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Homogenity of aditives in nanofibres
Linha, Vojtěch ; Pokorný,, Marek (referee) ; Knotková,, Kateřina (advisor)
The goal of this thesis was to summarize basic options of fiber spinning and incorporation of additives. Options for nanofiber production by 4SPIN® are described along with particular electrodes for spinning in theoretical part. The experimental part was focused on influence of molecular structure of additives to incorporated volume of the substance. For this research four dye was used: erythrosine, riboflavin, briliant blue and eriochrom black. UV-Vis spectroscopy was used for evaluation of volume of aditives in nanofiber layer.
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Preparation and application of PHA based nanofibres and nanoparticles
Linha, Vojtěch ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The goal of this thesis was to summarize basic options of fiber spinning and manufacturing and their usability in industry. Methods of nanofiber spinning are described in the teoretical part, alongside the materials used in experimental part. The experimental part was focused on creating of workflow of defined nanofibers in laboratory enviroment, the possible modification of nanofibers with aditives. The release of aditives from different nanofibers into different enviroments was measured.
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Nanofiber membranes generating singlet oxygen with magnetic separation
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polyurethane nanofiber membrane with encapsulated 5,10,15,20-meso-tetraphenylporphyrin (TPP) photosensitizer and maghemite nanoparticles. The membrane was prepared by electrospinning and shows effective photogeneration of O2 (1 Δg) and photoantibacterial effect on the surface. The membrane can be easily separated by a magnetic field. The magnetic behaviour of the maghemite nanoparticles was studied using Mössbauer spectroscopy. Their size was estimated by DLS. The final nanofiber membrane was characterized by UV-VIS, emission spectroscopy, and by electronic microscopy (SEM). The kinetics of O2 (1 Δg) generation was studied by time-resolved spectroscopy and the relative efficiency of photooxidation was studied using external acceptor of O2 (1 Δg). Significant photoantibacterial properties against bacteria strain Escherichia coli were detected on the surface of the membrane functionalized with TPP photosensitizer.
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Photoctive Nanofiber Membranes for Oxygen Sensing
Ludačka, Pavel ; Mosinger, Jiří (advisor) ; Lang, Kamil (referee)
In this work, luminescent oxygen sensors based on the quenching of porphyrin sensor molecules encapsulated in a nanofibrous polymer matrix prepared by electrospinning were prepared and studied. The prepared sensors were characterized using electron microscopy, absorption and emission spectra, including time-resolved emission spectra. The sensitivity of the sensors was optimized in different polymer matrices, concentrations of porphyrin sensor molecules, and the thickness of the nanofibrous sensor layer. Furthermore, the photogeneration of singlet oxygen and the resulting antibacterial properties of the sensor nanofiber membrane were demonstrated. Key words Photoactive, nanofiber, oxygen, singlet oxygen, optical sensor
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Nanofiber membranes generating singlet oxygen with magnetic separation
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polyurethane nanofiber membrane with encapsulated 5,10,15,20-meso-tetraphenylporphyrin (TPP) photosensitizer and maghemite nanoparticles. The membrane was prepared by electrospinning and shows effective photogeneration of O2 (1 Δg) and photoantibacterial effect on the surface. The membrane can be easily separated by a magnetic field. The magnetic behaviour of the maghemite nanoparticles was studied using Mössbauer spectroscopy. Their size was estimated by DLS. The final nanofiber membrane was characterized by UV-VIS, emission spectroscopy, and by electronic microscopy (SEM). The kinetics of O2 (1 Δg) generation was studied by time-resolved spectroscopy and the relative efficiency of photooxidation was studied using external acceptor of O2 (1 Δg). Significant photoantibacterial properties against bacteria strain Escherichia coli were detected on the surface of the membrane functionalized with TPP photosensitizer.
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Preparation and application of PHA based nanofibres and nanoparticles
Linha, Vojtěch ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The goal of this thesis was to summarize basic options of fiber spinning and manufacturing and their usability in industry. Methods of nanofiber spinning are described in the teoretical part, alongside the materials used in experimental part. The experimental part was focused on creating of workflow of defined nanofibers in laboratory enviroment, the possible modification of nanofibers with aditives. The release of aditives from different nanofibers into different enviroments was measured.
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The role of sonication of PEO solutions with magnetic nanoparticles on morphology of the resulting nanofibrous mats
Peer, Petra ; Stěnička, M. ; Filip, Petr ; Pizúrová, Naděžda ; Babayan, V.
Properties of the resulting polymer nanofibres are often tailored by sonication technique applied prior or past an electrospinning process. The aim of this contribution is to evaluate morphology of nanofibrous mats formed by poly(ethylene oxide) with distributed magnetic nanoparticles (about 20nm in diameter) in dependence on time of sonication of the used polymer solutions. The solutions were exposed to sonication (intensity 200W, frequency 24 kHz) for 10, 30, and 60 minutes. It was shown that rheological characteristics (viscosity, storage and loss moduli) strongly depend on time of sonication (particularly phase angle) in contrast to electric conductivity and surface tension. For analysis of homogeneous distribution of magnetic field and magnetorheological efficiency (a relation of corresponding ciscosities) was process of electrospinning and resulting wuality of the obtained nanofibrous mats.
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Homogenity of aditives in nanofibres
Linha, Vojtěch ; Pokorný,, Marek (referee) ; Knotková,, Kateřina (advisor)
The goal of this thesis was to summarize basic options of fiber spinning and incorporation of additives. Options for nanofiber production by 4SPIN® are described along with particular electrodes for spinning in theoretical part. The experimental part was focused on influence of molecular structure of additives to incorporated volume of the substance. For this research four dye was used: erythrosine, riboflavin, briliant blue and eriochrom black. UV-Vis spectroscopy was used for evaluation of volume of aditives in nanofiber layer.
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Effect of Morphology of Nanostructures to Filter Ultrafine Particles
Kimmer, D. ; Vincent, I. ; Fenyk, J. ; Petráš, D. ; Zatloukal, M. ; Sambaer, W. ; Ždímal, Vladimír
Selected procedures permitting to prepare homogeneous nanofibre structures of the desired morphology by employing a suitable combination of variables during the electrospinning process are presented. A comparison (at the same pressure drop) was made of filtration capabilities of planar polyurethane nanostructures formed exclusively by nanofibres and space nanostructures having bead spacers or structures formed by a combination of micro-and nanofibres, through which ultrafine particles of ammonium sulphate 20 - 400 nm in size were filtered. The structures studied were described using a new digital image analysis technique based on black and white images obtained by scanning electron microscopy.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22013111915280 - PDF
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