the selected applications, their biocompatibility was tested in vitro. Several promising polymers were tested in vivo...
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