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1
Content available remote Ferroelektryki w szkłach porowatych
Rysiakiewicz-Pasek E., Poprawski R.
Szkło i Ceramika
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2009
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R. 60, nr 6
4-7
PL
W pracy przedstawiono metody wprowadzania wybranych materiałów ferroelektrycznych (TGS, NaN02 oraz KN03) w matryce szkieł porowatych o różnych średnich rozmiarach porów. Na podstawie pomiarów właściwości elektrycznych (piroelektrycznych i przenikalności elektrycznej) oraz termicznych (rozszerzalności termicznej i ciepła właściwego) stwierdzono, że w otrzymanych kompozytach sekwencje przemian fazowych są takie same jak w kryształach litych. Wykazano, że temperatury przemian fazowych zależą od rozmiarów porów.
EN
The methods of introducing of selected ferreoelectrics materials (TGS, NaN02 and KN03) into porous glasses matrix with different pores size were presented. On the basic on measurements of electrical (pyroelectric, dielectric permittivity) and thermal (thermal expansion, specific heat) properties it was stated that sequence of phase transitions are similar to those in bulk crystals. It was shown that the temperature of phase transitions depends on pore dimensions.
2
Content available remote Szkła porowate w procesie filtracji piwa.
Środa M., Szumera M., Wodnicka K.
Szkło i Ceramika
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2003
|
R. 54, nr 3
32-35
PL
W pracy przedstawiono proces otrzymywania szkła porowatego w oparciu o metodę z użyciem wypełniacza nieorganicznego (Na2SO4, K2SO4). Szkło to porównano z obecnie stosowana w przemyśle browarniczym ziemią okrzemkową. Wykonano badanie porowatości, gęstości i powierzchni właściwej. Przeprowadzone badania sedymentacji związków organicznych w piwie przed procesem filtracji wykazały, że otrzymane materiały, na bazie szkła Termisil, wpływają na zwiększenie szybkości sedymentacji, a co za tym idzie skrócenie czasu filtracji piwa.
EN
The process of porous glass formation by means of inorganic fillers (Na2SO4, K2SO4) was presented in the papaer. The properties of the glasses were compared with the diatomaceous earth used in the brewery industry nowadays. A porosity, density and the specific surface of the glass and diatomites were studied. It was observed the sedimentation process was hastened in the presence of the Termisil porous glass.
3
Content available remote Small doses γ-irradiation effect on the photoluminescence properties of porous glasses
Doycho I. K., Gevelyuk S. A., Kovalenko M. P., Prokopovich L. P., Rysiakiewicz-Pasek E.
Optica Applicata
|
2003
|
Vol. 33, nr 1
55-65
EN
The g-irradiation effect on the photoluminescence of various types of porous silica glasses and on its change during a half-year storage has been studied. It has been revealed that the photoluminescence intensity of glasses with fine matrix and almost complete absence of silica gel does not change when irradiated at applied doses, but a long-wave shift of its maximum position is observed. The increase in photoluminescence intensity appeared to be the most stable in glasses with the thick-wall matrix. The model which explains apparent changes in photo-luminescent properties and also allows us to draw conclusions about some features of various types of porous silicate glasses structure has been presented.
4
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.
5
Content available remote Pore size determination by positron annihilation lifetime spectroscopy
Jasińska B., Dawidowicz A. L., Goworek T., Wawryszczuk J.
Optica Applicata
|
2003
|
Vol. 33, nr 1
7-12
EN
Two Vycor glasses were investigated using PALS method. The model of pick-off annihilation in cylindrical free volume was applied to evaluate the pore radii. The o-Ps mean lifetime value in the pores changed from 6.5 to 40 ns in one glass, while from 13 to 51 ns in the other (softer) one. The determined pore radii, using a cylindrical shape model, were from 0.5 to 1.4 nm and from 0.7 to 1.6 nm, respectively.
6
Content available remote Physical adsorption in porous glasses
Ovechko V., Dmytruk A., Mygashko V.
Optica Applicata
|
2003
|
Vol. 33, nr 1
41-44
EN
We have presented the results of our investigation concerning adsorption in porous glass (PG). Chemical adsorption of gas molecules is due to indicator substances which were deposited from solution on the surface of pores. Physical adsorption of organic molecules is due to OH-adsorption centres which are always arranged on the surface of PG at room temperature. Adsorption processes were investigated with infrared spectroscopy.
7
Content available remote Optical properties and structure of porous glasses
Evstrapov A. A., Antropova T. V., Drozdova I. A., Yastrebov S. G.
Optica Applicata
|
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.
8
Content available remote Nanoparticles of lead sulfide in porous glasses prepared by the sol-gel method
Reisfeld R., Sarajdarov T., Minti H., Wodnicka K.
Optica Applicata
|
2003
|
Vol. 33, nr 1
61-73
EN
PbS semiconductor nanoparticles were grown inside the matrices of zirconium oxide (ZrO2) and zirconium-silica-polyurethane (ZSUR) prepared by the sol-gel method. Zirconium ormosil included polyurethane used to control the growth and aggregation of PbS nanoparticles. The new matrix allows the incorporation of up to 40% PbS forming a characteristic structure of dendrite by reacting lead acetate with ammonium thiocyanate in the sol-gel matrix. The sol precursors of the matrix for ZSUR contain ZrO2 matrix solution, epoxy-silica-ormosil (ESOR) and diurethane siloxane (DURS) synthesized separately. The size of nanoparticles as determined by transmission electron microscopy (TEM) ranges between 2–4 nm for 20% PbS in zirconium oxide and 8–10 nm for 20% PbS in ZSUR matrices. The porosity of the glasses is determined using the nitrogen adsorption technique. The pore size for ZSUR doped with 2% of PbS as determined by BET is 1.54 nm. Quantum size effect was observed from the shifts of absorption and photoluminescence (PL).
9
Content available remote Evaluation of thin Ta(N) film integrity deposited on porous glasses
Shamiryan D., Baklanov M. R., Yanovitskaya A. V., Zverev A. V., Tőkei Z., Iacopi F., Maex K.
Optica Applicata
|
2003
|
Vol. 33, nr 1
91-96
EN
Porous glasses are widely used in microelectronics as inter-metal dielectrics with low dielectric constant (so-called low-k dielectrics). At the same time copper is used as a metal because of its low resistivity. Combination of Cu and low-k requires a barrier to prevent Cu diffusion into a low-k dielectric. Integrity of such a barrier becomes an issue when porous glass is used as a low-k dielectric. The barrier should be as thin as possible and fully dense at the same time. Using solvent (toluene) penetration through a barrier (tantalum nitride in our case, which is non-stoichiometric, hence denoted as Ta(N)) and adsorption in porous glass as a barrier integrity probe, we show that barrier integrity depends not only on porous structure of the glass, but also on its chemical composition (namely on carbon content). Glasses with high carbon content are easier to seal with Ta(N) barrier. With help of Monte Carlo simulations, we speculate that different chemical composition of the porous glass results in different surface diffusion during barrier deposition. Different surface diffusion, in turn, results in different integrity of the porous barrier.
10
Content available remote Effect of antibiotic insertion on photoluminescent properties of silicate porous glasses used in ophthalmologic prostheses
Rysiakiewicz-Pasek E., Gevelyuk S. A., Doycho I. K., Prokopovich L. P., Safronsky E. D.
Optica Applicata
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2003
|
Vol. 33, nr 1
33-39
EN
The selection of silica porous glass being the most suitable material for manufacturing of the actuated scleral part of the eye prosthesis has been justified. The model explaining the photoluminescence intensity oscillations of porous glass during the effusion of the antibiotic out of the glass has been proposed. Multiple usage of the antibiotic has been found to lead to the etching effect of the porous glass and a method of minimization of the effect has been presented.
11
Content available remote Application of NIR spectroscopic method to the study of porous glasses filled with liquid crystals
Gavrilko T., Gnatyuk I., Puchkovska G., Baran J., Marchewka M., Morawska-Kowal T.
Optica Applicata
|
2003
|
Vol. 33, nr 1
23-32
EN
The paper focuses on NIR spectroscopic studies of the structure of surface active centers and interface interactions in novel nanocomposition materials built of nanoporous glasses (PG) and n-alkylcyanobiphenyl (nCB) liquid crystals (LC). NIR (12000–4000 cm–1) spectra of bare PG with pore size ranging from 2 to 10 nm and those loaded with nCB (n = 2, 4, 5, 8) were investigated at room temperature for two types of PG of variable surface activity preheated to 200 °C (type I) and 600 °C (type II). The number of surface active centers for the two types of PG has been evaluated as a function of pore diameter, and the relative number of the LC molecules directly bounded to the pore active centers was estimated.
12
On-line calibration system for chromatographic detectors based on thermal decomposition process of surface compounds
Przyk E., Konieczka P., Łobuch E., Biernat J.F., Namieśnik J.
Chemia i Inżynieria Ekologiczna
|
2001
|
Vol. 8, nr 8-9
905-910
EN
The preparation of gas standard mixtures of ethene, based on thermal decomposition of modified bed surfaces has been described. The aim of this research was to compare of results obtained for different porous materials (silica gel; porous glass) using for modification. Relations between amount of ethene liberated and thermal decomposition time have been determined and presented in as a mathematical equation.
PL
Opisano metodę sporządzania gazowych mieszanin wzorcowych etenu, wykorzystującą termiczny rozkład związków powierzchniowych. Celem pracy było porównanie wyników uzyskanych dla rożnych porowatych materiałów (żel krzemionkowy, szkło porowate) użytych w procesie modyfikacji. Wyznaczono też zależności między ilością powstającego etenu a czasem prowadzenia procesu termicznego rozkładu i opisano ją zależnością matematyczną.
13
Nanostructure of some porous materials studied by SAXS.
Pająk L., Jarzębski A.B., Mrowiec-Białoń J., Bierska B.
Archiwum Nauki o Materiałach
|
2001
|
T. 22, nr 2
107-114
PL
Struktura większości materiałów porowatych jest zazwyczaj złożona. Porowatość materiałów (część objętości materiału zajmowana przez pory) może się zmieniać w szerokim zakresie, osiągając w aerożelach nawet wielkość powyżej 99%. W ostatnim dwudziestoleciu osiągnięto znaczący postep w opisie złożonych, nieuporządkowanych struktur materiałów porowatych poprzez wprowadzenie geometrii fraktalnej. Obecnie przyjmuje się, że modele fraktalne struktury por lepiej opisują rzeczywistą strukturę aniżeli klasyczne, proste modele. Metoda małokątowego rozpraszania promieni rentgenowskich (SAXS) jest szczególnie użyteczna w badaniach materiałów porowatych, niejednorodnych w skali 10-1000 angstremów. Badania struktury wybranych materiałów porowatych wykonano dla aerożeli o szkielecie zbudowanym z SiO2 i ZrO2, żelu krzemionkowego, krzemionki pirogenicznej, szkła porowatego, elektroosadzanego metalu i różnych materiałów węglowych. Natężenie małokątowego rozpraszania analizowano głównie na podstawie prawa potęgowego rozpraszania. Podano przykłady materiałów porowatych o strukturze typu fraktali masowych, powierzchniowych i porowych. Wyznaczono odpowiednio wartości masowych, powierzchniowych i porowych (Dm, Ds i Dp) wymiarów fraktalnych.
EN
The structure of most porous materials is quite complex. The porosity of materials (total volume fraction of material occupied by pores) can vary in a very broad range, from much less than 1% up to more than 99% in the case of aerogels. In the last two decades the characterisation of the complex, disordered structure of porous materials has made a milestone progress owing to the use of fractal geometry. At present it is generally accepted that the fractal models of pore structure describe the real structure better than the classical models which assume the existence of macro-, meso- and micropores of simple geometry. The small-angle X-ray scattering (SAXS) method is specially useful in the studies of porous materials in the length scale 10-1000 angstroms. The SAXS studies were performed on dry, porous materials like silica and zirconia aerogels, conventional silica gel, fumed silica, porous glass, electrodeposited metal and different carbonaceous materials. The scattering intensities I(q) were tested mainly in terms of power-law equation . The examples of porous materials with mass, surface and pore fractal morphology are given. Mass surface and pore fractal dimensions (Dm, Ds and Dp) were estimated, respectively.
14
Content available remote Porous glasses as a host for solid state tunable lasers in the visible as a means for fluorescence diagnostics and photodynamic therapy.
Reisfeld R, Yariv E.
Optica Applicata
|
2000
|
Vol. 30, nr 4
481-490
EN
Lasers prepared by incorporation of the active dyes into porous glasses are described. The background of the use of lasers for photodynamic therapy and diagnostics is outlined. The role of hematoporphyrin and hypericin in creation of singlet oxygen which destroys the malignant tissues, is explained. The lasers, based on sol-gel technology, incorporated by several perylimide and pyrromethane dyes emit in the suitable range in which the hematoporphyrin is excited. These compact lasers may replace, in the future, the vapour and the liquid lasers. The synthesis and the spectroscopic properties of the laser are described.
15
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.
16
Content available remote Optical gate controlled by temperature.
Meshkovsky I.K., Fuad M.A, Alyev F.M., Baushev V.N.
Optica Applicata
|
2000
|
Vol. 30, nr 4
581-583
EN
Light scattering and transmission of a porous silicate glass-based composition material with poly-2-ethylhexylactylate immobilized in the pores have been investigated. A temperature transition (47-50 degrees C) in transmittance has been observed and interpreted. The hysteresis found indicates that the second order transition occurs.
17
Content available remote Linear extension of porous glasses with modified internal surface in humid environment.
Gevelyuk S. A., Doycho I. K., Lishchuk D. E., Prokopovich L. P., Safronsky E. D., Rysiakiewicz-Pasek E., Roizin Y. O.
Optica Applicata
|
2000
|
Vol. 30, nr 4
605-611
EN
An original interferometric technique for investigating the influence of humidity on change in the linear dimensions of porous silica glasses is developed. The linear dimensions of a specimen are shown to change as a result of competition in the system of compressive capillary forces and expansion forces arising from the swelling of the residual silica gel present in pores. The possibility of selective inhibition of the capillary squeezing forces or the silica gel expansion forces by the pre-treatment of a porous material by a hydrophobized composition (hexamethyldisilazan - HMDS) or by annealing of carbon impregnated inside of the pores is shown experimentally.
18
Content available remote Influence of gamma -irradiation on the photoluminescent properties of porous glasses.
Gevelyuk S.A., Lishchuk D.E., Mak V.T., Rysiakiewicz-Pasek E., Marczuk K.
Optica Applicata
|
2000
|
Vol. 30, nr 4
595-603
EN
The influence of small doses of gamma -irradiation on the features of the photoluminescence spectra of porous silica glass during long-time (several months) storage after the irradiation is investigated. The non-monotonic dependence of photoluminescence change on the dose of the glasses with a different composition and different additional pre-treatment is observed. The analysis of intensity changes and shifts of the maxims of the photoluminescence spectra shows long-time oscillations. This indicates that the composite catalytic processes take place on the surface of the pores. Perhaps the small gamma -radiation doses initiate the cyclic process of the surface state transformation on the inner side of the pores.
19
Content available remote High temperature treatment of porous glasses.
Marczuk K., Pater K.
Optica Applicata
|
2000
|
Vol. 30, nr 4
619-625
EN
The influence of thermal treatment on linear sizes and the internal structure of porous glasses has been investigated. A simple connection between porosity and shrinkage has been confirmed to exist except in microporous glasses with silica gel inside the pores, where in the initial stage of annealing the porosity was increasing when the glass shrank. A sponge structure of fracture mirrors of the walls of a carcass for glasses heated at about 650 degrees C is observed.
20
Content available remote High radiation durability of optical elements made of porous glass.
Meshkovsky I.K., Safin V.M, Stepanov V.E.
Optica Applicata
|
2000
|
Vol. 30, nr 4
591-593
EN
Optical properties of elements made of silicate porous glass are measured after their exposure to gamma -radiation. Extraordinary radiation durability of porous glass has been found and interpreted.
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