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1

On the Influence of Chemical Modification of Silica on Its Porous Structure under Solvothermal Conditions

Sidorchuk V. V., Skubiszewska-Zięba J., Charmas B., Leboda R.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 1-2

183-190

EN

Changes of porous structure of silica gels (aerosilogels) were studied during their chemical modification under various conditions, i.e. solvothermal at high temperature and pressure of reagents as well as in common treatment with substances of different chemical character without high pressure. Necessity of taking into account the effects of transfer of silica mass during its modification under the conditions of high pressure of modifying agent (organothermal treatment) on its porous structure parameters was pointed to.

2

Interaction of Nanooxides with Poly(vinyl alcohol)

Gun'ko V., Zarko V., Andriyko L., Leboda R., Skubiszewska-Zięba J., Janusz W.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 3

411-424

EN

Interaction of silica, alumina/silica and titania/silica nanooxideswith poly(vinyl alcohol) was investigated in gaseous and aqueous media using infrared spectroscopy, adsorption, AFM and photon correlation spectroscopy methods. Formation of PVA monolayer on oxide nanoparticles leads to relatively small changes in morphological and textural characteristics of the materials. The characteristics of interfacial water/PVA layer, particle size distribution and Cd(II) adsorption depend on surface content of alumina or titania affecting amounts of Brönsted and Lewis acid sites. Arelativelyweak influence of various pretreatments on the structural characteristics of the materials depicts the stability of PVA/nanooxide composites as dry powders and aqueous dispersions.

3

Preparatyka sferycznych adsorbentów węglowych na bazie żywic jonowymiennych

Grzegorczyk W., Skubiszewska-Zięba J., Leboda R.

Przemysł Chemiczny

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2006

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T. 85, nr 8-9

720-722

PL

Przeprowadzono badania procesu karbonizacji i aktywacji żywicy jonowymiennej w celu otrzymywania porowatych materiałów węglowych. Obróbce poddano żywicę Amberlite ICR-84 w formie wodorowej, sodowej i wapniowej. Najkorzystniejszą formą prekursora materiału o rozwiniętej strukturze porowatej była żywica obsadzona jonami wapnia. Rozwinięcie struktury zależało od ładunku jonów metalu w wyjściowym materiale żywicy.

EN

A 0.2–08-mm H-, Na- or Ca-form Amberlite ICR-84 was dried at 383 K and pyrolyzed over 383–700 K at 5 K/min and then over 700–1000 K at 10 or 14 K/min in He or N atm. The chars were partly gasified with 20 mol% H2O + N2 for 25 min. Ca was removed with 3M HCl. Up to 400 K, each resin was equally thermostable. Up to 700 K, the H- and the Na-forms lost 70% and the 0.5%Ca and the 5.9%Ca forms lost 65 and 20% in wt. The Ca-form was most effective as a precursor to a micro and mesoporous material, sp. surface 170–185 m2/g, pore size ca. 2 ml/g. The porous structure was related to the metal ion charge and to the ramp rate. Particle size of the starting resin was irrelevant.

4

Wpływ wymrażania próbek węgli aktywnych z wodą na ich strukturę porowatą

Skubiszewska-Zięba J., Leboda R., Gunko V.M., Palijczuk D., Ziętek S.

Przemysł Chemiczny

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2004

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T. 83, nr 2

79-83

PL

Badano wpływ zamrażania, w temperaturze ciekłego azotu, czterech próbek węgli aktywnych (SB£T oraz Vp w zakresie odpowiednio 877-2164 m2/g oraz 0,445-1,044 cm3/g), zawierających różne ilości wody, na ich strukturę porowatą. Z danych niskotemperaturowej adsorpcji/desorpcji azotu wyznaczono: powierzchnię właściwą adsorbentów (SBET), całkowitą sorpcyjną objętość porów (Vp), powierzchnię mezoporów (SK), powierzchnię i objętość mikroporów (SDS, VDS), średnią wielkość połowy szerokości szczeliny mikroporów (XDS), wymiar fraktalny (DAJ) i funkcje rozkładu porów. Stwierdzono, że zamrażanie próbek węgli aktywnych powoduje wzrost od kilku do kilkunastu procent objętości porów i wielkości powierzchni właściwej oraz zmianę innych charakterystyk. Modyfikacja węgla aktywnego w ciekłym azocie znacznie poprawia jego efektywność w procesie dynamicznej adsorpcji par fert-butylobenzenu.

EN

(A) Air-borne H2O or (B) liq. H2O was sorbed on 4 microporous C (SBEr 877, 1351, 1873, and 2164 m2/g; porę vol., 0.445, 0.749, 1.037, and 1.044 cms/g; particle s/ze 0.5-0.71 mm; (A) H2O sorbed, 10.25, 6.45, 8.55, and 4%), and the specimens were kept 2 h ał 77.4 K, heated to 20°C, dehydrated, and reheated at 473 K/1 pbar. The SBETand porę vol. rosę by (A) 4.4-7.2 and 5.2 -8.4; (B) 6.1-10.5 and 7.110.4%, resp. Freezing affected the proportions of micro and meso pores, the C becoming morę heterogeneous. As the micropore share rosę, the C became morę fractal. On the A-modified carbon, tert-Bu benzene was adsorbed morę effectively.

5

Badanie adsorpcji dynamicznej par tert-butylobenzenu na komercyjnych węglach aktywnych D43/1 i D55/2 pod kątem zastosowania ich w sprzęcie ochrony układu oddechowego

Palijczuk D, Kowalczyk P., Pietrzykowski M., Ziętek S., Ziętek M., Szmigielski R., Leboda R.

Przemysł Chemiczny

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2002

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T. 81, nr 11

716-721

6

Sorpcja wybranych anionów nieorganicznych na węglu aktywnym

Gierak A., Leboda R.

Ochrona Środowiska

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2001

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nr 2

9-14

EN

Carbon sorbents differing in surface properties were used for the adsorption of inorganic onions (Cl [-], Br [-], J [-], NO2 [-], NO3 [-], SCN [-], SO4 [2-], C2O4 [2-], CrO4 [2-]) from aqueous solutions. Making use of the solid phase extraction method, single onions, as well as a mixture of those, were investigated for the efficiency of concentration on the carbon sorbent. The initial carbon material (made of plum stones) was purchased from GRYFSKAND (Hajnówka, Poland). In order to change their porous structures, as well as the amount and type of the polar groups on their surfaces, the sorbents were processed by a variety of physicochemical methods. Anion concentrations were measured by ion chromatography and UV-VIS spectroscopy. Analysis of sorption isotherms for inorganic ions on modified active carbons suggests that sorption process was affected by the following factors: the type of the onion sorbed, the nature of the carbon sorbent surface, and the presence of other ions in the solution under test.

7

Sorpcja jonów wybranych metali ciężkich na węglu aktywnym

Gierak A., Leboda R.

Ochrona Środowiska

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2001

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nr 1

9-15

EN

Investigated was the sorption of heavy metals (Fe(III), Pb(II), Ni(II), Co(II) Cd(II) and Zn(II)) from aqueous solutions on carbon adsorbents which varied in surface properties. To examine the efficiency of single metal concentration on the carbon adsorbent use was made of the solid phase extraction technique. The initial carbon material was purchased from GRYFSKAND (Hajnówka, Poland). The adsorbents were processed by a variety physicochemical methods in order to change the porous structure, as well as the amount and type of the polar groups on the surface. Metal concentrations were measured by atomic absorption spectroscopy. Analysis of the sorption isotherms for heavy metals on modified active carbons suggests that the sorption process was affected by the type of the metal sorbed, by the pH of the solution, by the nature of the adsorbent surface and by the presence of other ions in aqueous solution.

8

Chromatographic properties of carbon adsorbents prepared by the high-temperature treatment of polish industrial active carbon from plum stones

Leboda R., Skubiszewska-Zięba J., Marciniak M., Czechowski F.

Chemia Analityczna

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2000

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Vol. 45, No. 3

341-351

EN

The influence of high-temperature (2400°C) treatment of two active carbons from plum stones differing in mesoporosity degree on their surface properties was studied. There were determined the following characteristics of the prepared adsorbepts: specific surface area, total porę volume, micropore volume, average pore size, crystallographic structure parameters, adsorption heats of benzene, n-hexane and chloroform. Using gas chromatography, there were made separations of saturated aqueous solutions of aliphatic and aromatic hydrocarbons as well as halogen derivatives, alcohols, ketones and others. Suitable experiments were carried out using the commercial carbon adsorbent Carbo-pack C, produced by Supelco, for comparison. The obtained adsorbents had quite advan-tageous surface parameters to be applied in chromatography.

PL

Badano wpływ wysokotemperaturowej (2400°C) obróbki dwóch węgli aktywnych z pestek śliwek, różniących się stopniem mezoporowatości, na ich właściwości powierzchniowe. Wyznaczono następujące charakterystyki spreparowanych adsorbentów: wielkość powierzchni właściwej, ogólną objętość porów, objętość mikroporów, średni rozmiar porów, strukturę krystalograficzną, ciepła adsorpcji benzenu, n-heksanu i chloroformu, jak również przeprowadzono rozdziały metodą chromatografii gazowej nasyconych wodnych roztworów mieszanin węglowodorów: alifatycznych, aromatycznych, chlorowcopochodnych, alkoholi, ketonów i innych. Dla porównania wykonano odpowiednie eksperymenty na handlowym adsorbencie węglowym Carbopack C, firmy Supelco. Uzyskano adsorbenty o dość korzystnych parametrach powierzchniowych do wykorzystania ich w chromatografii.

9

Pathways for Decomposition of Phenylethanol Bound to Silica Surface

Gun'ko V., Leboda R., Pokrovsky V.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 8

1345-1356

EN

Thermal desorption and decomposition of 2-phenylethanol bound to the silica gel surface were studied after its partial carbonization at 400 C and washing off pitch compounds not bound chemically to the surface. Various possible unimolecular and bimolecular reactions were discussed, based on investigations by temperature-programmed desorption (TPD) mass spectrometry and theoretical methods.

10

Analiza azotanów i bromianów powstających podczas dezynsekcji wody ozonem

Gierak A., Leboda R.

Ochrona Środowiska

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1999

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nr 4

13-16

EN

When the surface water to be treated contains bromides and ammonium salts, ozonation will stimulate the formation of bromates, nitrites and nitrates, which have been identified as potential cancerogenic species. The admissible concentration of nitrates defined in Polish Standards is 10 gN/m (which corresponds to ca. 44 gNO3/m3 ). In Germany, the admissible concentration of nitrites must not exceed 0.1 gN/m3 . In Poland, the admissible concentration ofbromates has not been established yet. The maximal admissible concentrations of bromates in drinking water recommended by US EPA and WHO range between 10 and 50mgBr03 /m3. Moreover, it is postulated that, in future, these levels should be decreased to 5 mg/m3 , as soon as appropriate methods have been developed to enable determination of such low bromate levels. The objective of the present study was to discuss the problems that have to be tackled when determining bromate and nitrate concentrations in municipal water by high-performance ion-exchange chromatograpliy (IC-HPLC) or other teclmiques. Our investigations fiave sliown that direct determinations of nitrates and bromates are feasible at concentrations of 2 gNO3/m3 and over 0.2 gBrO3/m3, respectively.

11

Investigations of usefulness of transcarpathian zeolites in trace analysis of waters. Application of mordenite for the preconcentration of trace amounts of copper and cadmium

Vasylechko V. O., Lebedynets L. O., Gryshchouk G. V., Leboda R., Skubiszewska-Zięba J.

Chemia Analityczna

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1999

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Vol. 44, No. 6

1013-1024

EN

The surface properties of the Ukrainian Transcarpathian mordenite from West Ukraine ( containing 90% of zeolite) have been investigated in terms of its applicability for. the isolation and co11cel1tration of trace amounts of Cu(II) and Cd(II) from water. The solid phase extraction has been carried out and the optimum conditions established. The infuence of several factors on the adsorption and desorptio11 of Cu(II) and Cd(II) ions have been studied. These factors were following: temperature of a preliminary treatment of mordenite, presence of foreign ions in the solution, rate of solution introducing into the column, temperature and pH of the solution, and type of eluent used for the desorption. From the data of low temperature adsorption and desorption isotherms of nitrogen, the parameters of structure of the starting natural mordenite were calculated. The properties of starting mordenite were investigated by means of differential thermal analysis and desorption of water from the starting adsorbent and from adsorbent modified by heating at a temperature of 150°C, was studied with quasi-isothemaI method. Such a modification method was selected as it results in optimum properties for the isolation and the isolation and concentration of trace amounts of Cu(II) and Cd(II). Under optimum deserption conditions the effective extraction of coppel. and cadmium was 99.8 al1d 94% respectively.

PL

Stosując metodę ekstrakcji do fazy stałej badano właściwości powierzchniowe zakarpackiego mordenitu z zachodniej Ukrainy (zawierającego (90% zeolitu) pod kątem jego przydatności do izolowania i zatężania śladowych ilości Cu(II) i Cd(II) zawartych w wodach metodą solid-phase-extraction. Ustalono optymalne warunki przeprowadzania takiego procesu. Zbadano wpływ następujących czynników na efektywność procesu adsorpcji i desorpcji jonów Cu(II) i Cd(II): temperatury wstępnej obróbki mordenitu, obecności w roztworze obcych jonów, szybkości podawania na kolumnę roztworów oraz ich temperatury i pH, rodzaju eluenta użytego do desorpcji Cu(II) i Cd(II). Z danych niskotemperaturowych izoterm adsorpcji-desorpcji azotu, obliczono parametry struktury porowatej wyjściowego mordenitu. Metodą różnicowej analizy termicznej badano właściwości wyjściowego mordenitu, zaś metodą quasi-isothermiczną- desorpcję wody z wyjściowego adsorbentu oraz wygrzewanego w temp. 150°C, w której osiągał opty-malne właściwości do izolowania i wzbogacania śladów Cu(II) i Cd(II). Przy zachowa-niu optymalnych warunków procesu desorpcji, efektywność ekstrakcji miedzi i kadmu wynosiła odpowiednio 99.8 i 94 %.

12

Badania nad przydatnością zakarpackiego klinoptylolitu do adsorbcji chloroformu z roztworów wodnych

Vasylechko V.O., Lebedynets L.O., Gryshchouk G.V., Leboda R., Skubiszewska-Zięba J.

Ochrona Środowiska

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1998

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nr 3

27-30

EN

The objective of the study was to determine the sorbing capacity of the transcarpathian clinophylolite ( Ukraine ) when applied to chloroform separation from aqueous solutions. Analyses and measurements included the chemical parameters and porosity of the mineral, as well as the effect of processing temperature, grain size distribution and pH ( of the agueous solution ) on the sorbing properties with respect to water and chloroform.The efficiency of chloroform sorption from the agueous solution ranged from 97 to 99%.This is an indication that the clinoptylolite has a great potential for being effectively used as a sorbend in the concentration of chloroform occuring in agueous solutions.The properties of the clinoptylolite make it applicable not only to analytical procedures,but also to water treatment.

13

Badania nad przydatnością klinoptylolitu do adsorpcji jonów Hg(II),Cr(III) i Ni(II) z roztworów wodnych

Gomonaj V.I., Golub N.P., Szekeresh K.Y., Leboda R., Skubiszewska-Zięba J.

Ochrona Środowiska

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1998

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nr 4

3-6

EN

The objective of the study was to assess the usefulness of the Transcarpatien zeolite-clinoptylolite ( Sokirnica,Ukraine) when applied to the removal of Hg(II),Ni(II) and Cr(III) ions from aqueous solutions.The experiments were carried out with three types of clinoptylolite samples-natural,after thermal processing ( 300 and 500.o C),and after chemical modification (with NH4Cl or HCl).Thus,natural clinoptylolote adr clinoptylolite modifical with 3N NH4Cl were found to have a high sorbing capacity.Maximum adsorption of Hg(II) ions (amounting to 4.7 mg/g was achieved within two hours.The adsorption of Ni(II) ions was alamost complete wilin on hour.The efficiency of Cr(III), ion adsorption amounted to 70%. These data indicate that the investigated clynoptilolite has a potential for being effectively used in water treatment for drunking purposes.Ist properties make in also applicable to the removal of heavy metals from wasterwater. A low initial concentrations of Ni(II) and Cr(III), a good treatment effect conbe achieved within a comparatively short time of contact,ar a result of filtration on the clinoptylolite bed.