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1
Content available Infrared studies and spectral properties of photochromic high silica glasses
Girsova M A, Golovina G F, Drozdova I.A., Polyakova I G, Antropova T V
Optica Applicata
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2014
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Vol. 44, nr 2
337--344
EN
The structure of photochromic high silica glasses (PHSGs) was studied by UV–VIS–NIR and IR spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. PHSG plates were obtained by impregnation of silica porous glasses at first with AgNO3 aqueous solution (in or without the presence of the sensitizers, such as Cu(NO3)2 or Ce(NO3)3), next in the mixed halide salt (NH4Cl, KBr, KI) solution. Then a part of the samples was sintered at temperatures from 850 to 900 °C up to closing of the pores. The results of TEM study have shown that the PHSG plates have two-phase structure with inclusions of the size of 10–100 nm. According to XRD data, the PHSGs contain the AgBr phase. IR spectra confirmed the presence of AgI, AgCl, CeO2, CuCl2, CuCl phases in PHSGs.
2
Content available remote The influence of thermal treatment of the porous glass plates on the character of their scattering in visible spectral region
Antropova T. V., Anfimova I. N.
Optica Applicata
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2010
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Vol. 40, nr 2
285--291
EN
The pore structure and light transmission of the high-silica porous glasses in visible spectral region are investigated depending on a temperature of their thermal treatment and composition of the initial two-phase alkali borosilicate glasses. The character of light transmission in porous glasses is analyzed considering the features of their pore space structure and processes occurring in porous glass upon heating. It is shown that with an increase in temperature of thermal treatment of the porous glasses of different composition the pore size increases, and their specific surface decreases (at practically constant common porosity), which is due to the processes of pore overcondensation, that occur owing to the regrouping and change of packing density of the secondary silica particles. It is shown that introducting phosphate and fluoride ions in the basic alkali borosilicate glass results in an increase in the light attenuation factors of the porous glasses owing to an increase in the sizes of liquation areas of heterogeneity in initial two-phase glasses, formation of larger pores and presence of the nanostructured microcrystalline phases in the porous glasses.
3
Content available remote Porous glasses as a substrate for sensor elements
Evstrapov A., Esikova N., Rudnitskaya G., Antropova T. V.
Optica Applicata
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2010
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Vol. 40, nr 2
333--340
EN
The properties of porous glasses are determined by optical spectroscopy and high-resolution microscopy at different stages of immunoglobulin immobilization and after immune reaction. The influence of duration and temperature of drying between surface activation and silanization is studied. The quantity of protein immobilized on the porous glass surface is estimated by the Coomassie method. Various ways of surface silanization with the use of toluene and acetone are compared. The possibility of fabricating a microsensor element based on the porous glass for microchip is presented.
4
Content available remote Determination of electrokinetic potential of porous glasses by methods of streaming potential, electroosmosis and electrophoresis
Volkova A., Ermakova L., Volkova M., Antropova T. V.
Optica Applicata
|
2010
|
Vol. 40, nr 2
341--349
EN
Complex research of structural and electrokinetic characteristics of nano- and the ultraporous glasses prepared from sodium borosilicate (SBG) glass DV1-Sh in KCl background solutions of various concentrations in a wide pH range has been performed. It is shown that for ultraporous membranes with the sizes of porous channels r in the range 10–70 nm appreciable electroosmotic flows and a good agreement of electrokinetic potential values determined by three different methods are observed. It is established that for nanoporous (r < 10 nm) glass membranes change of electroosmotic flow velocity with time is due to the development of concentration polarization.
5
Content available remote Application of high resolution microscopy and optical spectroscopy for study of phase separation in phosphorus- and fluorine-containing sodium borosilicate glasses
Antropova T. V., Drozdova I., Kukhtevich I., Evstrapov A., Esikova N.
Optica Applicata
|
2010
|
Vol. 40, nr 2
293--304
EN
The kinetics of phase separation in glass-forming Na2O–B2O3–SiO2–P2O5–|F| system and structure parameters of the two-phase glasses have been investigated by transmission electron microscopy (TEM) and optical spectroscopy methods. The TEM images were analyzed with the help of specially designed software for the purpose of determination of the relative volume and size of the phases. An influence of duration of a glass heat treatment on the parameters of their structure was investigated at a temperature of 550 °C which is necessary for prompting a two-network structure and is most frequently used for manufacturing porous glasses. The time of glass heat treatment necessary for achieving phase equilibrium was established. A deviation of the phase inhomogeneity growth rate from theoretical one was determined. It was revealed that a certain third phase, the composition of which can include ?-quartz, is formed in glass during the heat treatment. Fluorescence of the two-phase glass which has been subjected to heat treatment for a long time can be caused by the presence of this phase.
6
Content available remote Spectral characteristics and structure of porous glasses
Evstrapov A., Esikova N., Antropova T.V.
Optica Applicata
|
2005
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Vol. 35, nr 4
753-759
EN
The paper presents a method for the size estimation of scattering structures in porous glasses, being based on measurements of both the sample reflection and transmission. Analysis of the transmission spectra allows us to estimate the contribution of absorption and scattering to light extinction and to choose a wave range where the characteristics of a medium can be determined by means of simple and effective models. Optical characteristics of the highly light scattering samples can be obtained with use of the Gurevich-Kubelka-Munk method.
7
Content available remote Interface interactions and optical properties of novel photonic nanocomposites consisting of porous glasses doped with organic luminophore molecules
Antropova T.V., Baran J., Gavrilko T., Gnatyuk I., Morawska-Kowal T., Melnik V., Puchkovska G., Vorobjev V.
Optica Applicata
|
2005
|
Vol. 35, nr 4
725-733
EN
Absorption and luminescence spectra of nanocomposites consisting of photonic molecules rhodamine 6G, trishydroxyquinoline aluminum (Alq3) complex and benzophenone adsorbed on soda-borosilicate porous glasses from ethanol and dichloromethane (DCM) solutions are investigated. The effect of sorption interactions at the interface between the glass pore surface and the organic media on luminescent and optical characteristics of the nanocomposites was investigated by NIR spectroscopy. It was shown that spectral changes observed in the absorption and emission spectra of the luminophores in the porous glasses are determined by the balance between physical interaction of the organic molecule with different adsorption centers on the pore walls and solvation effect.
8
Content available remote Effect of structure parameters and composition of high-silica porous glasses on their thermal and radiation resistant properties
Antropova T.V., Volkova A.V., Petrov D.V., Stolyar S.V., Ermakova L.E., Sidorova M.P., Yakovlev E.B., Drozdova I.A.
Optica Applicata
|
2005
|
Vol. 35, nr 4
717-723
EN
The influence of a composition of initial phase-separated alkali borosilicate glass and its thermal treatment as well leaching conditions on the parameters of the porous glass structure are discussed. The results obtained by adsorption and conductivity methods, transmission electron microscopy and dilatometer technique were used to analyse the effect of structure parameters and composition of high-silica porous glasses on their thermal and radiation resistant properties.
9
Content available remote Application of electron microscopy methods to the study of porous and quartz-like glasses
Drozdova I.A., Antropova T.V., Tolkachev M.D.
Optica Applicata
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2005
|
Vol. 35, nr 4
709-715
EN
The structure of high-silica porous glasses and quartz-like (Vycor type) glasses has been investigated by transmission and scanning electron microscopy and by electron micro-probe analysis. Porous glasses (PGs) have been manufactured by acid leaching of phase-separated alkali borosilicate glass plates. To obtain the quartz-like glasses the PG samples were sintered at different temperatures up to 900°C. Before sintering a part of PGs was impregnated with salt solutions containing Ag. Features of the structure of quartz-like glass matrix are revealed. The parameters and arrangement of a photosensitive Ag-Hal phase in photochromic quartz-like glasses are determined.
10
Content available remote Sintering of optical porous glasses
Antropova T. V., Drozdova I. A.
Optica Applicata
|
2003
|
Vol. 33, nr 1
13-22
EN
The changes in the visible light transmission of the optical porous glasses (PGs), arising from PGs thermal treatment, have been investigated by transmission electron microscopy and optical spectroscopy technique. Also the PGs thermal properties such as linear shrinkage and viscosity have been studied. These PGs are used in optics and laser technology as the base for the micro- optical elements produced by a local laser sintering of PGs.
11
Content available remote Optical properties and structure of porous glasses
Evstrapov A. A., Antropova T. V., Drozdova I. A., Yastrebov S. G.
Optica Applicata
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2003
|
Vol. 33, nr 1
45-54
EN
The results of measurements concerning spectral dependences of transmission and reflection coefficients both for porous and two-phase glasses are presented. Relative estimations have been performed for transmission and reflection coefficients of examined samples. Optical characteristics, such as the dispersion of refractive index and absorption coefficient, have been found for porous glasses. Porosity of the material and the sizes of micropores have been determined from the optical characteristics of glasses with the assumption of identity and uniformity of pores.
12
Content available remote Porous glass: inhomogeneities and light transmission.
Antropova T.V., Drozdova I.A., Yastrebov S.G., Evstrapov A.A.
Optica Applicata
|
2000
|
Vol. 30, nr 4
553-568
EN
Basic optical characteristics were studied to reveal the structure of porous glass samples. Acid leaching technology was used to manufacture porous glasses from the bulk of phase-separated alkali borosilicate glasses. The transmission electron microscopy, selected area diffraction and shadow graph techniques, optical microscopy and spectrophotometry, reflective ellipsometry were used to obtain new information about some inhomogeneities such as strata and spindle-like silica precipitates as well as boron containing microcrystalline phases inside porous glasses.
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