TY  - JOUR
AU  - Bosnar, Sanja
AU  - Rac, Vladislav
AU  - Stošić, Dušan
AU  - Travert, Arnaud
AU  - Postole, Georgeta
AU  - Auroux, Aline
AU  - Škapin, Srečo
AU  - Damjanović-Vasilić, Ljiljana
AU  - Bronić, Josip
AU  - Du, Xuesen
AU  - Marković, Smilja
AU  - Pavlović, Vladimir
AU  - Rakić, Vesna
PY  - 2021
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5961
AB  - Dual templating approach, using hexadecyltrimethylammonium bromide (CTAB), was employed in an attempt to synthesize hierarchical ZSM-5 zeolite. Amount of mesoporogen and the duration of aging of the precursor were varied. Majority of the synthesis routes resulted in phase separation, yielding separate ZSM-5 and amorphous mesoporous material. The relative amounts of the two phases were dependent on the CTAB amount ratio and also significantly on the duration of precursor aging before CTAB addition. One particular combination of the two factors led to the formation of a homogeneous hierarchical form of ZSM-5 with leafy morphology, consisting of intergrown thin crystalline sheets which formed flower-like structures. The hierarchical ZSM-5 possessed significant microporous (≈95 m2/g) and highly developed mesoporous surface (≈470 m2/g), with a relatively broad distribution of mesopore sizes (<20 nm). The acidity of all samples was studied in detail. Isothermal microcalorimetry/volumetry of ammonia adsorption provided quantitative data on the number and distribution of strength of acidic sites. In situ FTIR of pyridine and collidine adsorption was used to quantify Brønsted and Lewis acid sites, and to provide information on their location - in the micropores or mesopores/external surface. The hierarchical ZSM-5 possessed both Lewis and Brønsted acidity, with Brønsted sites located mainly in the micropores. All samples were fully characterized using XRD, low temperature nitrogen adsorption, FESEM and EDS. The synthetic route used for obtaining the ZSM-5 zeolite with flower-like morphology is a simple strategy for preparing hierarchical ZSM-5 forms targeting enhanced diffusivity and accessibility of catalytically active sites.
PB  - Elsevier B.V.
T2  - Microporous and Mesoporous Materials
T1  - Overcoming phase separation in dual templating: A homogeneous hierarchical ZSM-5 zeolite with flower-like morphology, synthesis and in-depth acidity study
SP  - 111534
VL  - 329
DO  - 10.1016/j.micromeso.2021.111534
ER  - 

@article{
author = "Bosnar, Sanja and Rac, Vladislav and Stošić, Dušan and Travert, Arnaud and Postole, Georgeta and Auroux, Aline and Škapin, Srečo and Damjanović-Vasilić, Ljiljana and Bronić, Josip and Du, Xuesen and Marković, Smilja and Pavlović, Vladimir and Rakić, Vesna",
year = "2021",
abstract = "Dual templating approach, using hexadecyltrimethylammonium bromide (CTAB), was employed in an attempt to synthesize hierarchical ZSM-5 zeolite. Amount of mesoporogen and the duration of aging of the precursor were varied. Majority of the synthesis routes resulted in phase separation, yielding separate ZSM-5 and amorphous mesoporous material. The relative amounts of the two phases were dependent on the CTAB amount ratio and also significantly on the duration of precursor aging before CTAB addition. One particular combination of the two factors led to the formation of a homogeneous hierarchical form of ZSM-5 with leafy morphology, consisting of intergrown thin crystalline sheets which formed flower-like structures. The hierarchical ZSM-5 possessed significant microporous (≈95 m2/g) and highly developed mesoporous surface (≈470 m2/g), with a relatively broad distribution of mesopore sizes (<20 nm). The acidity of all samples was studied in detail. Isothermal microcalorimetry/volumetry of ammonia adsorption provided quantitative data on the number and distribution of strength of acidic sites. In situ FTIR of pyridine and collidine adsorption was used to quantify Brønsted and Lewis acid sites, and to provide information on their location - in the micropores or mesopores/external surface. The hierarchical ZSM-5 possessed both Lewis and Brønsted acidity, with Brønsted sites located mainly in the micropores. All samples were fully characterized using XRD, low temperature nitrogen adsorption, FESEM and EDS. The synthetic route used for obtaining the ZSM-5 zeolite with flower-like morphology is a simple strategy for preparing hierarchical ZSM-5 forms targeting enhanced diffusivity and accessibility of catalytically active sites.",
publisher = "Elsevier B.V.",
journal = "Microporous and Mesoporous Materials",
title = "Overcoming phase separation in dual templating: A homogeneous hierarchical ZSM-5 zeolite with flower-like morphology, synthesis and in-depth acidity study",
pages = "111534",
volume = "329",
doi = "10.1016/j.micromeso.2021.111534"
}

Bosnar, S., Rac, V., Stošić, D., Travert, A., Postole, G., Auroux, A., Škapin, S., Damjanović-Vasilić, L., Bronić, J., Du, X., Marković, S., Pavlović, V.,& Rakić, V.. (2021). Overcoming phase separation in dual templating: A homogeneous hierarchical ZSM-5 zeolite with flower-like morphology, synthesis and in-depth acidity study. in Microporous and Mesoporous Materials
Elsevier B.V.., 329, 111534.
https://doi.org/10.1016/j.micromeso.2021.111534

Bosnar S, Rac V, Stošić D, Travert A, Postole G, Auroux A, Škapin S, Damjanović-Vasilić L, Bronić J, Du X, Marković S, Pavlović V, Rakić V. Overcoming phase separation in dual templating: A homogeneous hierarchical ZSM-5 zeolite with flower-like morphology, synthesis and in-depth acidity study. in Microporous and Mesoporous Materials. 2021;329:111534.
doi:10.1016/j.micromeso.2021.111534 .

Bosnar, Sanja, Rac, Vladislav, Stošić, Dušan, Travert, Arnaud, Postole, Georgeta, Auroux, Aline, Škapin, Srečo, Damjanović-Vasilić, Ljiljana, Bronić, Josip, Du, Xuesen, Marković, Smilja, Pavlović, Vladimir, Rakić, Vesna, "Overcoming phase separation in dual templating: A homogeneous hierarchical ZSM-5 zeolite with flower-like morphology, synthesis and in-depth acidity study" in Microporous and Mesoporous Materials, 329 (2021):111534,
https://doi.org/10.1016/j.micromeso.2021.111534 . .

TY  - JOUR
AU  - Vu Tung Lam Tran
AU  - Gelin, Patrick
AU  - Ferronato, Corinne
AU  - Mascunan, Pascale
AU  - Rac, Vladislav
AU  - Chovelon, Jean-Marc
AU  - Postole, Georgeta
PY  - 2019
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5059
AB  - Commercial activated carbons (ACs) have been studied in dynamic adsorption of octamethylcyclotetrasiloxane (D4) in both dry and wet conditions. 1000 ppm (v/ v) D4 with N-2 as carrier gas and relative humidity (RH) up to 70% were used. Samples were characterized by physicochemical techniques such as N-2 and H2O adsorption/desorption at -196 and 20 degrees C, respectively, XPS, Boehm titration, chemical and elemental analysis, thermogravimetric measurements. No correlation between adsorption capacity in dry conditions and textural properties could be established. In wet conditions, the presence of hydrophilic sites preferentially adsorbing H2O strongly decreases the ability of ACs to adsorb D4. The regenerability by thermal treatment after D4 adsorption in dry conditions was also addressed and followed by gas chromatography and in situ DRIFTS. The D4 polymerization into polysiloxanolate/PDMS was found to proceed on ACs containing alkali metals (K, Na) as revealed by the observed release of their decomposition products during the thermodesorption treatment. This property is detrimental to the regenerability of the AC by blockage of its porosity. The eventual formation of polysiloxanalolate type species during the adsorption could also be responsible for limiting the D4 uptake by partial blockage of the AC porosity.
PB  - Elsevier Science Sa, Lausanne
T2  - Chemical Engineering Journal
T1  - Siloxane adsorption on activated carbons: Role of the surface chemistry on sorption properties in humid atmosphere and regenerability issues
EP  - 832
SP  - 821
VL  - 371
DO  - 10.1016/j.cej.2019.04.087
ER  - 

@article{
author = "Vu Tung Lam Tran and Gelin, Patrick and Ferronato, Corinne and Mascunan, Pascale and Rac, Vladislav and Chovelon, Jean-Marc and Postole, Georgeta",
year = "2019",
abstract = "Commercial activated carbons (ACs) have been studied in dynamic adsorption of octamethylcyclotetrasiloxane (D4) in both dry and wet conditions. 1000 ppm (v/ v) D4 with N-2 as carrier gas and relative humidity (RH) up to 70% were used. Samples were characterized by physicochemical techniques such as N-2 and H2O adsorption/desorption at -196 and 20 degrees C, respectively, XPS, Boehm titration, chemical and elemental analysis, thermogravimetric measurements. No correlation between adsorption capacity in dry conditions and textural properties could be established. In wet conditions, the presence of hydrophilic sites preferentially adsorbing H2O strongly decreases the ability of ACs to adsorb D4. The regenerability by thermal treatment after D4 adsorption in dry conditions was also addressed and followed by gas chromatography and in situ DRIFTS. The D4 polymerization into polysiloxanolate/PDMS was found to proceed on ACs containing alkali metals (K, Na) as revealed by the observed release of their decomposition products during the thermodesorption treatment. This property is detrimental to the regenerability of the AC by blockage of its porosity. The eventual formation of polysiloxanalolate type species during the adsorption could also be responsible for limiting the D4 uptake by partial blockage of the AC porosity.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Chemical Engineering Journal",
title = "Siloxane adsorption on activated carbons: Role of the surface chemistry on sorption properties in humid atmosphere and regenerability issues",
pages = "832-821",
volume = "371",
doi = "10.1016/j.cej.2019.04.087"
}

Vu Tung Lam Tran, Gelin, P., Ferronato, C., Mascunan, P., Rac, V., Chovelon, J.,& Postole, G.. (2019). Siloxane adsorption on activated carbons: Role of the surface chemistry on sorption properties in humid atmosphere and regenerability issues. in Chemical Engineering Journal
Elsevier Science Sa, Lausanne., 371, 821-832.
https://doi.org/10.1016/j.cej.2019.04.087

Vu Tung Lam Tran, Gelin P, Ferronato C, Mascunan P, Rac V, Chovelon J, Postole G. Siloxane adsorption on activated carbons: Role of the surface chemistry on sorption properties in humid atmosphere and regenerability issues. in Chemical Engineering Journal. 2019;371:821-832.
doi:10.1016/j.cej.2019.04.087 .

Vu Tung Lam Tran, Gelin, Patrick, Ferronato, Corinne, Mascunan, Pascale, Rac, Vladislav, Chovelon, Jean-Marc, Postole, Georgeta, "Siloxane adsorption on activated carbons: Role of the surface chemistry on sorption properties in humid atmosphere and regenerability issues" in Chemical Engineering Journal, 371 (2019):821-832,
https://doi.org/10.1016/j.cej.2019.04.087 . .

TY  - JOUR
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Rusmirović, Jelena D.
AU  - Postole, Georgeta
AU  - Marinković, Aleksandar
AU  - Radić, Danka
AU  - Rakić, Vesna
AU  - Pavlović, Vladimir
AU  - Auroux, Aline
PY  - 2017
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4477
AB  - In this paper, synthesis of porous wollastonite-based ceramics was reported. Ceramic precursor, methylhydrocyclosiloxane, together with micro-sized CaCO3, was used as starting material. After 20 min of ultrasound treatment, and calcination at 250 degrees C for 30 min, yeast as a pore-forming agent was added to the as-obtained powders. Sintering regime was set up based on the results obtained by differential thermal analysis. Prepared mixture was pressed into pallets and sintered at 900 degrees C for 1 h. After the sintering regime, porous wollastonite-based ceramics was obtained. The phase composition of the sintered samples as well as microstructures was analyzed by X-ray diffraction method and SEM. In a batch test, the influence of pH, contact time and initial ion concentration on adsorption efficiency of As+5, Cr+6, and phosphate ions on synthesized wollastonite-based ceramics were studied. Time-dependent adsorption was best described by pseudo-second-order kinetic model and Weber-Morris model that predicted intra-particle diffusion as a rate-controlling step of overall process. High adsorption capacities 39.97, 21.87, and 15.29 mgg(-1) were obtained for As+5, Cr+6, and phosphate ions, respectively.
PB  - Međunarodni Institut za nauku o sinterovanju, Beograd
T2  - Science of Sintering
T1  - Formation of Porous Wollastonite-based Ceramics after Sintering With Yeast as the Pore-forming Agent
EP  - 246
IS  - 3
SP  - 235
VL  - 49
DO  - 10.2298/SOS1703235O
ER  - 

@article{
author = "Obradović, Nina and Filipović, Suzana and Rusmirović, Jelena D. and Postole, Georgeta and Marinković, Aleksandar and Radić, Danka and Rakić, Vesna and Pavlović, Vladimir and Auroux, Aline",
year = "2017",
abstract = "In this paper, synthesis of porous wollastonite-based ceramics was reported. Ceramic precursor, methylhydrocyclosiloxane, together with micro-sized CaCO3, was used as starting material. After 20 min of ultrasound treatment, and calcination at 250 degrees C for 30 min, yeast as a pore-forming agent was added to the as-obtained powders. Sintering regime was set up based on the results obtained by differential thermal analysis. Prepared mixture was pressed into pallets and sintered at 900 degrees C for 1 h. After the sintering regime, porous wollastonite-based ceramics was obtained. The phase composition of the sintered samples as well as microstructures was analyzed by X-ray diffraction method and SEM. In a batch test, the influence of pH, contact time and initial ion concentration on adsorption efficiency of As+5, Cr+6, and phosphate ions on synthesized wollastonite-based ceramics were studied. Time-dependent adsorption was best described by pseudo-second-order kinetic model and Weber-Morris model that predicted intra-particle diffusion as a rate-controlling step of overall process. High adsorption capacities 39.97, 21.87, and 15.29 mgg(-1) were obtained for As+5, Cr+6, and phosphate ions, respectively.",
publisher = "Međunarodni Institut za nauku o sinterovanju, Beograd",
journal = "Science of Sintering",
title = "Formation of Porous Wollastonite-based Ceramics after Sintering With Yeast as the Pore-forming Agent",
pages = "246-235",
number = "3",
volume = "49",
doi = "10.2298/SOS1703235O"
}

Obradović, N., Filipović, S., Rusmirović, J. D., Postole, G., Marinković, A., Radić, D., Rakić, V., Pavlović, V.,& Auroux, A.. (2017). Formation of Porous Wollastonite-based Ceramics after Sintering With Yeast as the Pore-forming Agent. in Science of Sintering
Međunarodni Institut za nauku o sinterovanju, Beograd., 49(3), 235-246.
https://doi.org/10.2298/SOS1703235O

Obradović N, Filipović S, Rusmirović JD, Postole G, Marinković A, Radić D, Rakić V, Pavlović V, Auroux A. Formation of Porous Wollastonite-based Ceramics after Sintering With Yeast as the Pore-forming Agent. in Science of Sintering. 2017;49(3):235-246.
doi:10.2298/SOS1703235O .

Obradović, Nina, Filipović, Suzana, Rusmirović, Jelena D., Postole, Georgeta, Marinković, Aleksandar, Radić, Danka, Rakić, Vesna, Pavlović, Vladimir, Auroux, Aline, "Formation of Porous Wollastonite-based Ceramics after Sintering With Yeast as the Pore-forming Agent" in Science of Sintering, 49, no. 3 (2017):235-246,
https://doi.org/10.2298/SOS1703235O . .