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Plasma methods for modification and preparation of biopolymers
Červenková, Veronika ; Nikitin, Daniil (advisor) ; Kolská, Zdeňka (referee)
The thesis covers the main results of research on atmospheric pressure plasma modi- fication of biopolymers for the preparation of functional materials. Sodium alginate solu- tions processed by means of a plasma jet were successfully used for the casting of foils with advanced mechanical properties. It was observed that alginate's final performance does not only depend on the originating biopolymer viscosity but is significantly influenced by the type of working gas used for plasma modification. The antibacterial effect of alginate foils incorporated with almond essential oil was demonstrated as a promising extension of alginate's application in food storage. The results of plasma-initiated degradation of high-molecular-weight chitosan were studied in terms of its water-solubility. The analysis of structural properties demonstrated deep destruction of chitosan including the fragmen- tation of low-molecular-weight oligomers presented in the control sample. The fraction perfectly soluble in water was obtained using plasma processing as was demonstrated by NMR. The plasma solution system was demonstrated to be a suitable tool for enhancing chitosan's degradation for a possible application in crop protection. 1
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The Influence of Surface Treatment and Activation of Thin Film Composite Membranes with Plasma Discharge and Determination of Their Physicochemical Properties.
Slepička, P. ; Setničková, Kateřina ; Petrusová, Zuzana ; Slepičková-Kasálková, N. ; Kolská, Z. ; Siegel, J. ; Jansen, J. C. ; Esposito, E. ; Fuoco, A. ; Švorčík, V. ; Izák, Pavel
In this work we have focused on the surface treatment and activation of membranes (73 AC and 82 V) with plasma discharge and determination of their physicochemical properties. The surface morphology, wettability, zeta potential of pristine and plasma- treated membranes were tested and compared.
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Tuning the Photophysical Properties of Anti-B18H22 [1]
Braborec, Jakub ; Černá, H. ; Benkocká, M. ; Kolská, Z. ; Londesborough, Michael Geoffrey Stephen
The tuning of the photophysical properties of the highly fluorescent boron hydride cluster anti-B18H22 (1), by straight-forward chemical substitution to produce 4,4'-(HS)(2)-anti-B18H20 (2), facilitates intersystem crossing from excited singlet states to a triplet manifold.[1] This subsequently enhances O-2((1)Delta(g)) singlet oxygen production from a quantum yield of Phi(Delta) similar to 0.008 in 1 to 0.59 in 2. This contribution describes the synthesis and full structural characterization of the new compound 4,4'-(HS) 2-anti-B18H20 (2) and uses UV-vis spectroscopy coupled with DFT and ab initio computational studies to delineate and explain its photophysical properties. Additionally, we will report on new fluorescent derivatives of anti-B18H22 and their immobilisation on solid nanostructured substrates.
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