Wyszukiwarka
Filtry
wszystkich: 187
wybranych: 39
-
Katalog
Filtry wybranego katalogu
Wyniki wyszukiwania dla: membrane electrodes
-
Investigation of sour substances by a set of all-solid-state membrane electrodes
PublikacjaTestowano elektrody typu all solid state (ASS) w roztworach elektrolitów zawierających substancje o smaku kwaśnym. Elektrody typu ASS zawierają dwa typy membran. Badano wpływ grubości membrany oraz stosunku związek lipofilowy/ chlorek poliwinilu na odpowiedzi elektrod. Stwierdzono, że grubość elektro aktywnego polimeru, nie ma wpływu na czułość i stabilność elektrod w przeciwieństwie do grubości membrany składającej się ze związku...
-
Synthesis and application of tetrazole di and triamide derivatives in ion-selective membrane electrodes
PublikacjaA number of tetrazole diamides and triamides have been synthesized and applied as ion carries in ion-selective membrane electrodes. Their selectivity and sensitivity were studied towards alkali, alkaline earth, transition and heavy metal cations. it was found that membranes doped with 3 and 2-nitrophenyl octyl ether exhibit an almost theoretial Nernstian response for NH+ over relatively wide concentration range. Elestrodes with...
-
Inhibition of impurities formation in the synthesis of N-alkyltheobromines stimulated by microwave irradiation. Cationic and anionic response of membrane electrodes
PublikacjaN-Alkyltheobromine (1-9) derivatives were obtained by reacting theobromine with appropriate alkyl halide under microwave irradiation at 100-150 W and by conventional synthesis. Formation of by-products of oxygen atom alkylation and 1-N-alkyltheobromine ring opening were considered. The presented compounds 1-5 have been studied as ion carriers in ion-selective membrane electrodes. Selectivity of these membranes was studied towards...
-
Kinetic Description of the Membrane–Solution Interface for Ion-Selective Electrodes
Publikacja -
Plasticized PVC Membrane Modified Electrodes: Voltammetry of Highly Hydrophobic Compounds
Publikacja -
Dipodal Tetraamide Derivatives of 1,10-Diaza-18-Crown-6 and Alkylmalonic Acids—Synthesis and Use as Ionophores in Ion Selective Membrane Electrodes
PublikacjaNovel dipodal derivatives of an 18-membered diaza-crown ether with two diamide chains featuring methylmalonic or butylmalonic acid residues were obtained and tested as ionophores in ion-selective plasticized membrane electrodes. The objective of the study was to identify measurement conditions which ensure the most favorable performance for magnesium ion-selective electrodes. The relationship between the molar lipophilic anion...
-
Lower Rim Substituted tert-Butyl Calix[4]arenes (Part IV). Calix[4]arene-Crown Ethers as Ionophores in Plasticized PVC-membrane electrodes.
PublikacjaPrzedstawiono syntezę i charakterystykę trzech p-tert-butylokaliks[4]aren-koron-4, -5, -6 (związki 2 - 4 o różnej długości łańcucha polyoksaetylenowego łączącego distalne grupy OH). Syntezowane związki wykazują wysoką selektywność na kationy sodu, potasu lub cezu. Badano zależność pomiędzy stereochemiczną strukturą tych ligandów, a wyznaczonymi potencjometrycznie współczynnikami selektywności oraz wyznaczonymi stałymi trwałości...
-
Lower rim substituted tert-Butylcalix[4]arenes. Part 13. Interaction of calix-hydroxamates with Fe(III) and Pb(II); studies in ion-selective membrane electrodes (ISE)
PublikacjaPrzedmiotem pracy są badania oddziaływań pomiędzy trzema wybranymi hydroksamowymi pochodnymi t-butylo-kaliks[4]arenu i jonami metali z wykorzystaniem membranowych elektrod jonoselektywnych (ISE). Elektrody zawierające jako materiał aktywny wymienione związki jonoforowe charakteryzują się nernstowskim nachyleniem i szerokim zakresem liniowości na jony Pb(II), a także dobrą selektywnością na jony Pb(II)w stosunku do jonów UO2(II),...
-
Comparative Study of Taste Substance Sensing by Liquid Membrane Oscillator and Electrochemical Systems With All-Solid-State Electrodes
PublikacjaIn food industry, different types of sensors are used for characterizing and quantifying taste substances. Therefore, it is important to establish the principal advantages and disadvantages of these sensors for optimal application. In this paper, two possible systems are compared for sensing the four fundamental tastes: sour (citric acid), salty (sodium chloride), sweet (sucrose), and bitter (caffeine or quinine hydrochloride). One...
-
Lower rim substituted tert-butyl calix[4]arene (part VII): ionophoric properties of calix[4]arene-crown-6 derivatives in plasticized PVC-membrane electrodes and in solution.
PublikacjaW pracy przedstawiono syntezę i charakterystykę otrzymanych produktów (2-9), pochodnych p-tert-butylokaliks[4]-korony-6. Zdolności kompleksujące tych związków badano w elektrodach jonoselektywnych, stosując te związki jako jonofory w plastyfikowanej membranie PCW.Wyznaczono wartości stałych trwałości kompleksów z jonami metali I grupy. Stwierdzono, że selektywność kompleksowania zależy od rozmiaru i natury podstawnika wprowadzonego...
-
Lower Rim Substituted p-tert-Butyl Calix[4]arenes(V). Synthesis of New 5,11,17,22-tetrakis-p-tert-Butyl-25-27-bis(dialkoxyphosphorylmethoxy)calix[4] arenes and Cation Complexation Studies in Ion Selective Membrane Electrodes.
PublikacjaZaprezentowano syntezę i właściwości trzech nowych związków (2-4), bis podstawionych na dolnym obrzeżu grupami z resztą fosforylową. Związki te były badane jako jonofory w membranowych elektrodach jonoselektywnych (ISE) wykazując selektywność na kationy Rb+,K+ oraz duży i płaski kation guanidyniowyG+). Badano korelację pomiędzy stereo-strukturą związków a ich selektywnością w ISE. Stałe trwałości kompleksów z kationami metali...
-
INVESTIGATION OF ACIDIC SOLUTIONS BY POTENTIOMETRIC TASTE SENSOR WITH ALL SOLID STATE ELECTRODES
PublikacjaPotentiometric taste sensors with electrodes containing lipophilic compound / polymer membranes were already used to distinguish commercial liquid products. In this paper a new potentiometric taste sensor consisting of six All Solid State Electrodes (ASSEs) has been presented. Each of the membrane contains a selected lipophilic compound. The set-up consists of a reference electrode and six ASSEs. The inner layer made of a conducting...
-
Investigation of poly(3,4-ethylenedioxythiophene) deposition method influence on properties of ion-selective electrodes based on bis(benzo-15-crown-5) derivatives
PublikacjaGlassy carbon electrodes modified by conductive polymers and membrane with derivatives of bis(benzo-15-crown-5) were tested as solid contact ion selective electrodes for K+ ions concentration determination. PEDOT with PSS, Cl- and ClO4- counter ions was electrochemically deposited onto glassy carbon substrates using four different electrochemical approaches (potentiostatic, galvanostatic, potentiodynamic and potentiostatic pulses)....
-
Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) - synthesis and properties
PublikacjaDerivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu2+, Ni2+, Zn2+, Co2+, Fe2+ and Pb2+) was studied. Ligands 5-8 were additionally...
-
Synthesis and properties of new 'N,'N-phenyltetrazole podand
PublikacjaThe synthesis of a new chromogenic N,N-phenyltetrazole receptor is reported here. The cationbinding properties of this receptor in solution were investigated by naked-eye colour change, electrochemical methods and UV-Vis spectroscopy in various solvents (CH3CN, dimethylsulphoxide (DMSO), DMSO/H2O, CH3CN/H2O and CH3CN/MeOH). In addition, the receptor was used as a sensing material in ion-selective membrane electrodes. The selectivity...
-
Lower Rim Substituted p-tert-Butyl-Calix[4]arene. Part 16. Synthesis of 25, 26, 27, 28-tetrakis(piperidinethiocarbonylmethylene)-p-tert-butylcalix[4]arene and its interaction with metal ions
PublikacjaThe synthesis, characterisation and X-ray crystal structures of p-tert-butyl-calix[4]arenethioamide L and its complex with lead L-Pb2+ is reported. The cation-binding properties in solution have been assessed by liquid-liquid extraction of the metal picrates from water into dichloromethane and by stability constants determination in acetonitrile using UV-absorption spectrophotometry or potentiometry. The compound was used as active...
-
Calix[4]arenes appended with thioamide moieties as powerful tool for heavy metals recognition
PublikacjaSelectivity of new thioamide derivatives was assessed using those ligands as sensor materials in ion-selective membrane electrodes and tested towards Pb2+ - selectivity. The influence of the nature of the thioamide function (linear, branched or cyclic substituents) on their ionophoric properties was investigated. Electrodes based on cyclic thioamide moieties are promising analytical tools for monitoring Pb2+ concentration in natural...
-
New bis(azobenzocrown)s with dodecylmethylmalonyl linkers as ionophores for sodium selective potentiometric sensors
PublikacjaNovel biscrowns 1 and 2 were synthesized from 13-membered azobenzocrown ethers containing bromoalkylenoxy chains in para position relative to the azo group. The synthesized diester molecules are dodecylmethylmalonic acid derivatives differing by the linker length. The synthesized compounds have the potential of being used as sodium ionophores in ion-selective electrodes. They were characterized and used as ionophores in classic...
-
O-substituted tetrahydroxamate derivatives of p-tert-butylcalix[4]arene as receptors for transition and heavy metal cations
PublikacjaTetrasubstituted O-hydroxamate derivatives of p-tert-butylcalix[4]arene were applied as active materials in ion-selective membrane electrodes and were tested towards Pb-selectivity. The electrodes gave near-Nernstian characteristics for Pb2+ cations. The selectivity coefficients were determined. The influence of plasticizer on the electrode behaviour was studied. The dependence of the chemical structure on selectivity coefficients...
-
A prototype of electrochemical sensor for measurement of carbonyl compounds in air
PublikacjaThe paper presents the results of investigation on a prototype sensor for measurement of benzaldehyde and formaldehyde in air. Sensitivity, limit of quantification and coefficient of selectivity of the sensor have been determined as a function of membrane thickness and electrode type using square wave voltammetry (SWV) technique. The working and counter electrodes were made of platinum and gold. Ionic liquids 1-hexyl, 3-methylimidazolium...
-
Potentiometric sensor containing set of ion selective electrodes with lipid modified membranes for quality assessment of tested non-alcoholic beverages
PublikacjaPotentiometric sensors may be a good tool for fast quality control of commercial drinks. In this work, such a sensor, containing a set of ion-selective electrodes with lipid-modified membranes (benzylhexadecyldimethylammonium chloride monohydrate, hexadecylamine, 1-dodecanol, elaidic acid, cholesterol) was used for discrimination and quality control of non-alcoholic beverages, mainly composed of sugar and citric acid. It was found...
-
Selective detection of F- by chromogenic tetrazole receptor
PublikacjaA chromogenic anion host 4, containing two amide functionalities linked to azo dye and tetrazole rings was synthesized and its complexes with various anions were investigated. The results show that receptor 4 can recognize selectively biologically important F- ion. The binding affinity for F- was investigated by naked-eye colour change, UV-Vis and 1H NMR spectroscopy. Addition F- ion in CH3CN and DMSO to receptor 4 cause a colour...
-
All solid state electrodes taste sensor with modified polymer membranes for discrimination of mineral water with different CO2 content
PublikacjaA potentiometric taste sensor with All Solid State Electrodes containing five all solid state electrodes with appropriate lipophilic compounds (benzyldimethyltetradecylammonium chloride, dodecyltrimethylammonium bromide, palmitic acid, stearic acid, and phytol) embedded in a polymer membrane was applied for discrimination of mineral water samples differed in CO2 content. Samples of still, slightly sparkling, and sparkling Naleczowianka...
-
The possibility of the application of a potentiometric sensor with all-solid-state electrodes for the quality control of different natural waters
PublikacjaThe quality of various natural waters was examined by a new potentiometric sensor with six all solid state electrodes containing an appropriate lipophilic compound in a polymer membrane. Physicochemical parameters such as conductivity and acidity of tested waters were also tested. All waters were neutral or slightly alkaline and contained different ions (e.g., Cl–) due to the place of their sampling (a coastal zone and a moraine...
-
Lower rim substituted p-tert-butyl-calix[4]arene. Part 17. synthesis, extractive and ionophoric properties of p-tert-butylcalix[4]arene appended with hydroxamix acid moieties
PublikacjaThe synthesis and characterization of four p-tert-butylcalix[4]arene-hydroxamic acidc are reported. The dependence of the metal ion binding, assessed by liquid extraction of the metal nitrates from water into dichloromethane in individual and competitive experiments, on the ligand structure, is presented. The results showed that those ligands could be successfully used in separation process of trnasition and heavy metals often...
-
Investigation of sweet substances of different molecular structure by potentiometric taste sensor with all solid state electrodes
PublikacjaA five channel potentiometric taste sensor consisting of an array of All Solid State Electrodes (ASSESs) with different lipid-polymer membranes has been developed. The electrodes are constructed of glassy carbon discs with electrochemically deposited poly(3,4-ethylenedioxythiophene) (PEDOT) acting as ion to electron transducer. The outer layer of the electrode is lipid-polymer membrane. Lipid substances immobilized in PVC membranes...
-
Potentiometric Solid-Contact Multisensor System for Simultaneous Measurement of Several Ions
PublikacjaThe design and performance of potentiometric multisensor system made in solid-contact technology is described. Both, the measuring electrodes as well as the reference electrode are in a compact cell. The system allows for simultaneous measurement of various ions. The characteristics of the electrodes for Na+, K+ and Ca2+ ions were determined using the designed system and compared with ISEs of the same membrane composition in classical...
-
Electrochemical sensor for measurement of volatile organic compounds employing square wave perturbation voltage
PublikacjaThe paper presents the results of investigation on a prototype sensor for measurement of benzaldehyde in air. Sensitivity and limit of quantification of the sensor were determined for different internal electrolyte using the square wave voltammetry (SWV) as a detection technique. The working and counter electrodes were made of platinum. Ionic liquids 1-hexyl, 3-methylimidazolium chloride,1-hexyl, 3-methylimidazolium bis (trifluoromethanesulfonyl)...
-
Functionalized azobenzocrown ethers as sensor materials—The synthesis and ion binding properties
PublikacjaNew 13- and 16-membered azobenzocrown ethers with aromatic amino, amide, ether–ester or ether–amide residue in para position to an azo moiety were obtained. Acid–base properties and ion binding ability of the colored compounds were studied by spectroscopic methods: UV–vis, fluorimetry and 1H NMR spectroscopy. Selected azobenzocrowns were tested as ionophores in ion-selective membrane electrodes (ISEs) – classic and miniature all...
-
A miniaturized solid-contact potentiometric multisensor platform for determination of ionic profiles in human saliva
PublikacjaThis paper describes a miniaturized multisensor platform (MP-ISES) consisting of electrodes: a reference one (RE) and ion-selective electrodes (ISEs) for monitoring Na+, K+, Ca2+, Mg2+, Cl−, and SCN− ions and pH in human saliva. Gold electrode surface was modified by deposition of two layers: electrosynthesized PEDOT:PSS forming an intermediate layer, and ion-selective membrane. The developed ISEs were characterized by a wide linear...
-
Chromogenic macrocyclic derivatives of azoles - synthesis and properties,
PublikacjaNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
-
Azomacrocyclic derivatives of imidazole: synthesis, structure, and metal ion complexation properties
PublikacjaNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
-
Evolution of the nanostructure of Pt and Pt–Co polymer electrolyte membrane fuel cell electrocatalysts at successive degradation stages probed by X-ray photoemission
PublikacjaWe present a set of XPS (X-ray photoemission spectroscopy) measurements and detailed data-analysis of electrodes for polymer electrolyte membrane fuel cell (PEMFC) based on carbon supported catalysts (Pt and Pt–Co) subjected to a step-like potential cycling (accelerated degradation test). The results of the measurements complete and corroborate parallel TEM (transmission electron microscopy), XRD (X-ray diffraction) and XAS (X-ray...
-
Simple synthesis route for fabrication of protective photo‐crosslinked poly(zwitterionic) membranes for application in non‐enzymatic glucose sensing
PublikacjaThis work focuses on the fabrication of non-enzymatic glucose sensing materials based on laser-formed Au nanoparticles embedded in Ti-textured substrates. Those materials possess good catalytic activity toward glucose oxidation in 0.1 × phosphate buffered saline as well as resistance to some interferants, such as ascorbic acid, urea, and glycine. The electrodes are further coated with three different polymers, that is, Nafion,...
-
Potentiometric Solid-Contact Ion-Selective Electrode for Determination of Thiocyanate in Human Saliva
PublikacjaA new solid-contact potentiometric ion-selective electrode for the determination of SCN− (SCN-ISE) has been described. Synthesized phosphonium derivative of calix[4]arene was used as a charged ionophore. The research included selection of the ion-selective membrane composition, determination of the ISEs metrological parameters and SCN-ISE application for thiocyanate determination in human saliva. Preparation of the ISEs included...
-
A Flexible Nafion Coated Enzyme‐free Glucose Sensor Based on Au‐dimpled Ti Structures
PublikacjaThe detection of glucose at low concentrations using electrochemical sensors is of great importance due to the possibility of using different human body fluids than blood, such as e.g. urine, saliva, sweat or tears. The interest behind those biofluids is related to their utility in non-invasive sugar determination. In this work, we present flexible, fully biocompatible electrode material based on Au nanoparticles immobilized onto...
-
Enzymatic electrodes nanostructured with functionalized carbon nanotubes for biofuel cell applications
PublikacjaNanostructured bioelectrodes were designed and assembled into a biofuel cell with no separating membrane.
-
Synthesis, characterization, and interactions of single-walled carbon nanotubes modified with doxorubicin with Langmuir–Blodgett biomimetic membranes
PublikacjaThe synthesis, characterization, and the influence of single-walled carbon nanotubes (SWCNTs) modified with an anticancer drug doxorubicin (DOx) on the properties of model biological membrane as well as the comparison of the two modes of modification has been presented. The drug was covalently attached to the nanotubes either preferentially on the sides or at the ends of the nanotubes by the formation of hydrazone bond. The efficiency...
-
Elucidating charge transfer process and enhancing electrochemical performance of laser-induced graphene via surface engineering with sustainable hydrogel membranes: An electrochemist's perspective
PublikacjaLaser-induced graphene (LIG) has emerged as a promising solvent-free strategy for producing highly porous, 3D graphene structures, particularly for electrochemical applications. However, the unique character of LIG and hydrogel membrane (HM) coated LIG requires accounting for the specific conditions of its charge transfer process. This study investigates electron transfer kinetics and the electroactive surface area of LIG electrodes,...