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Analysis of the Hydrated ions Clusters Impact on the Liquid/Liquid Interface
Mareček, Vladimír; Samec, Zdeněk; Trojánek, Antonín
2022 - English
Open circuit potential (OCP) measurements of the partition of tetrapentylammonium chloride (TPeACl) at the water/1,2-dichloroethane (DCE) interface reveal two remarkable processes. The first one is characterized by a decay of the OCP from its expected equilibrium value. This process has been ascribed to the extraction of the salt driven by its accumulation in the hydrated salt clusters in the DCE phase. The second process is characterized by the short-term potential spikes overlapping the long-term OCP records. These spikes are assumed to be associated with the collision and fusion of the hydrated salt clusters produced by the former process with the water/DCE interface.
Keywords:
Water/1,2-dichloroethane interface; Salt partition; Open circuit potential
Available on request at various institutes of the ASCR
Analysis of the Hydrated ions Clusters Impact on the Liquid/Liquid Interface
Open circuit potential (OCP) measurements of the partition of tetrapentylammonium chloride (TPeACl) at the water/1,2-dichloroethane (DCE) interface reveal two remarkable processes. The first one is ...
Manufacture of 3D Printed Microfluidic Channels and Their Characterization by Impedance Spectroscopy and Optical Microscopy Measurements
Štěrba, O.; Vaněčková, Eva; Choińska-Mlynarczyk, Marta; Navrátil, Tomáš; Kolivoška, Viliam
2022 - English
Fused deposition modeling 3D printing employing high-resolution extrusion nozzles and specialized manufacturing protocols have recently attracted attention as an inexpensive tool to create microfluidic devices. In this work, we have applied such an approach to create measurement cells with integrated microchannels of systematically varied dimensions. The real width of channels was inspected by two techniques, namely (A) impedance spectroscopy employing an aqueous sensing electrolyte and (B) optical microscopic imaging of silicone imprints hardened in the interior of printed structures. Both techniques have demonstrated that fused deposition modeling 3D printing enables precise manufacturing of channels with truly microfluidic dimensions.
Keywords:
Fused deposition modeling 3D printing; Lab-on-a-chip devices; Microfluidic channels; Impedance spectroscopy; Optical microscopy
Available on request at various institutes of the ASCR
Manufacture of 3D Printed Microfluidic Channels and Their Characterization by Impedance Spectroscopy and Optical Microscopy Measurements
Fused deposition modeling 3D printing employing high-resolution extrusion nozzles and specialized manufacturing protocols have recently attracted attention as an inexpensive tool to create ...
Mercury Film Screen-Printed Electrodes
Josypčuk, Bohdan; Šestáková, Ivana; Tvorynska, Sofiia
2022 - English
Mercury film screen-printed electrodes (MF-SPEs) were designed, prepared and tested for the first time as perspective representatives among SPEs that allow measuring at high negative potentials. For this purpose, the precise electrochemical (coulometric) preparation procedure for mercury deposition at the working electrode surface of the commercial silver-SPE was developed and a universal method of preparing MF-electrodes from different metal-SPEs was described. An optimal electrolyzer construction for the mercury deposition, electrolyte composition, electrolysis potential, and an activation of electrode surfaces were proposed. Determination of the zinc content in food supplement tablets was used for the MF-SPEs practical testing.
Keywords:
flow analysis; mercury film; screen-printed electrodes; electrochemistry
Available on request at various institutes of the ASCR
Mercury Film Screen-Printed Electrodes
Mercury film screen-printed electrodes (MF-SPEs) were designed, prepared and tested for the first time as perspective representatives among SPEs that allow measuring at high negative potentials. For ...
Spectroelectrochemistry of 1,10-phenantrolines Substituted by Pyrrolidine and Phenothiazine Redox-active Units
Sokolová, Romana; Wantulok, J.; Fiedler, Jan; Nycz, J.; Degano, I.
2022 - English
Compounds based on 1,10-phenanthroline (Phen) and their complexes are used in many fields, such as a stabilizing agent in the synthesis of nanoparticles, catalysts in homogeneous catalysis and as a semiconductor in organic light-emitting diodes (OLED) due to their coordination abilities. In this work, 1,10-phenanthrolines functionalized by pyrrolidine and phenothiazine units were studied by electrochemical methods. Cyclic voltammetry resulted in several oxidation and reduction voltammetric peaks. Structure-activity relationship was investigated using in situ spectroeletrochemistry, spectrophotometry, infrared spectroscopy and chromatography.
Keywords:
1,10-phenanthroline; Electrochemistry; Oxidation mechanism; Reduction mechanism
Available on request at various institutes of the ASCR
Spectroelectrochemistry of 1,10-phenantrolines Substituted by Pyrrolidine and Phenothiazine Redox-active Units
Compounds based on 1,10-phenanthroline (Phen) and their complexes are used in many fields, such as a stabilizing agent in the synthesis of nanoparticles, catalysts in homogeneous catalysis and as a ...
Looking into the Photo-stability of Eosin by Electrochemical Methods
Sabatini, F.; Sokolová, Romana; Degano, I.
2021 - English
Eosin Y is a synthetic organic dye belonging to the xanthene family. Its bright and fluorescent\npink hue attracted and intrigued the painters of the 19th century, who experimented eosin as\npigment lake (often called Geranium lake) in their paintings. Nevertheless, eosin coloration is\nas beautiful as unstable, and examples of work of arts with faded hues have been documented.\nEosin is not only photo-sensitive but also pH sensitive, making its study very complex. In this\nwork, the combination of electrochemical and spectroscopic techniques revealed to be effective\nfor correlating the physical evidence of eosin fading with its chemical degradation.
Keywords:
Eosin; Synthetic dye; UV-Vis spectroelectrochemistry
Available on request at various institutes of the ASCR
Looking into the Photo-stability of Eosin by Electrochemical Methods
Eosin Y is a synthetic organic dye belonging to the xanthene family. Its bright and fluorescent\npink hue attracted and intrigued the painters of the 19th century, who experimented eosin as\npigment ...
Oxidation Processes of N-methylguanines
Trnková, L.; Třísková, I.; Liška, Alan; Ludvík, Jiří
2021 - English
The oxidation processes of N-methylguanines were investigated in both experimental and\ntheoretical way. Voltammetric oxidation potentials of guanine and its methyl analogues,\nacquired on polymer pencil graphite electrode (pPeGE), were compared with the HOMO\n(SOMO) energies calculated by density functional (DFT) methods. Our study contributes to\nunderstanding not only the oxidation processes of methylated guanines but also their role in\nepigenetics.
Keywords:
Guanine; N-methylated guanine; Oxidation process
Available on request at various institutes of the ASCR
Oxidation Processes of N-methylguanines
The oxidation processes of N-methylguanines were investigated in both experimental and\ntheoretical way. Voltammetric oxidation potentials of guanine and its methyl analogues,\nacquired on polymer ...
3D printed materials for the electrochemical determination of biologically active compounds
Choińska, Marta Katarzyna; Navrátil, Tomáš; Hrdlička, Vojtěch
2021 - English
3D printing materials are relatively novel materials in electrochemistry,\nused for manufacturing of electrochemical cells, electrodes\netc. They have been widely used mainly for tailored, fast, inexpensive,\nand easy preparation of various equipment for analyses of\nbiologically active compounds. Various medicinal products and illicit\ndrugs belong to this broad group of analytes which need to be\nmonitored because of the possibility of (un)intentional overdose or\nrecreational consumption, which can cause serious side effects or\neven death. Due to this risk, we decided to focus our research on the\ndevelopment of new, sensitive, selective, and easily customizable 3D\nprinted sensors for the determination of some commonly used\nantidepressants, analgesics, and illicit drugs.
Keywords:
analgesics; antidepressants; voltammetric determination
Available on request at various institutes of the ASCR
3D printed materials for the electrochemical determination of biologically active compounds
3D printing materials are relatively novel materials in electrochemistry,\nused for manufacturing of electrochemical cells, electrodes\netc. They have been widely used mainly for tailored, fast, ...
Preparation, Testing and Application of Amalgam Screen-Printed Electrodes
Josypčuk, Bohdan; Langmaier, Jan; Tvorynska, Sofiia
2021 - English
Silver amalgam screen-printed electrodes (AgA-SPEs) were designed, prepared, and tested for\nthe first time as perspective representatives among SPEs for measuring at high negative\npotentials. The precise coulometric preparation procedure for mercury deposition at the\nworking electrode surface of the commercial silver-SPE was developed. An optimal\nelectrolyzer construction for the mercury deposition, electrolyte composition, and electrolysis\nconditions were proposed. The maximum value of hydrogen overvoltage (-1979 ± 4 mV) was\nfound on AgA-SPE with 50% (w/w) of Hg content in 0.1 mol L-1 NaOH, which is more negative\nthan with the original silver-SPE for 387 mV (-1592 ± 12 mV).
Keywords:
electrochemistry; screen-printed electrodes; silver amalgam
Available on request at various institutes of the ASCR
Preparation, Testing and Application of Amalgam Screen-Printed Electrodes
Silver amalgam screen-printed electrodes (AgA-SPEs) were designed, prepared, and tested for\nthe first time as perspective representatives among SPEs for measuring at high negative\npotentials. The ...
Electrochemistry of Phospholes
Koláčná, Lucie; Liška, Alan; Ludvík, Jiří
2021 - English
Seventeen pentasubstituted phospholes with expected application in organic electronics were\nsynthesized and characterized electrochemically and by UV-vis spectra. Quantum chemical\ncalculations ofredox potentials and HOMO-LUMO energies were performed and experimental\nand theoretical data were successfully correlated. Tuning of redox properties can be achieved\nby combination of induction and resonance effects of substituents, extension / diminution of\nthe pi- delocalized system and by steric changes which affect intramolecular electron\ncommunication.
Keywords:
Pentasubstituted phospholes; Electrochemistry; UV-vis spectra
Available on request at various institutes of the ASCR
Electrochemistry of Phospholes
Seventeen pentasubstituted phospholes with expected application in organic electronics were\nsynthesized and characterized electrochemically and by UV-vis spectra. Quantum chemical\ncalculations ...
Electrochemical Characterization of Molecular Conductors Containing Redox Switching Element
Nováková Lachmanová, Štěpánka; Vavrek, František; Sebechlebská, Táňa; Šebera, Jakub; Kolivoška, Viliam; Lukášek, J.; Balzer, N.; Valášek, M.; Mayor, M.; Hromadová, Magdaléna
2021 - English
Electrochemical properties of new molecules containing tripodal anchor and redox switching\nelement have been studied by cyclic voltammetry and DFT quantum mechanical calculations.\nComparison of their redox properties with individual organometallic [Ru(terpy)2]2+t3+ and\n[Os(terpy)2]2+t3+ redox centers shows that covalently bonded tripodal anchor does not\ncompromise the reversibility of a redox process and has no effect on the stability of new\nmolecules. New molecular conductors have smaller HOMO-LUMO gap and both are oxidized\nat only slightly more positive potentials after tripodal substitution making them suitable for the\ndevelopment of molecular conductors with switching abilities.
Keywords:
Tripodal anchor; Cyclic voltammetry; DFT calculations
Available on request at various institutes of the ASCR
Electrochemical Characterization of Molecular Conductors Containing Redox Switching Element
Electrochemical properties of new molecules containing tripodal anchor and redox switching\nelement have been studied by cyclic voltammetry and DFT quantum mechanical calculations.\nComparison of ...
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