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Preparation of nanoparticles and nanofibers for application in anti-acne products
Tilšarová, Kamila ; Veselá, Mária (referee) ; Skoumalová, Petra (advisor)
The diploma thesis was focused on the preparation and characterization of nanoparticles and nanofibres with active substances from chosen herbs with the aim to apply this materials to the products against acne. Various types of extracts were tested on the content of polyphenols, flavonoids and antioxidation activity. These extracts were encapsulated to the liposomes and fibres of polyhydroxybutyrate. Prepared liposomes and fibres were tested mainly on antioxidation activity and antimicrobial activity against the strain Propionibacterium acnes. Then, liposomes were applied to cosmetic emulsions. These creams reported high antioxidation activity and excellent stability determined by analytical centrifugation. Prepared nanofibres also reported high antioxidation activity and antimicrobial effect as well. Finally, particles and fibres were tested in contact with human cells. In appropriate concentration, there was no cytotoxic effect and tested materials can be used in applications on problems with acne.
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Study of organs of mice in inhalation experiments
Vrlíková, Lucie ; Diviš, Pavel (referee) ; Dočekal, Bohumil (advisor)
The diploma thesis is devoted to study potential risks for living organisms resulting from inhalation of nanoparticles of chosen heavy metals. The main aim of this work is the investigation of organs from experimental white mice after their guided inhalation of lead nanoparticles. The samples of liver and lungs from these animals are taken in time periods during the inhalation experiments and processed by specific methods for their evaluation. After pressurized microwave assisted decomposition of selected samples of mice organs in high purity concentrated nitric acid the content of lead is determined by atomic absorption spectrometry with electrothermal atomization. Furthermore, the changes are monitored using the microscopy of histological slides stained with hematoxylin-eosin. The results of both approaches are evaluated and compared within the frame of this work.
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Liquid aprotic electrolytes with TiO2 a Al2O3 nanoparticles
Tomeš, Petr ; Krejza, Ondřej (referee) ; Sedlaříková, Marie (advisor)
The first part of this diploma thesis is dealing with conductivity of liquid electrolytes. The second part is about third generation gel electrolytes and thein conductivity. The electrolytes were inorganic salts LiClO4, LiBF4 and NaClO4 in an aprotic propylene carbonate (PC) -used as a solvent. Nanosized Al2O3 and TiO2 particles were, proportionally to the sample's volume, added to the both – blend and gel samples in an amount expressed by weight percentage (wt). Both liquid and gel electrolytes contained following amount on nanosorbent: 3,46% wt, 7,17% wt, 10,0% wt and 12,0% wt. The liquid electrolytes were gelled using commercially available precursor Superacryl (Spofa dental s.r.o.).
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Effect of sub-micrometer structural features on rheology of polymer nanocomposites
Lepcio, Petr ; Chodák,, Ivan (referee) ; doc.Ing.Marián Lehocký, Ph.D. (referee) ; Jančář, Josef (advisor)
Polymerní nanokompozity (PNCs) mají slibnou budoucnost jako lehké funkční materiály zpracovatelné aditivními výrobními technologiemi. Jejich rychlému rozšíření však brání silná závislost jejich užitných vlastností na prostorovém uspořádání nanočástic (NP). Schopnost řídit disperzi nanočástic je tak klíčovým předpokladem pro jejich uplatnění ve funkčních kompozitech. Tato práce zkoumá přípravu polymerních nanokompozitů v modelové sklotvorné polymerní matrici roztokovou metodou, technikou schopnou vytvářet prostorové uspořádání nanočástic řízené strukturními a kinetickými parametry přípravného procesu. Prezentované výsledky popisují rozdíly mezi změnami rheologického chování roztoku polystyrenu při oscilačním smyku s vysokou amplitudou (LAOS) vyvolanými nanočásticemi. Výsledky vedou k závěru, že vysoce-afinní OP-POSS nanočástice při nízkých koncentracích dobře interagují s PS a tvoří tuhé agregáty, zatímco nízko-afinní OM-POSS nanočástice za těchto podmínek neovlivňují deformační chování polymerních řetězců. Dále byla pozornost zaměřena na vliv použitého rozpouštědla na uspořádání nanočástic v SiO2/PMMA a SiO2/PS nanokompozitech, který je v literatuře prezentován jako parametr řídící prostorové uspořádání nanočástic v pevném stavu. Důraz byl kladen na kvalitativní rozdíly mezi „špatně dispergovanými“ shluky nanočástic, které byly na základě rheologie a strukturální analýzy (TEM, USAXS) identifikovány jako polymerními řetězci vázané nanočásticové klastry a dva typy agregátů, jeden termodynamického a druhý kinetického původu. Jednotlivé druhy agregátů se vyznačují odlišnými kinetikami vzniku a rozdílnými vlastnostmi jak mezi sebou, tak v porovnání s dispergovanými nanočásticemi. Pozorované typy disperze nanočástic byly kvantitativně posouzeny podle svých rheologických vlastností během roztokové přípravy, podle kterých byla vyhodnocena míra adsorpce polymeru na povrch nanočástic a atrakce ve vypuzeném objemu. Výsledky byly porovnány s teorií PRISM. Důležitost uspořádání nanočástic byla demonstrována na porovnání teplot skelných přechodů různých struktur při stejném chemickém složení.
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Nanoparticles of platinum metals in the environment
Berka, Michal ; Kučerík, Jiří (referee) ; Komendová, Renata (advisor)
Platinum nanoparticles, mainly released from automotive catalysts, pose a potential risk to the environment. The aim of this bachelor thesis is to investigate the effect of platinum nanoparticles on soil properties at different humidities. Specifically, how nanoparticles affect the stability of hydrogen bridges, the stability of aliphatic crystals, and water retention in soil. For the analysis of relations between platinum nanoparticles, water and soil, a method of thermal analysis was used, namely differential scanning calorimetry. The theoretical part is devoted to the general introduction to platinum metals and nanoparticles. And the preparation of nanoparticles, their characterization and their properties. The result of the experiments is that platinum nanoparticles affect the soil properties relatively significantly.
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The development of ultra-high strength (UHPC) and reactive powder (RPC) composites
Rundt, Lukáš ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
Bachelor’s thesis studies ultra-high strength concrete and reactive powder composites. In theoretical part there are researched and described properties of raw materials used for their production, mainly additions. Design methodology, processing and types of curing are also studied. Psychical mechanic and durability properties of fresh and hardened concrete are described. In practical part 4 mixtures were designed and prepared and their rheological properties, strengths after 7 and 90 days in case of UHPC and strengths after 7, 28 and 60 days in case of RPC were tested.
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Analysis of biological significant substances
Maděránková, Denisa ; Rychtárik, Milan (referee) ; Roleček, Jiří (advisor)
Selected methods of Raman spectroscopy, like surface-enhanced Raman spectroscopy and single molecule Raman spectroscopy, are described in this diploma work. The basis of two methods for numerical modelling of optical properties of micro- and nanoparticles are prefaced. The methods are Discrete Dipole Approximation and Finite Difference Time Domain. Micro- and nanoparticles are used in surface enhanced Raman spectroscopy and other nanospectroscopic methods. Further, the main instrumentation needed for Raman spectroscopy is described. The first part of experimental section of this work is numerical modelling of photonic nanojet that occures behind dielectric microparticles. This phenomenon leads to a new technique of confocal microscopy with Raman spectra measuring. The second experimental section contains results of Raman spectra measurement with beta-carotene and surface-enhanced Raman spectra of beta-carotene in silver-sol solution.
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Influence of PbO and CdO nanoparticles on particular physiological functions in mouse.
Svozilová, Eva ; Vrlíková, Lucie (referee) ; Večeřa, Zbyněk (advisor)
The aim of this bachelor´s thesis is to assess the long-term effects of inhalation of nanoparticles of lead oxide and cadmium oxide on the weight of selected organs of experimental white mice. The selected organs (spleen, liver, kidney, lungs, brain) were successively collected during a period of thirteen weeks. The effect of inhalation of both metal oxides was statistically evaluated. In both study groups of the experiment (PbO and CdO), the relation between organs weight and the length of inhalation and the relation between organs weight and inhalation of differing metal concentrations were evaluated, and results both of the study groups were compared to each other.
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Surface Plasmon Resonances on Colloidal Nanoparticles
Beránek, Jiří ; Brzobohatý,, Oto (referee) ; Šikola, Tomáš (advisor)
The presented diploma thesis is focused on the Localized Surface Plasmons (LSP). The far-field optical response of the colloidal solutions of gold nanoparticles caused by LSP was investigated and compared with the numerical calculations. For the simulations, the Discrete Dipole Approximation (DDA) and Finite-Difference Time Domain (FDTD) techniques were employed. In particular, the shape and size effects of spherical particles and nanorods were studied. The simulations performed by both methods are in a good agreement for the spheres. For the nanorods, the resonance was found to be affected markedly by their geometry. Also, broader resonance peaks were found. This effect was assigned to the sample size distribution and its influence is discussed by comparing the simulations with experiments. In addition, synthesis of nanorods was carried out as well. Finally, the results on the study of optical properties of silver clusters formed under equilibrium conditions are presented.
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