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1

The phase separation phenomenon in the Na2O–B2O3–SiO2–Fe2O3 glass-forming system and its application for producing porous glasses

Konon Marina, Antropova Tatyana, Polyakova Irina, Anfimova Irina, Dikaya Lidiya, Semenova Ekaterina, Kurilenko Ludmila

Optica Applicata

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2019

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Vol. 49, nr 3

437--444

EN

Glasses in the Na2O–B2O3–SiO2–Fe2O3 system with a constant SiO2 content 70 mol% were synthesized using conventional melting in platinum crucibles in SiC-furnace in air. After synthesis and annealing, glasses were heat treated at 550°C for 96–144 hrs to promote phase separation. A tentative region of phase separation for this temperature was outlined. X-ray powder diffractometry results showed three iron-containing phases (Fe3O4, FeSiO3 and β-Fe2O3) forming in the investigated glasses with magnetite being the main phase as it is observed in most of the glasses. Chemical durability studies showed that compositions of phase-separated glasses suitable for synthesis of porous glasses, both iron-free and iron-containing lie in between 4 and 8 mol% of Na2O. Bulk samples of porous glasses were obtained within the chosen region having the following parameters: specific surface area 40–185 m2/g, porosity 30%–45%, pore diameter 3–14 nm. The parameters of porous structure of iron-containing porous glasses are of the same order of magnitude as the porous glass used for the multiferroic nanocomposite synthesis.

2

Nature of gas sensitivity of dyes on the base of Sn(IV) complexes

Doycho Igor K., Gevelyuk Sergiy A., Lepikh Jaroslav I., Rysiakiewicz-Pasek Ewa

Optica Applicata

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2019

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Vol. 49, nr 3

427--436

EN

Sensitivity of dyes on the base of 4-valence tin complexes to the composition of environment was researched. It has been found out that such dyes by themselves keep stability and inactivity to the composition of atmosphere. However, the photoluminescence properties of the nanostructures on their base can differ sufficiently depending on conditions of their formation. So the glow intensity of the nanoparticle ensembles of dyes having amine substitute in the hydrazonic fragment depends on the concentration of solution which was used during their formation. Optimal concentration exists and its excess leads to weak luminescence due to concentration quenching. Thus, if the nanoparticle ensemble, which was formed at the optimal concentration will be placed into ammonium atmosphere, it will be equivalent to formation of this ensemble by inflated concentration of the saturated solution. So photoluminescence of such system will be weak. Thereby reduced glow intensity will keep sufficiently long time due to the appearance of leakage channels in the form of bridge bonds. In such manner one can register the presence of ammonium in the environment. Initial intensity of luminescence may be re-established by removing extraneous gas with the aid of the short-time low-temperature anneal. In addition, the ligand in the coordination set of the dye plays a part of an interstitial impurity, so its presence leads to certain distribution of the charges in the system. It has been estimated experimentally that less intensive glow corresponds to the charge distribution in the system with the one-dentant ligand, namely by higher content of chlorine ions than in the case of bi-dentant one. This difference is more evident for dyes having hydroxyl substitute in the hydrazonic fragment. Thus, if the nanoparticle ensemble of such dye having a bi-dentant ligand will be placed into the atmosphere containing hydrogen chloride vapours, it changes the charge distribution to the typical one for the dye having one-dentant ligand artificially. It also will lead to weakening of the glow of the system. Initial intensity of luminescence may be re-established by removing the extraneous gas again with the aid of the anneal by the same conditions. The usage of specified properties makes it possible to construct reliable and responsive detectors of ammonium or hydrogen chloride vapours by the change of the detecting element in the known luminescence gas sensors to the nanoparticle ensemble of an appropriate dye.

3

PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

Gorgol M., Jasińska B., Reisfeld R.

Nukleonika

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2015

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Vol. 60, No. 4, part 1

717--720

EN

A thermal stability of three materials: undoped reference Vycor glass, glass filled with ROT-305 red dye, and silver nanoparticles was investigated by positron annihilation lifetime spectroscopy (PALS) in a broad temperature range (from 93 to 473 K). The attempt of pore size calculations from the ortho-positronium lifetime data was performed using the extended Tao-Eldrup (ETE) model. Below room temperature, a significant decrease in lifetime values of the longest-lived component was found for all the samples. This effect could not be explained by thermal shrinkage of the material and is probably caused by interaction of -Ps with a Vycor glass matrix. The greatest discrepancy from the ETE model predictions was observed for the reference glass. Doping the base material with dye molecules and silver nanoparticles resulted in similar small decrease in this discrepancy. After reheating the samples to the room temperature, the PALS components returned to the initial values. In the temperature range of 293–473 K, quite good agreement between PALS results and the ETE model predictions was observed for the reference glass and the glass incorporated with dye molecules. The observed small discrepancy in this range could possibly be partly explained by thermal expansion of the material. For the glass doped with silver nanoparticles, a significant change in PALS parameters was observed in the temperature range from 403 to 473 K.

4

Inverse gas chromatographic studies on porous glass

Rueckriem M., Hahn T., Enke D.

Optica Applicata

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2012

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Vol. 42, nr 2

295-306

EN

Porous glass is a well suitable system for the exploration of new characterization techniques due to adjustable texture properties and the possibility to "tailor-made" the surface chemistry. In this study porous glass beads were utilized as model system for the evaluation of inverse gas chromatography (IGC). Mesoporous glass beads with 10 and 20 nm pore size and macroporous glass beads with 50 nm pore size were synthesized and modified by thermal treatment and chemical reaction with hexamethyldisilazane (HMDS), ethyl-, propyl-, butyl- and octyldimethylchlorosilane. The correlations between the textural properties and the dispersive surface energy were investigated by means of the IGC technique. Furthermore dependences between surface chemistry and surface energy were pointed out on the basis of IGC measurements.

5

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.

6

Effect of restricted geometry on structural phase transitions in KH2PO4 and NH4H2PO4 crystals

Tarnavich V., Korotkov L., Karaeva O., Naberezhnov A., Rysiakiewicz-Pasek E.

Optica Applicata

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2010

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Vol. 40, nr 2

305--309

EN

The dielectric response of crystalline NH4H2PO4 and KH2PO4–SiO2 and NH4H2PO4–SiO2 composites prepared by embedding salts into porous glasses with the average pore diameter of 320 nm has been studied at the temperature range of 85–300 K. An increase of the structure phase transition temperatures in embedded salts has been observed, which is supposedly due to tensile deformations of embedded crystalline particles. The antiferroelectric phase transition in confined ADP particles becomes diffuse in the temperature region around 10 K.

7

Aggregation of dyes in porous glass

Tyurin O. V., Bercov Y. M., Zhukov S. O., Levitskaya T. F., Gevelyuk S. A., Doycho I. K., Rysiakiewicz-Pasek E.

Optica Applicata

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2010

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Vol. 40, nr 2

311--321

EN

The research examines the interaction of dye molecules with their dimers (H aggregates) and the more complex formations (J aggregates) developing in porous glass. The use of porous glass when dealing with dye aggregation has resulted in obtaining photoluminescence dimers of the J aggregating dye, the formation of which is difficult under normal conditions. In addition, the porous glass matrix contributes to a substantial reduction in the interaction of photoexcited states of both a molecular and an aggregated dye, thus helping maximize the luminescence efficiency of porous glass-distributed dyes.

8

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.

9

The photoluminescent properties of CdS clusters of different size in porous glasses

Rysiakiewicz-Pasek E., Polańska J., Gevelyuk S.A., Doycho I.K., Mak V.T., Zhukov S.A.

Optica Applicata

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2008

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Vol. 38, nr 1

93-100

EN

CdS nanoclusters were formed in the porous glass matrix by sequential chemical deposition from liquid-vapor phase and their chemical content was investigated. The room temperature photoluminescence spectra of specimens excited with a 235 nm wavelength had typical narrow peaks at 400 nm. The peaks can be explained by quantum effects for charge carriers confined inside the small-size (radius of the order of several nanometers) clusters. At the same time the luminescence spectra of the same specimens, but excited with a xenon lamp at 77 K, had peaks at ~700 nm that approximately corresponded to the band gap of the crystalline CdS. The possibility of the crystallites existence follows from the size distribution of voids in the porous glass matrix and is confirmed by the X-ray spectra typical of the wurtzite structure. The peculiarities of the observed luminescence spectra are explained by the energetic diagram of CdS in the configurational space.

10

The influence of preparation technology on phase transitions in NaNO2 embedded into porous glass

Rysiakiewicz-Pasek E., Jagus P.

Optica Applicata

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2008

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Vol. 38, nr 1

101-107

EN

The dielectric properties of sodium nitrite embedded into porous glasses with the average pore diameter of 45 nm and 320 nm have been studied. The samples were obtained by immersion of empty porous glass into the melted NaNO2 and then they stayed there for 24 and 8 hours. The sequence of phase transitions (PT) from the paraelectric phase to the sinusoidal antiferroelectric phase and to the ferroelectric phase has been observed in these nanocomposite materials on cooling. It is shown that due to the size effect, the temperatures of these PTs are lower than in bulk NaNO2

11

Morphology of porous glasses. Colloid-chemical aspect

Antropova T.

Optica Applicata

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2008

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Vol. 38, nr 1

5-16

EN

A summarizing of the results of complex study of pore morphology of porous glasses has been carried out taking into consideration the dissolved secondary silica state in the systems alkali borosilicate glass - a leaching solution. An influence of the composition and phase structure of an initial glass, and their leaching conditions, on the colloid-chemical characteristics of the porous glasses has been shown. The polymodal micro porous substructure and meso porous one, the size and a form of the pores and secondary silica particles as well as the fractal dimensions of their aggregates, the coefficients of structural resistance and tortuosity of the pores has been discussed.

12

NO2 optical fibre sensor based on porous glass probe

Dorosz D., Procyk B.

Molecular and Quantum Acoustics

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2008

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Vol. 29

65-72

EN

Nitrogen dioxide optical fibre sensor based on nanoporous glass probe was obtained. As a sensor probe glasses from the Na2O-B2O3-SiO2 system modified with TiO2 and ZrO2 and Al2O3 have been made. Porous glasses based on silica posses very good thermal and chemical durability, they are also transparent in the wide of spectrum range. It makes also possibility of use this kind of material as an optical sensor element, operating in hard working conditions. The presented design consists in the spectroscopic changes caused by the specific coloration reactions between NO2 and organic reagents placed in the nanopores. The presented different sensing reagents are compared and allow to achieve ppb NO2 level detection. High specific surface area (200 m2/g) and stable pores distribution in the size of obtained glasses assured good repeatability of the sensor.

13

Szkła odpadowe do produkcji specjalnych materiałów porowatych.

Ciecińska M.

Szkło i Ceramika

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2007

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R. 58, nr 1

9-13

PL

Aktualnie istotnym problemem jest właściwe wykorzystanie szkieł odpadowych, szkło stanowi bowiem cenny materiał, posiadający zdolność wielokrotnego recyklingu. Przedmiotem niniejszej pracy jest opracowanie skutecznej metody wytwarzania materiałów porowatych z wykorzystaniem szkieł odpadowych w postaci stłuczki szklanej. Jako surowiec podstawowy zastosowano stłuczkę szkła gospodarczego oraz stłuczkę szkła laboratoryjnego Termisil. Do wytworzenia szkłopochodnych materiałów zastosowano metody stosowane dotąd w ceramice specjalnej. Polegają one na spiekaniu proszków szklanych z różnymi środkami porotwórczymi w postaci substancji organicznych lub nieorganicznych. W wyniku zaproponowanych technologii otrzymano makroporowate szkła i materiały szkłopochodne o porowatości całkowitej od 35 do 66% i gęstości od 2,46 do 2,85 g/cm sześcienny. Wytwarzać można w ten sposób materiały filtracyjne do różnych zastosowań.

EN

The essential problem at present has become the proper management of glass wastes, considering the fact that glass represents a valuable material suitable for repeated recycling. The aim of the present study is the development of an effective method of producing porous materials by utilizing glass waste in the form of cullet. As the basic raw materials there were used the cullet of domestic glassware and the cullet from the laboratory glass Termisil. To obtain the glass-derived materials the author used the methods applied so far in special glass-ceramics. These methods consist in sintering glass powders with various porecreating agents in the form of organic or inorganic substances. As a result of the application of the proposed production technology there have been obtained macroscopic glasses, glass-derived materials of 34-66% total porosity and density from 2,46 to 2,85 g/cubic cm. Using this method it is also possible to obtain filter materials for various applications.

14

Spectral characteristics and structure of porous glasses

Evstrapov A., Esikova N., Antropova T.V.

Optica Applicata

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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.

15

Porous glasses with sodium nitrite impregnations

Rysiakiewicz-Pasek E., Poprawski R., Urbanowicz A., Mączka M.

Optica Applicata

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2005

|

Vol. 35, nr 4

769-774

EN

The properties of sodium nitrite introduced in porous glasses have been investigated. SEM graphs indicate existence of sodium nitrite inside glass pores. It has been shown that FTIR and Raman spectra are similar for bulk sodium nitrite and sodium nitrite embedded into porous glass. The nature of FTIR and Raman bands has been determined. The size-effect of sodium nitride introduced into porous glass was observed on the basis of dielectric measurements.

16

Application of modified porous glasses Al2O3 for hydrocarbon contamination sorption

Procyk B., Rogowska-Kwas R., Reben M., Lisiecki M., Macuda J., Dorosz D.

Optica Applicata

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2005

|

Vol. 35, nr 4

775-781

EN

Tests on glass texture were made in order to establish the size of porous space in modified glasses Al2O3 from the system Na2O-B2O3-SiO2 after extraction of dissolved boron phase during chemical treatment. A difference was observed in the size and volume of mezo- and micropores in 0.6% and 0.3% Al2O3 glasses depending on temperature of heating. Accounting for the difference of glass structure attempts were made to use them for the selective sorption of hydrocarbons dissolved in water. It follows from the obtained results that differences in hydrocarbon removal are as much as tens of percent. The efficiency of removal is conditioned by the type of glass and grain size of glass applied for sorption.

17

Redukcja zanieczyszczeń węglowodorowych ze środowiska wodnego przy wykorzystaniu szkła porowatego

Macuda J., Procyk B., Rogowska-Kwas R., Zawisza L.

Wiertnictwo, Nafta, Gaz

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2004

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R. 21/1

239-245

PL

Substancje ropopochodne ze względu na swoje właściwości są bardzo szkodliwe dla środowiska, zwłaszcza gruntowo-wodnego. W przypadku wystąpienia awarii połączonej z niekontrolowanym wyciekiem do środowiska, część węglowodorów udaje się usunąć, ale zdecydowana większość infiltruje do gruntu, a następnie do wód podziemnych i powierzchniowych. Powodują one zmiany organoleptyczne wody, działają toksycznie na faunę i florę, kumulują się w tkankach organizmów żywych oraz stwarzają duże trudności przy uzdatnianiu wody. W artykule przedstawiono właściwości fizykochemiczne modyfikowanych szkieł porowatych z układu Na2O-B2O3-SiO3 oraz wyniki badań ich wykorzystania do usuwania węglowodorów ze środowiska wodnego. Na podstawie uzyskanej redukcji zanieczyszczeń w próbach laboratoryjnych można stwierdzić, że szkła porowate mogą być stosowane jako adsorbenty i wykorzystywane do likwidacji zanieczyszczeń węglowodorowych z wód podziemnych i powierzchniowych.

EN

Owing to their properties, oil products are very noxious for the environment, soil and water in particular. In the case of a break-down accompanied by an uncontrollable seepage to the environment, part of hydrocarbons can by removed, but most of them infiltrate the soil, ground- and surface waters. This results in organoleptic changes of water, toxication of flora and fauna and accumulation in the tissues of living organisms. Besides, such situations create serious problems with water treatment. Physicochemical properties of modified porous glasses Na2O-B2O3-SiO2 are presented and the results of their application to the removal of hydrocarbons from the water environment are discussed. It can be stated from the laboratory results of contamination reduction that porous glasses can be used as adsorbents for fighting hydrocarbon contaminations in ground- and surface waters.

18

Szkła porowate w procesie filtracji piwa.

Środa M., Szumera M., Wodnicka K.

Szkło i Ceramika

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2003

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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.

19

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

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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.

20

Sintering of optical porous glasses

Antropova T. V., Drozdova I. A.

Optica Applicata

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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.