Heterogeneous Chemiluminescence Research Articles

In English

The properties of heteropoly acids and of their complexes with cationic surfactants at the trace level have been studied by ESR spectroscopy, UV-VIS spectrophotometry, NMR and FTIR spectroscopy, by the method of chemiluminescence analysis applied in aqueous solutions and on the cellulose surface. For elucidation of the mechanism of chemiluminescence reactions of heteropoly acids with luminol kinetic methods, diffuse reflectance spectroscopy and liquid chromatography have been applied. For the first time one-electron reduction of heteropoly acids by luminol was confirmed by registration of diffuse reflectance spectra of reduced heteropoly acids on cellulose surface. It has been suggested that the mechanism of heteropoly acids immobilization on cellulose includes combination of Coulomb and hydrophobic interactions. A scheme of heteropoly acids immobilization on the surface was proposed based on ion exchange processes on cellulose or diethylaminoethyl cellulose surface. It has been shown that ionic associates heteropoly acid – cationic surfactant react with an alkaline solution of luminol with light emission similarly to heteropoly acids themselves. For the first time, heterogeneous chemiluminescence, namely, the chemiluminescence of heteropoly acids immobilized on cellulose, with luminol, has been used for examining the composition of ionic associates heteropoly acid - cationic surfactant. By using Bjerrum’s method it has been found that in strongly acidic media (at pH 1.0) vanadomolybdophosphoric acid forms with cationic surfactant, namely, with dodecylpyridinium bromide, not tetra-substituted but triply substituted ionic associate. This result can be explained by the fact that the fourth proton in H4PVMo11O40 is weakly dissociated; it is more strongly bound to heteropoly anion and is localized on the oxygen atom of the Mo–O–Mo angular bond. Ionic associates of heteropoly acids were used as analytical forms for highly sensitive chemiluminescence determination of P, As, Si, Ge in waters of different types. Detection limits for P, As, Si, Ge are 0.02–0.07 µg/L. Due to the high sensitivity of the method, phosphorus was successfully determined in surface water and ultrapure water, arsenic – in river and mineral water, silicon – in ultrapure water and vapor condensate of electric power stations, germanium – in water of electronic industry.

Fabric-based in situ synthesis of gold nanoparticles for continuous enhanced heterogeneous chemiluminescence online detection of carbon dioxide.

In this paper, nylon microfiber fabric with a heterogeneous chemiluminescence system was used for the synthesis of gold nanoparticles (AuNPs) for the first time, and it was used to enhance the online detection of carbon dioxide (CO2) by heterogeneous chemiluminescence. Nylon microfiber fabric was chosen as the gas-liquid heterogeneous chemiluminescence micro reaction interface. The thermal reduction method prepared the micro reaction interface with in situ synthesized AuNPs. The solution of H2O2 and KOH forms a liquid film on the surface of the micro reaction interface, and a heterogeneous chemiluminescence reaction occurs when CO2 flows through the surface of the liquid film. The AuNPs supported in situ on the micro reaction interface act catalytically and enhance the chemiluminescence signal for CO2 detection. In this way, AuNPs can be used repeatedly in the chemiluminescence reaction, avoiding the waste of precious metal nanoparticles and reducing the detection cost. Under the optimal conditions, CO2 has a good linear relationship with the chemiluminescence signal in the range of 10-20 000 ppm (v/v). The correlation coefficient R2 is 0.9963, the detection limit is 0.35 ppm (v/v), and the relative standard deviation is 1.79%. This approach provides an entirely new technological platform for the development of functional fabrics and the maximum utilization of precious metal nanoparticles.

An Apparatus for Studying Phosphor Luminescence upon Excitation by Atomic–Molecular Beams

The scheme, design, and hardware of a new laboratory apparatus for studying the interaction of beams of free atoms and molecules with the surfaces of phosphors are described. Methods for measuring the efficiency of electronic radiative processes on surfaces for studying the mechanisms of energy transfer and surface changes based on the spectral–kinetic characteristics of heterogeneous chemiluminescence are presented. Luminescent methods for studying the heterogeneous recombination of hydrogen atoms on the surfaces of solids allow one to explicitly select the impact (Rideal–Eley) and diffusion (Langmuir–Hinshelwood) recombination mechanisms and estimate the fraction of contributions of these mechanisms to the total recombination rate of atoms depending on the flow density of free atoms and the sample temperature. Examples of studying the spectra of the heterogeneous chemiluminescence (HCL) and photoluminescence (PL) at different temperatures of an AlN : Eu3+ phosphor under the excitation with hydrogen atoms and a mercury lamp are given. During processing of the kinetic curves of the HCL buildup and decay for ZnS : Tm3+ phosphor upon switching the Н + Н2 atomic–molecular beam on and off, an example of obtaining the parameters of atomic–molecular processes on the surface (adsorption, impact and diffusion recombination of atoms, and desorption of hydrogen molecules) is presented.

Non-stationary luminescent methods for studying the interaction of hydrogen atomic with ZnS:Tm3+ surface

The results of studying the interaction H atoms with ZnS–Tm3+ surface using the phenomena of heterogeneous chemiluminescence (HCL) are presented. HCL is luminescence excited in the strongly exothermic interaction acts of hydrogen atoms on the surface. The kinetic and nonstationary characteristics of luminescence are studied in depending on the excitation conditions, which serve as light indicators of physicochemical processes, occurring on the surface. The interaction parameters of hydrogen atoms with the surface of zinc sulphide: cross-sections, frequency factors, activation energies based on kinetic and non-stationary characteristics of HCL are determined.

РАЗВИТИЕ МЕТОДА ЛЮМИНЕСЦЕНТНОГО КОНТРОЛЯ СОСТАВА ПЛАЗМЫ И ОБРАБАТЫВАЕМОЙ ПОВЕРХНОСТИ В ТЕХНОЛОГИИ АНТИКОРРОЗИОННОЙ ЗАЩИТЫ НЕФТЕГАЗОВОГО ОБОРУДОВАНИЯ

Актуальность. Надежность и целостность нефтедобывающего оборудования, сроки его эксплуатации обеспечиваются комплексом мер по борьбе с коррозией, в частности использованием технологий газопламенного напыления защитных покрытий на проектируемые или восстанавливаемые детали. В данных технологиях эффективным методом контроля за состоянием состава плазмы и качества напыляемой поверхности может служить явление гетерогенной хемилюминесценции. Гетерогенные хемилюминесцентные реакции обладают селективностью и высокой чувствительностью к типу поверхности и сорту возбуждающего газа. Использование оптических методов для изучения, контроля и управления в неравновесных системах газ–твердое тело открывает новые аналитические и аппаратурные возможности в физике поверхности, химии, плазмохимии, технологии полупроводников и люминофоров, в решении экологических проблем. Изучение процессов адсорбции–десорбции, диссоциации, диффузии, рекомбинации газовых частиц, дефектообразования и роста кристаллической решетки с использованием явления гетерогенной хемилюминесценции является актуальной задачей физики конденсированного состояния. Поскольку явление гетерогенной хемилюминесценции реализует возможности осуществления селективных экспресс-методов анализа при простом аппаратурном оснащении с пределом обнаружения свободных атомов, радикалов, примесей в газовой фазе и в составе поверхностных слоев конденсированных сред до 10–6 % (мол). Цель: исследование процессов в неравновесных системах газ – твердое тело и определение параметров этого взаимодействия на основе регистрации характеристик гетерогенной хемилюминесценции; разработка нестационарных методов определения параметров взаимодействия газ–твердое тело с использованием явления гетерогенной хемилюминесценции, контроль параметров газовой среды и состояния поверхности конденсированных сред. Объекты: атомно-молекулярные пучки водорода, кристаллофосфор ZnS–Mn2+, приповерхностные области взаимодействия газ – твердое тело. Методы: методы, основанные на явлении гетерогенной хемилюминесценции в атомарном водороде для определения скоростей адсорбции и рекомбинации атомов Н, десорбции молекул H2, энергии активации десорбции молекул водорода с поверхности ZnS–Mn2+. Методом «темновой» паузы определена скорость рекомбинации адсорбированных атомов водорода по механизму Лэнгмюра–Хиншелвуда. Результаты. Выполнено сравнительное исследование люминесценции ZnS–Mn2+ при возбуждении светом (фотолюминесценции) и атомарным водородом (гетерогенной хемилюминесценции). Изучены спектрально-кинетические характеристики люминесценции. Установлены механизмы и параметры взаимодействия атомов водорода с поверхностью сульфида цинка (сечения, частотные факторы, энергии активации) с использованием спектрально-кинетических характеристик гетерогенной хемилюминесценции. Показано, что люминофор ZnS–Mn2+ может служить экспресс датчиком восстановительной компоненты плазмы (водород). Явление гетерогенной хемилюминесценции составляет основу оперативных методов контроля начальных стадий модификации поверхности твердых тел в процессах пучково-плазменной обработки материалов.

Heterogeneous Chemiluminescence from Gas-Solid Phase Interactions of Ozone with Alcohols, Phenols, and Saccharides.

Gas-solid phase reactions between ozone (O3) and three representative solids (alcohols, phenols, and saccharides) were investigated through a heterogeneous chemiluminescence (CL) strategy. When interactions between these two species occurred at the surface of the solid powder, an obvious CL effect was obtained. This performance could be attributed to the evolution of a ROOOH intermediate, which subsequently released emissive 1O2 species. This is the first report analyzing the gas-solid phase CL performance of O3 with alcohols, phenols, and saccharides. It is believed that this strategy can be extended to applications in other gas-solid phase CL analyses utilizing the O3 system. This has also created a novel area of gas-solid CL performance; thus, relevant processes and mechanisms can be deduced and identified.

On the heterogeneous chemiluminescence of Y2O2S crystal phosphors activated by europium

The results of studying the kinetic and spectral characteristics of the heterogeneous chemiluminescence excited by the products of sulfur-dioxide dissociation (SO + O) are presented. It is shown that heterogeneous SO + O chemiluminescence emerges not only upon the adsorption, oxidation, and desorption of reagents, but also during atom-molecule exchange O + SO2-L → SO-L + O.

Preparation Methods to Optimize the Performance of Sensor Discs for Fast Chemiluminescence Ozone Analyzers

Fast ozone (O(3)) measurements (1-50 Hz) in the atmosphere are required for airborne studies and for the measurement of ground-based O(3) fluxes by the eddy covariance technique. Fast response analyzers, based on heterogeneous chemiluminescence, need dye coated sensor discs on which the chemiluminescence is generated. In this study, we present three new preparation methods for those sensor discs. Currently available sensor discs exhibit a fast temporal decay of sensitivity, resulting in short duty times which is troublesome for many field applications. To produce sensor discs that provide more stable signals over time, three dyes and nine energy transfer reagents were tested (as well as different stoichiometric mixtures). The resulting optimal method saves 80% of the solid chemicals and shows a duty ozone dose that is prolonged by a factor of 3.5, revealing the same average sensitivity as currently available discs. In addition, we observed a strong effect of the adsorption matrix on the O(3) sensitivity, although silica discs from the same manufacturer were used. Application of the new sensor discs during field measurements showed that the results are consistent with the laboratory data.

Photofragmentation of nitro-based explosives with chemiluminescence detection

A simple, fast, reliable, sensitive and potentially portable explosive detection device was developed employing laser photofragmentation (PF) followed by heterogeneous chemiluminescence (CL) detection. The PF process involves the release of NO(x(x = 1,2)) moieties from explosive compounds such as TNT, RDX, and PETN through a stepwise excitation-dissociation process using a 193 nm ArF laser. The NO(x(x = 1,2)) produced upon PF is subsequently detected by its CL reaction with basic luminol solution. The intensity of the CL signal was detected by a thermoelectrically cooled photomultiplier tube with high quantum efficiency and negligible dark current counts. The system was able to detect trace amounts of explosives in various forms in real time under ambient conditions. Detection limits of 3 ppbv for PETN, 2 ppbv for RDX, and 34 ppbv for TNT were obtained. It was also demonstrated that the presence of PETN residue within the range of 61 to 186 ng/cm(2) can be detected at a given signal-to-background ratio of 10 using a few microjoules of laser energy. The technique also demonstrated its potential for the direct analysis of trace explosive in soil. An LOD range of 0.5-4.3 ppm for PETN was established, which is comparable to currently available techniques.

Chemiluminescent detection of neutral gaseous radicals

This paper presents a systematic approach to the development of novel solid-state chemical sensors on the basis of heterogeneous chemiluminescence. The method is applicable for the identification and measurements of concentration of H, O, and other gaseous chemical radicals, where utilization of standard techniques is difficult. The luminescence is invoked during Eley-Rideal recombination of the radicals in question on the surface of the sensor core. A technique is discussed to separate the contributions of Eley-Rideal and Langmuir-Hinshelwood mechanisms, and to select appropriate materials for the sensor emitter fabrication. Typical sensor characteristics include sensitivity of 10(5) cm(-3), working gas pressures of 10(-8) - 10(1) Torr, and measurement time approximately 1 s.

Surface Luminescence of Polycrystalline Zinc Oxide Excited by Hydrogen Atoms

ABSTRACTExcitation of a luminescence by highly exothermic chemical reaction on the surface of a luminophore provides a unique opportunity to separate surface luminescence from the bulk luminescence. This enables studies of the electronic properties of the semiconductor surfaces even if the surfaces are of complicate shapes. We have studied heterogeneous chemiluminescence (HCL) of ZnO powders. The luminescence was excited by a release of chemical energy, namely by catalytic recombination of hydrogen atoms. The HCL spectra were compared to the photoluminescence (PL) spectra. The HCL spectra were sensitive to the details of preparation and treatment whereas PL spectra almost did not change. HCL spectra of powder samples pretreated for enhancing “green” luminescence exhibited long-wavelength tail (up to 800 nm) and their maximum was blue-shifted as compared with PL spectra. Different HCL bands forming long-wavelength tail were isolated by changing the temperature of the samples. Additional milling of ZnO led to amplification of the HCL-specific surface bands. Pure ZnO showed neither PL nor HCL; however we were able to observe HCL surface bands with maxima at 610 nm and 730 nm after treatment of the sample in atomic hydrogen atmosphere at 570 K. Remarkably, such treatment did not cause appearance of the PL. The HCL in the presence of atomic hydrogen was steady in time and was caused by an abstraction of adsorbed hydrogen by incident hydrogen atoms, i.e. the reaction followed Eley-Rideal mechanism. The HCL can be utilized for in situ monitoring of the growth and evolution of ZnO in controlled atmosphere.

Sorption of Silver and Chemiluminescent Activity of Clinoptilolite

Sorption conditions of ions and colloidal particles of silver by a zeolite (clinoptilolite) and clays, and specific features of distribution of absorbed silver in clinoptilolite grains were studied. Temperature dependences of the intensity of heterogeneous chemiluminescence from samples of natural clinoptilolite and its modified forms were obtained. The activation energies of the luminescence-active chemisorption of oxygen on electron-donor centers of the zeolite surface and relative amount of centers were determined.

Chemical reactions of atomic hydrogen at SiC surface and heterogeneous chemiluminescence

In studies of the surface properties of SiC polytypes and chemical reactions of hydrogen atoms at SiC surfaces the surface (chemi)luminescence of SiC has been applied excited in the reaction of hydrogen atoms due to chemical energy released (heterogeneous chemiluminescence, HCL). The bulk photoluminescence (PL) have also been used for comparison with surface HCL. All the samples showed HCL, but only α-SiC (6H, 15R), technologically or specially doped (predominantly by N, B, Al), exhibited PL ( λ ex=365 nm). Cubic polycrystalline β-SiC (or 3C–SiC) did not show PL. The general luminescence band of α-SiC (6H, 15R) and B and Al doped SiC (6H) was a broad yellow band with λ max ranged from 620 to 650 nm for PL (110 K). Another less intensive luminescence band is a blue one, which has been observed only at low temperatures for α-SiC (6H,15R) and B and Al doped SiC (6H) in PL spectra and as a shoulder in HCL spectra ( λ max=477 nm at 110 K for 15R–SiC). The green band near 540 nm was also observed sometimes in PL spectra for α-SiC. The heat of adsorption of hydrogen atoms at polycrystalline β-SiC estimated from HCL data was found to be in the range from 2 to 3 eV.

A Luminescence Characterization of Adsorbed Hydrogen Atoms on Plasma Facing Materials

An atomic probe technique for characterization of hydrogen atoms on fusion related materials is described. The technique for determining surface coverage by hydrogen atoms or isotopes under both non-steady-state and stationary conditions is based on detection of heterogeneous chemiluminescence (HCL) excited in the interaction between adsorbed atoms and the pulsed normalized probing atomic flow. The recombination of hydrogen atoms from the gas phase was found to occur in general case via both collision Rideal–Eley (RE) and diffusion Langmuir–Hinshelwood (LH) mechanisms. The instantaneous optical response allows extracting the contributions of these two mechanisms to the overall reaction rate for various experimental conditions. The HCL method is also applicable for quick measurement of the reactivity of adatoms (in terms of the recombination coefficient γ) for all the materials including metals. The spectra and kinetics of HCL are useful for estimation of heats of adsorption for hydrogen atoms or isotopes.

Heterogeneous Chemiluminescence of Crystal Phosphors on X‐Ray or UV Irradiation

Using a high‐vacuum assembly with molecular beams and setups with an implemented atom probe, we investigated atomic and molecular adsorption luminescence of the oxides CaO‐Bi and MgO in O and O2 beams and also radical‐recombination luminescence excited by H and O atoms in ZnS and in ZnS,CdS samples activated with silver, copper, and the rare‐earth element Tm. It is established that exposure to UV light and x‐ray radiation of the CaO‐Bi, MgO, and ZnS‐Tm samples, where the mechanism of direct excitation of heterogeneous chemiluminescence (HCL) is realized, does not influence the characteristics of the heterogeneous chemiluminescence, whereas similar exposure of the ZnS,CdS‐Cu,Al and ZnS,CdS‐Ag samples and of self‐activated ZnS, in which the excitation of heterogeneous chemiluminescence is due to the ionization of the lattice, leads to an increase in the intensity of heterogeneous chemiluminescence up to five orders of magnitude. The mechanisms of the phenomenon are considered.

Heterogeneous chemiluminescence of crystallophosphor catalysts in the CO + O mixture

The results of the study of stationary and relaxation characteristics of heterogeneous chemiluminescence (HCLCO + O) of such crystalophosphor catalysts as CaO-Bi and Zn2SiO4-Mn are presented. Chemiluminescence was excited by the products of the dissociation of the CO, CO2, or O2 + CO + Ar mixture. The excitation of (HCLCO + O) generally follows the Eley-Rideal mechanism, that is O + CO-L → CO2-L +hv or CO + O-L→ CO2-L +hv, where L denotes a lattice. The stepwise kinetic mechanism of HCLCO + o excitation is suggested. The cross-sections and quantum yields of CO oxidation on the surface of CaO-Bi and Zn2SiO4-Mn are determined.

Barium oxides immobilized SO4- and NO2 as chemiluminescence reaction media.

New heterogeneous chemiluminescence(CL)reaction media based on barium oxide(BaO)CL reaction system were developed using peroxomonosulfate(KHSO5)and hydrogen peroxide(H2O2)and nitrite(NO2-).It is known that KHSO5, an oxidizing agent, is decomposed by a metal ion catalyst(Co2+)to yield reactive species(Co3+, SO4-, etc.), which are strong oxidizing agents.On the other hand, peroxynitriteONOO- and nitrogen dioxide radical(NO2)obtained by reaction between H2O2 and NO2- are also powerful oxidizing agents.We have thus tried to immobilized these active species on the surface of BaO in order to improve the capabilities of BaO as not only CL, but also various reaction media.

Unsteady-state methods of investigation of the heterogeneous chemiluminescence of phosphor crystals

Unsteady-state methods of investigation of the heterogeneous chemiluminescence of phosphor crystals

Reaction tray and noncontact transfer method for heterogeneous chemiluminescence immunoassays

We describe a reaction tray for a heterogeneous chemiluminescence (CL) immunoassay having the following features: separate sample incubation and signal detection wells; a design that allows for noncontact transfer of the reaction mixture from incubation wells to detection wells; surface features to mate with a detector and create a light-tight seal for CL detection; and self-contained means for liquid removal. The reaction mixture is transferred by injecting a wash solution from a group of nozzles into the incubation well. Quantitative transfer of microparticles (transfer efficiencies greater than 95% and CV less than 5%) is achieved by injecting two 300-microL pulses of transfer solution at a rate of 2.1 m/s. The performance of the tray and method of transfer is tested by determining the precision of CL signal for a sample containing a concentration of anti-hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (HBsAg) close to the cutoff value for the assay.

Detection apparatus for multiple heterogeneous chemiluminescence immunoassay configurations

We describe an apparatus for measuring signals emanated from two heterogeneous chemiluminescence immunoassay (CLIA) configurations: antibody-coated polystyrene beads, in reaction tray wells, and microparticles captured by a porous matrix. An optics and fluidics design which allows the use of a common detection head for these two different assay configurations is described. The detection head moves along three Cartesian coordinates to create a localized light-tight compartment around each individual disposable reaction vessel. Reproducibility of the light seal, trigger solution delivery, and mixing is achieved for acridinium-labeled CLIA. The coated polystyrene beads configuration is tested using βHCG, CEA, and TSH assays. The microparticle-capture configuration is tested using βHCG and HBsAg assays. The microparticle capture CLIA has shorter incubation times and the potential for ease of automation.