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Characterization of PVDF material in nanoscale resolution
Pisarenko, Tatiana ; Dallaev, Rashid (referee) ; Sobola, Dinara (advisor)
Tato práce se zabývá charakterizací nanovláken na bázi polyvinylidenfluoridu. Zaměření práce je na piezoelektrické vlastnosti vlákna, které jsou studovány metodou piezoelektrické silové mikroskopie. Takto byly měřeny dva typy odlišných vzorků, které se lišily v parametrech výroby. Odlišnosti vláken v jejich fázovém složení byly také zkoumány za využití Ramanovy spektroskopie a infračervené spektroskopie s Fourierovou transformací. Chemická analýza povrchu a jeho stavu proběhla pomocí rentgenové fotoelektronové spektroskopie. Různé uspořádání nanovláken spolu s jejich průřezem bylo pozorováno rastrovacím elektronovým mikroskopem za využití fokusovaného iontového svazku. Rovněž byla zkoumána smáčivost a kontaktní úhel povrchu vzorků s demineralizovanou vodou. Bylo zjištěno, že vyšší rychlost otáček válce během procesu elektrostatického zvlákňování má velmi významný vliv na jejich uspořádání a tím i na parametry ovlivňující tvorbu piezoelektrického jevu a dalších materiálových vlastností.
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Nanofiber materials simultaneously photogenerating NO and 1O2 species; Reversible NO binding on boron-containing clusters
Dolanský, Jiří
This project is concerned with the preparation of electrospun polystyrene (PS) nanofiber materials with covalently bonded NO-photodonor and electrostatically attached tetracationic porphyrinoid photosensitizers. These photofunctional nanofiber materials exhibit effective simultaneous photogeneration of small antibacterial NO and O2(1 ∆g) species under irradiation with daylight creating an antibacterial surface and near surrounding. NO species can be also generated just by gentle heating. Nanofiber materials were analyzed with SEM, FTIR, emission and UV/vis spectroscopy and time-resolved emission and absorption spetroscopy. The antibacterial effect was tested on Escherichia coli. The dual antibacterial action, in combination with the nanoporous character of the material that detains pathogens like bacteria on its surface, is ideal for any application where a sterile environment is neces- sary. The known bimetallic cluster system [(PMe2Ph)4Pt2B10H10] that possesses the propen- sity to reversibly bind small gaseous molecules (O2, SO2, CO) was synthesized in good yields for NO reversible binding investigation. Seven new monometallic precursors (Pt, Pd and Ni) to new bimetallic species were succesfully synthesized with the aim of future study of NO reversible binding. All new compounds were purified by...
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Preparation and characterization of nanostructured resorbable substitutes for accelerated skin healing
Kacvinská, Katarína ; Muchová, Johana (referee) ; Vojtová, Lucy (advisor)
Spolu s narastajúcimi nárokmi na kvalitu liečby v oblasti popálenin a plastickej chirurgie existuje možnosť ako uplatniť nové technologické riešenie na liečbu porúch s celkovou stratou kožnej vrstvy. Diplomová práca sa zaoberá prípravou nanoštrukturovaného, dvojvrstvového skafoldu pre využitie v tkánivovom inžinierstve, ktorý nahrádza kožnú časť dermis (dolná porézna vrstva) a bazálnu membránu (horná a tenká nanovlákenná vrstva). Zákaldom dolnej pórovitej vrstvy je kolagén, charakterizovaný v prítomnosti ďalších polysacharidových aditív: chitosan, vápenatá soľ oxidovanej celulózy (CaOC), sodná soľ karboxymetylcelulózy (NaCMC). Zároveň prídavok dopamínu a fibroblastového rastového faktoru (FGF), s cieľom zlepšiť biomechanické vlastnosti, regulovať a podporovať hojenie kože. Tenká nanovlákenná vrstva je zložená zo želatíny, polycaprolaktónu (PCL) a CaOC. Sú navrhnuté dva rôzne mechnizmy prípravy skafoldu, ktoré sa odlišujú sa v prítomnosti sieťovaných a nesieťovaných nanovláken. Skafoldy boli charakterizované z hľadiska biomechanických, štruktúrnych vlastností a in vitro. Vrchná nanovlákenná vrstva poskytuje mechanickú podporu, ktorá je výrazne zvýšená prítomnosťou polydopamínu (PDA). Test botnania poréznej vrstvy skafoldu ukázal na dostatočne veľké póry, umožňujúce filtráciu buniek. Táto botnatosť bola znížená v prítomnosti PDA, ktorý má zároveň významný vplyv na časové predĺženie degrádácie v prítomnosti kolagenázy a lyzozýmu. Spolu s FGF výrazne podporil proliferizáciu a životaschopnosť myších fibroblastov. Nanoštrukturovaný, dvojvrstvový skafold má potenciál pre budúce aplikácie pri hojení rán, kedže sa vyznačuje dobrými mechanickými vlastnosťami a umožňuje bunkám adherovať, proliferovať a formovať extra celulárny matrix.
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PREPARATION AND CHARACTERIZATION OF BIOPOLYMER-BASED NANOPARTICLES AND NANOFIBERS AND THEIR APPLICATION IN FOOD AND COSMETICS
Kundrát, Vojtěch ; Vilčáková, Jarmila (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
The presented dissertation thesis deals with the polymer polyhydroxybutyrate and other biopolymers as a basic building block for the construction of micro- and nanoscopic structures and materials used in food and cosmetics. In the theoretical part, current literary review is prepared to introduce the basics of this application field. The practical part of the work is composed of three blocks developed during the doctoral study. In the first and most important part are summarized comments to the academic and patent outputs, where among the academic ones it is possible to find two peer-reviewed articles dealing with the electrostatic and wet spinning of PHB and properties of prepared materials. The patent outputs consist of several accepted and applied projects, which summarize results on both PHB spinning methods, but also on general approaches enabling the processing of PHB into forms enabling many applications in food and cosmetics. Second part was focused on the patented composition of the UV protection cream based on the prepared nanoscopic and micro- morphologies of PHB. The third block summarizes results focused predominantly on the electrostatic spinning of PHB and other biopolymers. Finally, a short chapter containing a brief description of projects that were in a way related to the dissertation topic, but rather practical development work in Central Tanzania and West Africa, which draw on knowledge and contacts gained during studies at FCH BUT Brno.
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Flexible generators of electrical energy
Tesařová, Tereza ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This bachelor thesis is focused on actual research part of energy harvesting technologies – flexible electrical generators, which mean the special generating of electricity using specific flexible materials. The net charge result is affected by the incidental mechanism to transform certain energy form into electrical power and is influenced of material range, which determines what will be harnessed as a source of energy. The energy harvesting is aiming at producing alternative and efficient ways instead of harmful and strained manufacture processing.
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Posouzení životního cyklu produkce nanocelulózy ze dřeva : případová studie pro Českou republiku
Pajdla, Marek
This diploma thesis focuses on understanding the nanocellulose and production routes of this nano-scale cellulosic material. In the literature review, there is an overview of different production routes including pretreatment and treatment processes of biomass fibers and list of main global producers of nanocellulose currently available on the market. The practical part includes collected cost inputs for four different production scenarios which are: (1) enzymatic pretreatment with microfluidization treatment, (2) carboxymethylation pretreatment with microfluidization treatment, (3) enzymatic pretreatment with high-pressure homogenization treatment and (4) carboxymethylation pretreatment with high-pressure homogenization treatment. Costs of these four production routes are compared for three locations in the Czech Republic and contrasted with the cost of purchase of nanocellulose from abroad.
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Development of PVDF nanofibers sensor
Klásek, Matyáš ; Tofel, Pavel (referee) ; Hadaš, Zdeněk (advisor)
This diploma thesis deals with the feasibility of using PVDF nanofibers as an active sensor layer generating electrical signal. PVDF and related electromechanical effects are described. A research study is conducted regarding existing PVDF nanofiber applications and based on it, an event sensor design utilizing triboelectric effect and electrostatic induction is proposed. The electrical response of the layers is experimentally investigated and a pulse detection algorithm is conceived and implemented. Finally, a way of integrating the sensor into a rail track is proposed.
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Electrical characterization of flexible nanofiber piezoelectric materials
Pokorná, Romana ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This bacherol thesis is focused on piezoelectric nanofibrous materials. The first part describes the formation, use and possible aplications of nanofibers. It further analyze the principle of piezoelectric effect. It is a conversion of mechanical energy into electric energy and conversely. The second part is focused on design of experimental workplace for measurement of functional material properties. The last section of the thesis is dedicated to the electrical characterization of PVDF nanofibers and to the measurement of the piezoelectric charge constant.
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Functionalized chitosan-based nanofibres for accelerated regeneration of soft tissues
Bazikov, Philipp ; Filová, Eva (advisor) ; Kössl, Jan (referee)
To improve the regeneration of soft tissues, wound dressings were developed, containing nanofibers, different in composition and functional features. The work concentrates on chitosan and composite scaffolds containing chitosan. Porous nanofibre materials based on chitosan are very promising for the regeneration of soft tissues. Chitosan exhibits pH-sensitive behavior due to the large number of amino groups on its chains, which makes chitosan nanofibres promising carriers for the delivery of drugs. In this work, the examples of different modifications of nanofibres are shown. To increase the efficiency and accelerate the regeneration of soft tissues, nanofibres are functionalized with bioactive substances of various types: antimicrobial, analgesic, growth factors, etc. To stabilize nanofibres and to improve the physical characteristics, treatments using glutaraldehyde, glyoxal, genipin or heat treatment were used. Chitosan is used to inhibit fibroplasia during wound healing and to promote cell growth and differentiation. The efficiency of antibacterial activity of chitin-glucan complex with nanofibres for wound healing was shown. Reconstruction of deeper wounds, in which skin and soft tissues are damaged, requires measures for spatial reconstruction and stimulation of regeneration processes in the...
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Preparation, characterization and testing of blood derivatives for applications in regenerative medicine
Sovková, Věra ; Amler, Evžen (advisor) ; Kolářová, Hana (referee) ; Vránová, Jana (referee)
Platelet products can be used, thanks to the broad range of bioactive molecules, either as a supplement for cell cultering in vitro alone or for development of cell- or cell-free scaffolds in diverse fields in regenerative medicine. The aim of this study was to prepare several types of platelet products. The concentration of selected molecules were observed. Subsequently, these products were tested with cell cultures in vitro alone or in combination with nanofibres scaffolds prepared by electrospinning or centrifugal spinning. It was found out, that platelets products contains chemokine RANTES and growth factor PDGF in the highest concentrations. It was further discovered the content of pro and antiinflammatory in terleukins and other growth factors. Platelet lysat in concentration 7% is sufficient to replace FBS in keratinocytes and fibroblasts cultures. In the other experiments, platelets in different concentrations were adhered to the scaffolds prepared by electrospinning and centrifugal spinning. Thus prepared scaffolds promote the proliferation and viability of all tested cell types in dose-dependent manner. In the last experiment, the individual components of platelet concentrate were separated and characterized. Their effect to the cell culture were tested. It was examinated the synergic...
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