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Influence of polyelectrolyte biopolymers on transport of ions
Kolesa, Pavel ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
This bachelor thesis was focused on the study of interaction of cationic biopolymer with model diffusion probe (basic organic dye) in the gel media by diffusion processes. The main aim was optimization of simply laboratory diffusion technique (unsteady diffusion in a cuvette) because of study on interactions of chosen biopolymer with model compound depending on temperature. Cationic chitosan was chosen as model biopolymer. The model diffusion compound was chosen organic anionic dye Acidal Black 10B (C.I. 20470). Diffusion processes in plastic cuvettes were realized by transport of dye in a hydrogel media based on thermoreversible polysaccharide – agarose. The important content of this method is a monitoring of the time progression of diffusion profile by UV-VIS spectrophotometry. Important part of this work was characterization of hydrogel medium and biopolymers by basic physical-chemical methods. This bachelor thesis is focused on reactivity of chitosan and its behavior in different systems. Unsteady diffusion in cuvettes appears to be a universal method for the study on reactivity of biopolymers.
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Stability of Soil Organic Matter
Heldesová, Michaela ; Doskočil, Leoš (referee) ; Kalina, Michal (advisor)
This bachelor thesis summarizes available information about current research of soil organic matter stability and it divides them into two logical units. The first part includes environmental, physical and chemical factors, including human activities, which affect the stability or decomposition of soil organic matter. The methods used for the study of organic matter in the soil are summarized in the second part of this thesis. There the attention is paid to the accumulation of organic matter in specific pools, the ways of extraction of organic compounds and the use of quantitative and qualitative analytical methods to describe various characteristic of organic matter.
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The Study of Aggregation of Humic Acids in Different Xenobiotic Environments
Hronová, Aneta ; Smilek, Jiří (referee) ; Kalina, Michal (advisor)
Theme of the presented bachelor thesis is the study of the aggregation behavior of the humic acids (HA) in the environment of extraneous substances. As extraneous substances, three cationic surfactants were selected (CTAB, TTAB and Septonex). In the experimental part of the thesis, the humic acids were characterized in detail using different methods (elemental analysis, ash content determination, titration acidity determination). The experimental part of the thesis is dealing with the structure of created HA-surfactant systems. These systems were characterized using the results of the elemental analysis and FT-IR spectroscopy. The key part of the experimental part of the study is represented by the selection of proper methods and by determination of the critical aggregation concentration of the humic acids in the surfactant environment. For these purposes, two key methods were selected in the frame of the presented bachelor thesis: isothermal titration calorimetry and dynamic light scattering. The first method is sensitive owing to the energetic fluctuations, in the case of the dynamic light scattering we are able to detect well the changes in the particle size caused by mutual interactions of particular substances in the system.
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Study on Reactivity of Cationic Biopolymer by Simple Diffusion Techniques
Tesařová, Barbora ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis is focused on study of chitosan reactivity by simple diffusion processes realized in hydrogel media based on agarose. Mechanical properties studied by oscilatory measurements and the pore size were determined at agarose gels with the addition of chitosan as the main parameters influenced the transport properties. The main goal of this work is the investigation the reactivity of chitosan. Agarose is used only as a supporting matrix for the formation of a hydrogel. The state of the art is aimed primarily on the study of chitosan reactivity based on already published scientific papers.
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The Study of Biopolymers Stability Using Light Scattering Techniques
Kratochvíl, Zdeněk ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
The stability of chosen biopolymers (or simple carbohydrates and amino acids) was in-vestigated using light scattering methods. Samples were prepared by dissolving the sub-stance in deionised water or in diluted acetic acid. Firstly, the effect of increasing concen-tration on zeta potential was observed and the optimal concentration for the next measure-ments was determined. Afterwards, the stability and the molecular weight of used sub-stances were studied during long-time storage in different time intervals. It was found out that chitosan, CMC, hyaluronate and sodium alginate were subjected to degradation whereas increase of the molecular weight and the zeta potential was observed in case of BSA. In the end, the samples were exposed to several different external effects, namely the influence of different temperatures, UV radiation and increasing ionic strength. The results showed that rather higher temperature has a significant impact on biopolymers stability. However, used biopolymers were hardly affected by UV radiation except BSA whose molecular weight increased considerably. Decrease of the zeta potential absolute values and the molecular size usually occurred with increasing ionic strength. The change of molecular weight was not detected.
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Transport properties of agarose hydrogels
Vlasák, Jan ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
This thesis deals with the transportation processes of electrolytes using simple organic dyes as diffuse probes. The main goal of the work concerns a study of a diffusion mobility of the selected probes being in a form of simple organic dyes in a hydro-gel matrix based on a thermo-reversible linear polysaccharide, i.e., agaroses, functioning as semi-permeable membranes. The thesis describe diffusion processes used for determination of the basic diffusion parameters such as an efficient diffusion coefficient, reputed diffusion coefficient, separating coefficient, concentration of the dye in a gel and the time needed for the diffusion going throughout the entire layer of the gel. Attention is paid also to the environment in which the diffusion processes are implemented (in particular in view of the gel-like samples), porousness of the structure and its mechanical properties.
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Characterization of liposomes as precursors for the preparation of models of cellular membrane using scattering techniques
Gjevik, Alžběta ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
The bachelor thesis presents a cellular membrane design based on lecithin, cholesterol and POPG basis. It summarizes formation mechanisms, optimization techniques and characterization methods of model cellular membranes. It focuses on preparation of liposomes with various lipid compositions as precursors for model membranes preparation and characterization. Small unilamellar liposomes were formed by thin layer evaporation, thin layer rehydration in phosphate buffer and sonication. Size and stability (-potential) of formed liposomes were measured using dynamic light scattering. Successful supported lipid bilayer formation on glass surface by vesicular fusion was tested using the most stable lipid composition. SLB was characterized by Z-scan fluorescence correlation spectroscopy.
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Preparation and Characterization of Drug Carrier Systems on the Basis of Magnetic Nanoparticles
Chvátalová, Barbora ; Burdíková, Jana (referee) ; Kalina, Michal (advisor)
This bachelor thesis deals with the study of magnetic nanoparticles, optimizing their preparation and stabilization. The nanoparticles with different ratios of Fe2+ and Fe3+ ions were prepared by coprecipitation by variously concentrated sodium hydroxide. Three samples of particles were selected and were further observed. Their stability in Milli-Q water, buffer, polyvinylalcohol, hyaluronic acid and chitosan was studied in function of time using methods of dynamic and electrophoretic light scattering. By UV-VIS spectrometry it was confirmed that the magnetic nanoparticles were actually prepared. Nanoparticles coated with chitosan and hyaluronic acid were then further characterized using FT-IR, XRD and SEM.
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Study on interactions of protonated aminoacids with low-molecular weight hyaluronan
Chlumská, Jana ; Kalina, Michal (referee) ; Chytil, Martin (advisor)
This bachelor thesis deals with interactions between hyaluronic acid (HA) of low molecular weight (110-130 kDa) and protonated aminoacids lysine and 6-aminocaproic acid. For investigation of these interactions, methods such as pH-metry, conductance measurement, viscometry and dynamic light scattering were used. The electrostacic interactions between carboxylic group of HA and the aminogroup of the aminoacids are presumed. Proving these interactions would allow us to physically modify HA and further more, using such a system as a carrier of pharmaceuticals. The interactions of protonated lysine with HA were studied in pure water or in the solution of NaCl (c = 15 mmol•dm-3). Interactions of 6-aminocaproic acid were studied only in pure water. Both aminoacids were in the concentration range 0.9-20 mmol•dm-3. The decrease in the viscosity of the solutions indicates the interactions for lysine; for 6-aminocaproic acid the interactions also occured, but not as signifciantly as for the system containing lysine.
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Diffusion of cupric ions in humic gel
Kalina, Michal ; Gregorová,, Eva (referee) ; Klučáková, Martina (advisor)
The bachelor´s thesis deals with the study of non–stationary diffusion of copper (II) ions in humic gel. The objective of the study was to validate that the diffusion is influenced by the volume of cupric ions solution and by the length of tubes filled with humic gel. Diffusion was characterized by the value of diffusion flux and by the copper (II) ionic concentration profiles in humic gel. The data necessary for calculation were obtained by spectrophotometric measuring of the extracts of each slice after diffusion.
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