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Preparation and characterization of nanoparticles formed by polymer-surfactant complexes
Dvořák, Filip ; Štěpánek, Miroslav (advisor) ; Netopilík, Miloš (referee)
In this work, copolymers of celulose-g-polystyrene (cel-PS) and celulose-g- poly(methylmetacrylate) (cel-PMMA) were characterized using static and dynamic light scattering, transmission electron microscopy and atomic force microscopy. Preparation of nanoparticles of these hydrophobic copolymers in aqueous solution was further studied, by means of precipitation from dioxane solutions using water with added low-molar-mass surfactants sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTMAB). It was shown that the ability of the surfactants to stabilize polymer nanoparticles is driven not only by the hydrophobic effect, but it depends also on specific interactions of the polar group of the surfactant with the surface of the nanoparticles. On the basis of the finding that the efficiency of stabilization of cel-PS copolymers is much higher than in case of linear PS, it can be concluded, that the branched structure of copolymers is favorable for the formation of hydrofobically stabilised polymer-surfactant complexes.
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Physically-based Cloud Rendering on GPU
Elek, Oskár ; Wilkie, Alexander (advisor) ; Křivánek, Jaroslav (referee)
The rendering of participating media is an interesting and important problem without a simple solution. Yet even among the wide variety of participating media the clouds stand out as an especially difficult case, because of their properties that make their simulation even harder. The work presented in this thesis attempts to provide a solution to this problem, and moreover, to make the proposed method to work in interactive rendering speeds. The main design criteria in designing this method were its physical plausibility and maximal utilization of specific cloud properties which would help to balance the complex nature of clouds. As a result the proposed method builds on the well known photon mapping algorithm, but modifies it in several ways to obtain interactive and temporarily coherent results. This is further helped by designing the method in such a way which allows its implementation on contemporary GPUs, taking advantage of their massively parallel sheer computational power. We implement a prototype of the method in an application that renders a single realistic cloud in interactive framerates, and discuss possible extensions of the proposed technique that would allow its use in various practical industrial applications.
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Self-Assembly in Mixture of Surfactants and Stimuli-Responsive Polymers with Complex Architecture
Bogomolova, Anna ; Filippov, Sergej (advisor) ; Štěpánek, Miroslav (referee) ; Hanyková, Lenka (referee)
Title: Self-assembly in mixture of surfactants and stimuli-responsive polymers with complex architecture Author: Anna Bogomolova Department: Physical and Macromolecular Chemistry Supervisor: PhD. Sergey K. Filippov, IMC AS CR, v.v.i. Supervisor's e-mail address: filippov@imc.cas.cz Abstract: The issue of construction of complex multi-block copolymers is currently one of the most researched areas. It became a logic consequence of the continuous development in polymer chemistry. Nowadays, a great interest is attracted to multi- responsive block copolymers. As a rule, they consist of hydrophilic, hydrophobic and responsive blocks. That responsive block can be either thermo-sensitive or pH-sensitive as well as sensitive to some other external stimuli. In the present work, we will try to cover topic of stimuli-responsive block copolymers and their interactions with different types of surfactants. Understanding of polymer/surfactant interactions can be a crucial step for future modeling of drug/polymer or protein(DNA)/surfactant interactions. There is a great interest in the investigation of polymer-surfactant interactions. However, while the homopolymer-surfactant interactions are characterized well enough, the same interactions for block copolymers are poorly described. The main development in the latter topic...
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Nanoparticles based on complexes of hydrophilic block polyelectrolytes and new gemini ionic surfactants
Šomšáková, Katarína ; Uchman, Mariusz Marcin (advisor) ; Trhlíková, Olga (referee)
This bachelor thesis deals with preparation and study of the aqueous solutions of block polyelectrolyte poly(2-vinylpyridine)-b-poly(ethylen oxide), P2VP-PEO with gemini surfactants 6,6'-(ethan-1,2-diylbis(oxy)) bis(3-dodecylbenzenesulfonate acid), 6,6'- (buthan-1,4-diylbis(oxy)) bis(3- dodecylbenzenesulfonate acid) and 6,6'-(hexane-1,6- diylbis(oxy)) bis(3- dodecylbenzenesulfonate acid) complexes and with P2VP-PEO and sodium dodecylsulfate, SDS, complexes, and compares their physico-chemical properties. Formed particles were characterized by static and dynamic light scattering, zeta potential, isothermal titration calorimetry and transmission cryo-electron microscopy. Even small amount of surfactant leads to coassembly of P2VP-PEO with surfactants, formed by PEO shell and P2VP/surfactant core. The nanoparticles of block polyelectrolyte and gemini surfactants in 0.1M HCl are stable and their size depends on the spacer lenght and the surfactant/polymer ratio.
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Beating Intracellular Bacterial Infections with Polymeric Nanobead-Based Interventions: Development, Structure Characterization, and Analysis
Trousil, Jiří ; Hrubý, Martin (advisor) ; Záruba, Kamil (referee) ; Kročová, Zuzana (referee)
One hundred years after the discovery of antimicrobials and antibiotics, intracellular bacterial pathogens remain a major cause of global morbidity and mortality. This is due to the complex and intricate ability of these pathogens to undergo intracellular replication while evading host cell immune defense. Bacterial agents such as Legionella pneumophila, Francisella tularensis, and Mycobacterium tuberculosis, as the causative agents of Legionnaires' disease, pulmonary tularemia, and tuberculosis (TB), respectively, contribute to this burden. Moreover, these agents are weaponizable pathogens due to their aerosolizability. TB represents a global health problem, although a potentially curative therapy has been available for approximately 50 years; this intracellular disease affects approximately 1 in 3 people worldwide, with over 10 million new cases per year and one death every three minutes. TB can usually be treated with a 6- to 9-month course of combined therapy. The necessity of using a cocktail of anti-TB drugs and the long-term treatment schedules required for conventional therapy, however, result in poor patient compliance; therefore, the risk of treatment failure and relapses is higher. Hence, improved drug delivery strategies for the existing drugs can be exploited to shorten the duration of TB...
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Synthesis and characterization of ABA triblock copolymers modified with glucose via thiol - ene click reaction
Hašpl, Adam ; Uchman, Mariusz Marcin (advisor) ; Štěpánek, Miroslav (referee)
The bachelor thesis is focused on method of postpolymerisation modification of two poly(ethylene oxid-b-1,2-butadiene-b-ethylene oxide) amphiphilic block copolymer samples with high content of 1,2-isomer units in inner polybutadiene block by thiolene click. The implemented modification agent was 1-thio-β-D-glucose tetraacetate. The thesis is further focused on methods of copolymer sample characterization before and after modification reaction. Structure and degree of functionalization of vinylic units in polybutadiene block after modification was determined by nuclear magnetic resonance spectroscopy. The dimensions of prepared polymeric particles were studied by static and dynamic light scattering methods. Keywords: ABA triblock copolymers, self-assembly, click reaction, NMR spectroscopy, light scattering
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Mucin hydrogels - artificial models of native mucus systems
Mikušová, Janka ; Obruča, Stanislav (referee) ; Sedláček, Petr (advisor)
The scope of this masters thesis is the preparation of a model mucin system and its utilization as an artificial model of the native mucus system. The creation of this model system, according to several designed methods was a part of experimental part of the thesis. The preparation of mucin system comprised of physical and chemical methods of hydrogel formation, screening and characterisation of the various physical conditions of the mucin properties on its molecular level, and the preparation of sorbent with sorption surface containing mucin. Methods of light scattering, namely dynamic light scattering (DLS), used for mucin particles size change monitoring, and electroforetic light scattering (ELS), used for Zeta potential change monitoring, were used for the screening of the impact of physical factors on the properties of mucin.For the characterisation of impact of the temperature on changes in mucin sctructure was, apart from monitoring of light scattering, used also a diferential scanning calorimetry (DSC), which registered temperature value, at which mucin thermal denaturation occurs. In the next part of the thesis we subdued the created sorption surfaces to various physical-chemical analyses, which task is the characterisation and projection of surface and confirmation of mucin presence.Substancial part in monitoring and characterisation of changes in surface sctructure of sorption surface was accomplished by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscophy (SEM) was used for the final, more detailed, projection of the mucin enriched, sorbent surface structure. Suggested methods of mucin hydrogel, didnt prove sufficient results for the possibility of application of hydrogel as a artificial model of real mucus system, but the sorbent application was indicated as a suitable alternative and an instrument for the further mucin behaviour research and possibly subsequent bacterial adhesion, which represents the first step in the formation of the bacterial biofilm.
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The study of the self- and co-assembly of block copolymers and block polyelectrolytes
Raya, Rahul Kumar ; Procházka, Karel (advisor) ; Štěpánek, Petr (referee) ; Šachl, Radek (referee)
The Thesis describe my studies based on self-assembly and co-assembly of block copolymer micelles that I conducted at the Department of Physical and Macro- molecular Chemistry at the Charles University, Prague in the research group of my supervisor, Prof. Dr. Karel Procházka, DrSc. The Thesis based on my publications and consists of four parts. Here I studied the formation of polymeric nanoparticles in aqueous solutions formed by polyelectrolytes with hydrophobic backbones by a combination of several experimental methods. The achieved results enabled me to explain the structure and properties of studied self- and co-assembled nanoparticles and to outline the decisive trends of their behavior. The spontaneous formation, sol- ubility and stability of complex nanoparticles depend not only on the electrostatic attractive forces but also on the hydrophobic effects. As the enthalpy-to-entropy interplay is very complex, a number of external factors such as temperature, pH, salinity and concentration affect the assembling process and structure of formed nanoparticles. 1
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