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Investigation of mass changes by piezoelectric resonator
Kužílek, Jakub ; Svoboda, Vít (referee) ; Špičák, Petr (advisor)
An operation deals with a concept of the new cell for measuring weight changes with high precision through the use of quartz crystal micro-scales called QCM. The new cell is destined for crystal resonators which diameter is 14mm. The resonators are produced in the Czech Republic. A price is the greatest advantage of crystal resonators in comparison with original crystals. The next positive is higher mechanical tolerance which is outgoing of a guest-size. The cell designed by this way is tested in electrochemical system where a deposition of metallic copper in crystal is happening. A homologation of accuracy is judged by Faraday’s law and using Sauerbrey equation for quartz crystal microbalance in cyclic voltammetry measurement method.
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Construction of an electrochemical cell based on carbon film electrode
Libánský, Milan ; Zima, Jiří (advisor) ; Fischer, Jan (referee)
This Thesis deals with the construction of an electrochemical cell with two types of integrated composite electrodes based on carbon films. Using these electrodes, the voltammetric behavior of environmental pollutant triclosan (5-chlor-2-(2,4- dichlorophenoxy)phenol) was studied. For the construction of composite electrodes, graphite and glassy carbon were used as conductive microparticles. Several types of polymers served as the nonconductive binder. For the measurements, combinations of graphite with polystyrene and graphite with polycarbonate were selected as optimum materials. From the dependence of peak heights on solution composition, a mixture of a buffer of pH 7 and methanol (1:9, V/V) was selected as the optimum medium. In this medium, concentration dependences were measured; calculated triclosan detection limit were 0,49 µmol dm-3 for carbon polystyrene composite electrode and 0,25 µmol dm-3 for carbon polycarbonate composite electrode, respectively. The possibility of further increasing the sensitivity of the determination by the accumulation step was studied. Accumulation of triclosan on carbon polystyrene composite electrode was observed, but the increase in response was connected with the loss of repeatability. Accumulation of triclosan on carbon polycarbonate composite electrode was...
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Construction of an electrochemical cell based on carbon film electrode
Libánský, Milan ; Zima, Jiří (advisor) ; Fischer, Jan (referee)
This Thesis deals with the construction of an electrochemical cell with two types of integrated composite electrodes based on carbon films. Using these electrodes, the voltammetric behavior of environmental pollutant triclosan (5-chlor-2-(2,4- dichlorophenoxy)phenol) was studied. For the construction of composite electrodes, graphite and glassy carbon were used as conductive microparticles. Several types of polymers served as the nonconductive binder. For the measurements, combinations of graphite with polystyrene and graphite with polycarbonate were selected as optimum materials. From the dependence of peak heights on solution composition, a mixture of a buffer of pH 7 and methanol (1:9, V/V) was selected as the optimum medium. In this medium, concentration dependences were measured; calculated triclosan detection limit were 0,49 µmol dm-3 for carbon polystyrene composite electrode and 0,25 µmol dm-3 for carbon polycarbonate composite electrode, respectively. The possibility of further increasing the sensitivity of the determination by the accumulation step was studied. Accumulation of triclosan on carbon polystyrene composite electrode was observed, but the increase in response was connected with the loss of repeatability. Accumulation of triclosan on carbon polycarbonate composite electrode was...
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Investigation of mass changes by piezoelectric resonator
Kužílek, Jakub ; Svoboda, Vít (referee) ; Špičák, Petr (advisor)
An operation deals with a concept of the new cell for measuring weight changes with high precision through the use of quartz crystal micro-scales called QCM. The new cell is destined for crystal resonators which diameter is 14mm. The resonators are produced in the Czech Republic. A price is the greatest advantage of crystal resonators in comparison with original crystals. The next positive is higher mechanical tolerance which is outgoing of a guest-size. The cell designed by this way is tested in electrochemical system where a deposition of metallic copper in crystal is happening. A homologation of accuracy is judged by Faraday’s law and using Sauerbrey equation for quartz crystal microbalance in cyclic voltammetry measurement method.
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