TY  - JOUR
AU  - Milovanović, Željka
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Radovanović, Željko
AU  - Cvetković, Slobodan
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6578
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7169
AB  - The sepiolite/ZrO2 composites were prepared by sepiolite (Sep) modification with zirconium propoxide in toluene at room temperature for 24 h (Sep–ZrI) or 95 °C for 4 h (sample Sep–ZrII). The efficiency of the obtained composites for the removal of phosphate from aqueous solutions at initial pH = 4 and pH = 8 was investigated. Characterization of the samples shows that synthesis at a higher temperature for a shorter time provides a slightly higher content of amorphous Zr phase, which is deposited on the sepiolite fibers as a thin layer and agglomerated nanoparticles. Compared to Sep, the composites have a lower point of zero charge and higher specific surface area and pore volume. The adsorption kinetics follow the pseudo second-order model. The adsorption capacities of the composites are approximately the same at both initial pH and higher at initial pH = 4 than at pH = 8. The XPS and ATR-FTIR of Sep–ZrI before and after adsorption identifies the formation of inner-sphere complexes as the mechanism of phosphate adsorption. The slow release during desorption with NaOH solution confirms the strong bonds of the phosphates with the surface of the composites.
PB  - MDPI
T2  - Water
T1  - The Removal of Phosphate from Aqueous Solutions by Sepiolite/ZrO2 Composites: Adsorption Behavior and Mechanism
VL  - 15
IS  - 13
SP  - 2376
DO  - 10.3390/w15132376
ER  - 

@article{
author = "Milovanović, Željka and Lazarević, Slavica and Janković-Častvan, Ivona and Radovanović, Željko and Cvetković, Slobodan and Janaćković, Đorđe and Petrović, Rada",
year = "2023",
abstract = "The sepiolite/ZrO2 composites were prepared by sepiolite (Sep) modification with zirconium propoxide in toluene at room temperature for 24 h (Sep–ZrI) or 95 °C for 4 h (sample Sep–ZrII). The efficiency of the obtained composites for the removal of phosphate from aqueous solutions at initial pH = 4 and pH = 8 was investigated. Characterization of the samples shows that synthesis at a higher temperature for a shorter time provides a slightly higher content of amorphous Zr phase, which is deposited on the sepiolite fibers as a thin layer and agglomerated nanoparticles. Compared to Sep, the composites have a lower point of zero charge and higher specific surface area and pore volume. The adsorption kinetics follow the pseudo second-order model. The adsorption capacities of the composites are approximately the same at both initial pH and higher at initial pH = 4 than at pH = 8. The XPS and ATR-FTIR of Sep–ZrI before and after adsorption identifies the formation of inner-sphere complexes as the mechanism of phosphate adsorption. The slow release during desorption with NaOH solution confirms the strong bonds of the phosphates with the surface of the composites.",
publisher = "MDPI",
journal = "Water",
title = "The Removal of Phosphate from Aqueous Solutions by Sepiolite/ZrO2 Composites: Adsorption Behavior and Mechanism",
volume = "15",
number = "13",
pages = "2376",
doi = "10.3390/w15132376"
}

Milovanović, Ž., Lazarević, S., Janković-Častvan, I., Radovanović, Ž., Cvetković, S., Janaćković, Đ.,& Petrović, R.. (2023). The Removal of Phosphate from Aqueous Solutions by Sepiolite/ZrO2 Composites: Adsorption Behavior and Mechanism. in Water
MDPI., 15(13), 2376.
https://doi.org/10.3390/w15132376

Milovanović Ž, Lazarević S, Janković-Častvan I, Radovanović Ž, Cvetković S, Janaćković Đ, Petrović R. The Removal of Phosphate from Aqueous Solutions by Sepiolite/ZrO2 Composites: Adsorption Behavior and Mechanism. in Water. 2023;15(13):2376.
doi:10.3390/w15132376 .

Milovanović, Željka, Lazarević, Slavica, Janković-Častvan, Ivona, Radovanović, Željko, Cvetković, Slobodan, Janaćković, Đorđe, Petrović, Rada, "The Removal of Phosphate from Aqueous Solutions by Sepiolite/ZrO2 Composites: Adsorption Behavior and Mechanism" in Water, 15, no. 13 (2023):2376,
https://doi.org/10.3390/w15132376 . .

TY  - JOUR
AU  - Ugrinović, Vukašin
AU  - Panić, Vesna
AU  - Spasojević, Pavle
AU  - Šešlija, Sanja
AU  - Božić, Bojan
AU  - Petrović, Rada
AU  - Janaćković, Đorđe
AU  - Veljović, Đorđe
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5243
AB  - Hydrogels are promising materials for biomedical applications due to highly hydrated, porous, permeable structure with possibility to accommodate living cells, drugs, or bioactive factors. In this paper, we reported poly(methacrylic acid) (PMAA)/gelatin IPN hydrogels, synthesized by free-radical polymerization, with adjustable mechanical, structural, physicochemical, and biological characteristics. The influence of methacrylic acid (MAA), gelatin, and cross-linker in the precursor solution on hydrogels properties was investigated. The increasing concentration of MAA, gelatin, and cross-linker led to better mechanical properties, lower porosity, and water content. The compressive mechanical properties of hydrogels were significantly better in comparison to a single-network PMAA hydrogel, while the obtained compressive strength values up to 16 MPa were comparable with tough hydrogels. The increasing concentration of MAA and cross-linker reduced fatigue resistance and degradability, while the increase in gelatin content acted in the opposite way. Swelling tests in different pH conditions demonstrated strong pH-sensibility of the hydrogels, which was more pronounced as MAA concentration was higher, and gelatin and cross-linker concentrations were lower. In addition, the hydrogels strongly promoted the proliferation of human periodontal ligament stem cells and MRC-5 cells as assayed by MTT assay.
PB  - Wiley
T2  - Polymer Engineering and Science
T1  - Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid)
VL  - 62
SP  - 622
EP  - 636
DO  - 10.1002/pen.25870
ER  - 

@article{
author = "Ugrinović, Vukašin and Panić, Vesna and Spasojević, Pavle and Šešlija, Sanja and Božić, Bojan and Petrović, Rada and Janaćković, Đorđe and Veljović, Đorđe",
year = "2022",
abstract = "Hydrogels are promising materials for biomedical applications due to highly hydrated, porous, permeable structure with possibility to accommodate living cells, drugs, or bioactive factors. In this paper, we reported poly(methacrylic acid) (PMAA)/gelatin IPN hydrogels, synthesized by free-radical polymerization, with adjustable mechanical, structural, physicochemical, and biological characteristics. The influence of methacrylic acid (MAA), gelatin, and cross-linker in the precursor solution on hydrogels properties was investigated. The increasing concentration of MAA, gelatin, and cross-linker led to better mechanical properties, lower porosity, and water content. The compressive mechanical properties of hydrogels were significantly better in comparison to a single-network PMAA hydrogel, while the obtained compressive strength values up to 16 MPa were comparable with tough hydrogels. The increasing concentration of MAA and cross-linker reduced fatigue resistance and degradability, while the increase in gelatin content acted in the opposite way. Swelling tests in different pH conditions demonstrated strong pH-sensibility of the hydrogels, which was more pronounced as MAA concentration was higher, and gelatin and cross-linker concentrations were lower. In addition, the hydrogels strongly promoted the proliferation of human periodontal ligament stem cells and MRC-5 cells as assayed by MTT assay.",
publisher = "Wiley",
journal = "Polymer Engineering and Science",
title = "Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid)",
volume = "62",
pages = "622-636",
doi = "10.1002/pen.25870"
}

Ugrinović, V., Panić, V., Spasojević, P., Šešlija, S., Božić, B., Petrović, R., Janaćković, Đ.,& Veljović, Đ.. (2022). Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid). in Polymer Engineering and Science
Wiley., 62, 622-636.
https://doi.org/10.1002/pen.25870

Ugrinović V, Panić V, Spasojević P, Šešlija S, Božić B, Petrović R, Janaćković Đ, Veljović Đ. Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid). in Polymer Engineering and Science. 2022;62:622-636.
doi:10.1002/pen.25870 .

Ugrinović, Vukašin, Panić, Vesna, Spasojević, Pavle, Šešlija, Sanja, Božić, Bojan, Petrović, Rada, Janaćković, Đorđe, Veljović, Đorđe, "Strong and tough, pH sensible, interpenetrating network hydrogels based on gelatin and poly(methacrylic acid)" in Polymer Engineering and Science, 62 (2022):622-636,
https://doi.org/10.1002/pen.25870 . .

TY  - JOUR
AU  - Ugrinović, Vukašin
AU  - Panić, Vesna
AU  - Veljović, Đorđe
AU  - Spasojević, Pavle
AU  - Šešlija, Sanja
AU  - Janaćković, Đorđe
PY  - 2018
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2279
AB  - Goals. The goal of this study was a development of biocompatible composite hydrogels, structurally similar to native bone tissue, by incorporation of ~60 wt % of calcium hydroxyapatite (HA) into a matrix of hydrogels. Also, a possibility to control swelling kinetic and equilibrium swelling degree (SDeq) of hydrogels, by altering the degree of neutralization of the precursor (DN) was examined. Methods. Composite hydrogels, based on HA and poly(methacrylic acid) (PMAA), were synthesized by free-radical polymerization with different DN. Theoretical content of HA in synthesized composites was 60 wt %. Composites were synthesized by methods of dynamic mechanical analysis and scanning electron microscopy. SDeq and swelling kinetic were examined in distilled water and simulated body fluid. Results. Morphological observations revealed uniform distribution and strong bond of spherical HA particles within the polymer matrix. Swelling analyses demonstrated that SDeq is directly proportional to DN, while rheological examinations indicated inverse proportion between DN and storage modulus, but due to the HA particles inclusion, mechanical properties of composites were significantly better compared to monophasic PMAA hydrogels. Significance. Simple method of synthesis of composite hydrogels with high content of filler nanoparticles is presented. Incorporation of HA nanoparticles significantly improved mechanical properties of hydrogels, while at the same time was demonstrated a possibility to control swelling kinetic by influencing the DN.
AB  - Ciljevi - Cilj ove studije bio je razvoj biokompatibilnih kompozitnih hidrogelova, koji su slične strukture kao prirodno koštano tkivo, inkorporacijom ∼60 mas % kalcijum-hidroksiapatita (HA) u matricu hidro-gela. Takođe, ispitan je uticaj neutralizacije prekursora polimerne mreže na kinetiku bubrenja i ravnotežni stepen bubrenja (SDeq).Metode - Kompozitni hidrogelovi, sastavljeni od HA i poli(metakrilne kiseline) (PMAA), sintetisani su slobodno-radikalskom polimerizacijom, pri različitim stepenima neutralizacije prekursora (SN). Svi sintetisani kompoziti sadrže visok maseni udeo HA (~60 mas %). Kompoziti su okarakterisani metodama skenirajuće elektronske mikroskopije (SEM) i dinamičko-mehaničke analize (DMA). SDeq i kinetika bubrenja ispitivani su u destilovanoj vodi i simuliranoj telesnoj tečnosti (SBF). Rezultati - Morfološka ispitivanja pokazala su uniformnu raspodelu i dobru povezanost sferičnih čestica apatita sa polimernom matricom. Analiza procesa bubrenja pokazala je proporcionalnu zavisnost SN i SDeq kompozita. Reološka ispitivanja ukazala su na obrnuto proporcionalnu zavisnost između SN i vrednosti modula sačuvane energije, koji su iznosili 55130 Pa u slučaju potpune neutralizacije i 77480 Pa u slučaju 0% neutralizacije. Značaj - Predstavljena je jednostavna metoda za sintezu kompozitnih hidrogelova sa visokim masenim udelom nanočestica punioca. Inkorporacijom nanočestica HA postignuto je značajno poboljšanje mehaničkih svojstava hidrogelova, dok je istovremeno pokazano da je promenom SN moguće kontrolisati kinetiku bubrenja hidrogelova. .
PB  - Beograd : Savez inženjera i tehničara Srbije
T2  - Tehnika
T1  - Synthesis and properties of nano-hydroxyapatite/poly (methacrylic acid) composite hydrogels
T1  - Uticaj neutralizacije na svojstva poroznih hidrogelova na bazi hidroksiapatita i poli(metakrilne kiseline) sintetisanih slobodno-radikalskom polimerizacijom
VL  - 73
IS  - 5
SP  - 613
EP  - 620
DO  - 10.5937/tehnika1805613U
ER  - 

@article{
author = "Ugrinović, Vukašin and Panić, Vesna and Veljović, Đorđe and Spasojević, Pavle and Šešlija, Sanja and Janaćković, Đorđe",
year = "2018",
abstract = "Goals. The goal of this study was a development of biocompatible composite hydrogels, structurally similar to native bone tissue, by incorporation of ~60 wt % of calcium hydroxyapatite (HA) into a matrix of hydrogels. Also, a possibility to control swelling kinetic and equilibrium swelling degree (SDeq) of hydrogels, by altering the degree of neutralization of the precursor (DN) was examined. Methods. Composite hydrogels, based on HA and poly(methacrylic acid) (PMAA), were synthesized by free-radical polymerization with different DN. Theoretical content of HA in synthesized composites was 60 wt %. Composites were synthesized by methods of dynamic mechanical analysis and scanning electron microscopy. SDeq and swelling kinetic were examined in distilled water and simulated body fluid. Results. Morphological observations revealed uniform distribution and strong bond of spherical HA particles within the polymer matrix. Swelling analyses demonstrated that SDeq is directly proportional to DN, while rheological examinations indicated inverse proportion between DN and storage modulus, but due to the HA particles inclusion, mechanical properties of composites were significantly better compared to monophasic PMAA hydrogels. Significance. Simple method of synthesis of composite hydrogels with high content of filler nanoparticles is presented. Incorporation of HA nanoparticles significantly improved mechanical properties of hydrogels, while at the same time was demonstrated a possibility to control swelling kinetic by influencing the DN., Ciljevi - Cilj ove studije bio je razvoj biokompatibilnih kompozitnih hidrogelova, koji su slične strukture kao prirodno koštano tkivo, inkorporacijom ∼60 mas % kalcijum-hidroksiapatita (HA) u matricu hidro-gela. Takođe, ispitan je uticaj neutralizacije prekursora polimerne mreže na kinetiku bubrenja i ravnotežni stepen bubrenja (SDeq).Metode - Kompozitni hidrogelovi, sastavljeni od HA i poli(metakrilne kiseline) (PMAA), sintetisani su slobodno-radikalskom polimerizacijom, pri različitim stepenima neutralizacije prekursora (SN). Svi sintetisani kompoziti sadrže visok maseni udeo HA (~60 mas %). Kompoziti su okarakterisani metodama skenirajuće elektronske mikroskopije (SEM) i dinamičko-mehaničke analize (DMA). SDeq i kinetika bubrenja ispitivani su u destilovanoj vodi i simuliranoj telesnoj tečnosti (SBF). Rezultati - Morfološka ispitivanja pokazala su uniformnu raspodelu i dobru povezanost sferičnih čestica apatita sa polimernom matricom. Analiza procesa bubrenja pokazala je proporcionalnu zavisnost SN i SDeq kompozita. Reološka ispitivanja ukazala su na obrnuto proporcionalnu zavisnost između SN i vrednosti modula sačuvane energije, koji su iznosili 55130 Pa u slučaju potpune neutralizacije i 77480 Pa u slučaju 0% neutralizacije. Značaj - Predstavljena je jednostavna metoda za sintezu kompozitnih hidrogelova sa visokim masenim udelom nanočestica punioca. Inkorporacijom nanočestica HA postignuto je značajno poboljšanje mehaničkih svojstava hidrogelova, dok je istovremeno pokazano da je promenom SN moguće kontrolisati kinetiku bubrenja hidrogelova. .",
publisher = "Beograd : Savez inženjera i tehničara Srbije",
journal = "Tehnika",
title = "Synthesis and properties of nano-hydroxyapatite/poly (methacrylic acid) composite hydrogels, Uticaj neutralizacije na svojstva poroznih hidrogelova na bazi hidroksiapatita i poli(metakrilne kiseline) sintetisanih slobodno-radikalskom polimerizacijom",
volume = "73",
number = "5",
pages = "613-620",
doi = "10.5937/tehnika1805613U"
}

Ugrinović, V., Panić, V., Veljović, Đ., Spasojević, P., Šešlija, S.,& Janaćković, Đ.. (2018). Synthesis and properties of nano-hydroxyapatite/poly (methacrylic acid) composite hydrogels. in Tehnika
Beograd : Savez inženjera i tehničara Srbije., 73(5), 613-620.
https://doi.org/10.5937/tehnika1805613U

Ugrinović V, Panić V, Veljović Đ, Spasojević P, Šešlija S, Janaćković Đ. Synthesis and properties of nano-hydroxyapatite/poly (methacrylic acid) composite hydrogels. in Tehnika. 2018;73(5):613-620.
doi:10.5937/tehnika1805613U .

Ugrinović, Vukašin, Panić, Vesna, Veljović, Đorđe, Spasojević, Pavle, Šešlija, Sanja, Janaćković, Đorđe, "Synthesis and properties of nano-hydroxyapatite/poly (methacrylic acid) composite hydrogels" in Tehnika, 73, no. 5 (2018):613-620,
https://doi.org/10.5937/tehnika1805613U . .

TY  - JOUR
AU  - Juma, Habish Amal
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Potkonjak, Branislav
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2015
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3874
AB  - In this study, the sorption of cadmium ions onto sepiolite modified with hydrated iron(III) oxide, Fe(III)-sepiolite, has been investigated in natural seawater, artificial seawater, aqueous solution of NaCl of the same ionic strength as the seawater and distilled water. The sorption experiments were performed as a function of the initial solution pH value, initial metal concentration, and equilibration time, using the batch method. The equilibrium sorption data were analyzed by the Langmuir, Freundlich and Sips isotherm models and the kinetics of sorption was analyzed using the pseudo-first-order and the pseudosecond-order kinetic models. The maximum sorption capacity and the strength of the sorbate-sorbent bonds at initial pH 7 were found to decrease in the following order: distilled water > NaCl solution > artificial seawater > natural seawater. The values of parameter nS in the Sips model, which fitted the equilibrium sorption results best, showed that heterogeneity of the sorbent surface was the highest in distilled water and the lowest in natural seawater. The sorption kinetic data fitted well with the pseudo-second-order kinetic model, which suggests that the rate-limiting step in Cd2+ sorption onto Fe(III)-sepiolite could be chemisorption. The low desorption percentage in both distilled water and 0.001 M HNO3 indicated that sorption occurred mainly by chemisorption mechanisms.
AB  - U ovom radu je proučavana sorpcija jona kadmijuma iz prirodne morske vode, laboratorijski pripremljene morske vode, vodenog rastvora NaCl iste jonske jačine kao morska voda i destilovane vode, na sepiolitu modifikovanom hidratisanim gvožđe(III)-oksidom. Eksperimenti su izvedeni u šaržnim uslovima, pri različitim početnim pH vrednostima, početnim koncentracijama jona kadmijuma i vremenima uravnotežavanja. Rezultati sorpcije u ravnotežnim uslovima su analizirani primenom modela Langmira, Frojndliha i Sipsa, a kinetika sorpcije je analizirana kinetičkim modelima pseudo-prvog i pseudo-drugog reda. Utvrđeno je da maksimalni adsorpcioni kapacitet i jačina veza sorbat-sorbent pri početnoj pH 7 opadaju u nizu: destilovana voda > NaCl rastvor > laboratorijski pripremljena morska voda > prirodna morska voda. Vrednosti parametra ns u modelu Sipsa, koji najbolje opisuje eksperimentalne rezultate, pokazuju da je heterogenost površine sorbenta najveća u destilovanoj vodi i najmanja u prirodnoj morskoj vodi. Rezultati ispitivanja kinetike sorpcije se bolje fituju modelom pseudo-drugog reda, što sugeriše da stupanj koji određuje brzinu sorpcije može biti hemisorpcija. Mali stepen desorpcije i u destilovanoj vodi i u 0.001 M HNO3 je potvrdio da se joni kadmijuma vezuju za modifikovani sepiolit uglavnom hemisorpcijom.
PB  - Belgrade : Association of the Chemical Engineers of Serbia
T2  - Chemical Industry and Chemical Engineering Quarterly
T1  - The effect of salinity on the sorption of cadmium ions from aqueous medium on Fe(III)-sepiolite
T1  - Uticaj saliniteta vode na sorpciju jona kadmijuma na Fe(III)-sepiolitu
VL  - 21
IS  - 2
SP  - 295
EP  - 303
DO  - 10.2298/CICEQ140130028H
ER  - 

@article{
author = "Juma, Habish Amal and Lazarević, Slavica and Janković-Častvan, Ivona and Potkonjak, Branislav and Janaćković, Đorđe and Petrović, Rada",
year = "2015",
abstract = "In this study, the sorption of cadmium ions onto sepiolite modified with hydrated iron(III) oxide, Fe(III)-sepiolite, has been investigated in natural seawater, artificial seawater, aqueous solution of NaCl of the same ionic strength as the seawater and distilled water. The sorption experiments were performed as a function of the initial solution pH value, initial metal concentration, and equilibration time, using the batch method. The equilibrium sorption data were analyzed by the Langmuir, Freundlich and Sips isotherm models and the kinetics of sorption was analyzed using the pseudo-first-order and the pseudosecond-order kinetic models. The maximum sorption capacity and the strength of the sorbate-sorbent bonds at initial pH 7 were found to decrease in the following order: distilled water > NaCl solution > artificial seawater > natural seawater. The values of parameter nS in the Sips model, which fitted the equilibrium sorption results best, showed that heterogeneity of the sorbent surface was the highest in distilled water and the lowest in natural seawater. The sorption kinetic data fitted well with the pseudo-second-order kinetic model, which suggests that the rate-limiting step in Cd2+ sorption onto Fe(III)-sepiolite could be chemisorption. The low desorption percentage in both distilled water and 0.001 M HNO3 indicated that sorption occurred mainly by chemisorption mechanisms., U ovom radu je proučavana sorpcija jona kadmijuma iz prirodne morske vode, laboratorijski pripremljene morske vode, vodenog rastvora NaCl iste jonske jačine kao morska voda i destilovane vode, na sepiolitu modifikovanom hidratisanim gvožđe(III)-oksidom. Eksperimenti su izvedeni u šaržnim uslovima, pri različitim početnim pH vrednostima, početnim koncentracijama jona kadmijuma i vremenima uravnotežavanja. Rezultati sorpcije u ravnotežnim uslovima su analizirani primenom modela Langmira, Frojndliha i Sipsa, a kinetika sorpcije je analizirana kinetičkim modelima pseudo-prvog i pseudo-drugog reda. Utvrđeno je da maksimalni adsorpcioni kapacitet i jačina veza sorbat-sorbent pri početnoj pH 7 opadaju u nizu: destilovana voda > NaCl rastvor > laboratorijski pripremljena morska voda > prirodna morska voda. Vrednosti parametra ns u modelu Sipsa, koji najbolje opisuje eksperimentalne rezultate, pokazuju da je heterogenost površine sorbenta najveća u destilovanoj vodi i najmanja u prirodnoj morskoj vodi. Rezultati ispitivanja kinetike sorpcije se bolje fituju modelom pseudo-drugog reda, što sugeriše da stupanj koji određuje brzinu sorpcije može biti hemisorpcija. Mali stepen desorpcije i u destilovanoj vodi i u 0.001 M HNO3 je potvrdio da se joni kadmijuma vezuju za modifikovani sepiolit uglavnom hemisorpcijom.",
publisher = "Belgrade : Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry and Chemical Engineering Quarterly",
title = "The effect of salinity on the sorption of cadmium ions from aqueous medium on Fe(III)-sepiolite, Uticaj saliniteta vode na sorpciju jona kadmijuma na Fe(III)-sepiolitu",
volume = "21",
number = "2",
pages = "295-303",
doi = "10.2298/CICEQ140130028H"
}

Juma, H. A., Lazarević, S., Janković-Častvan, I., Potkonjak, B., Janaćković, Đ.,& Petrović, R.. (2015). The effect of salinity on the sorption of cadmium ions from aqueous medium on Fe(III)-sepiolite. in Chemical Industry and Chemical Engineering Quarterly
Belgrade : Association of the Chemical Engineers of Serbia., 21(2), 295-303.
https://doi.org/10.2298/CICEQ140130028H

Juma HA, Lazarević S, Janković-Častvan I, Potkonjak B, Janaćković Đ, Petrović R. The effect of salinity on the sorption of cadmium ions from aqueous medium on Fe(III)-sepiolite. in Chemical Industry and Chemical Engineering Quarterly. 2015;21(2):295-303.
doi:10.2298/CICEQ140130028H .

Juma, Habish Amal, Lazarević, Slavica, Janković-Častvan, Ivona, Potkonjak, Branislav, Janaćković, Đorđe, Petrović, Rada, "The effect of salinity on the sorption of cadmium ions from aqueous medium on Fe(III)-sepiolite" in Chemical Industry and Chemical Engineering Quarterly, 21, no. 2 (2015):295-303,
https://doi.org/10.2298/CICEQ140130028H . .

TY  - JOUR
AU  - Ahribesh, Aysha Ali
AU  - Lazarević, Slavica
AU  - Potkonjak, Branislav
AU  - Bjelajac, Andjelika
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2015
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3876
AB  - The sorption of Cd2+ from natural seawater, artificial seawater, distilled water and NaCl solution of the same ionic strength as the seawater onto zeolite modified by iron(III) oxide (Fe(III)-zeolite) was investigated. The sorption was found to be time, concentration and pH dependent. The sorption capacity at the initial pH 7 decreased in the following order: distilled water > NaCl solution > artificial seawater > natural seawater. The isotherm study showed that Langmuir isotherm model could be adequately applied for the sorption in distilled water, indicating the homogeneous monolayer coverage at Fe(III)-zeolite surface, while the Freundlich isotherm model showed a better fit than the Langmuir model of the sorption data in saline waters, indicating multilayer heterogeneous coverage at the sorbent surface. The values of Freundlich parameter n suggested that the sorption was a favorable process and bonds between Cd2+ and Fe(III)-zeolite surface were stronger in NaCl solution than in natural and artificial seawater. Kinetics analysis showed that the mechanism of Cd2+ sorption from natural seawater differed from the sorption mechanism out of distilled water, NaCl solution and artificial seawater. The intra-particle diffusion kinetic model indicated that both boundary layer diffusion and intra-particle diffusion influenced the rate of sorption.
AB  - U ovom radu je ispitivana sorpcija Cd2+ iz prirodne morske vode, laboratorijski pripremljene morske vode, destilovane vode i rastvora NaCl, iste jonske jačine kao morska voda, na zeolitu modifikovanom gvožđe(III)-oksidom. Pokazano je da sorpcija zavisi od vremena, početne koncentracije Cd2+ i pH vrednosti. Sorpcioni kapacitet Fe(III)-zeolita za Cd2+ pri početnoj pH 7 opada u sledećem nizu: destilovana voda > NaCl rastvor > laboratorijski pripremljena morska voda > prirodna morska voda. Modelovanje rezultata ispitivanja sorpcije u ravnotežnim uslovima je pokazalo da se adsorpcija iz destilovane vode može opisati Langmirovim modelom, što ukazuje na homogenu sorpciju i formiranje monosloja na površini Fe(III)-zeolita. Rezultati sorpcije iz slanih voda se bolje opisuju Frojndlihovim nego Langmirovim modelom, što ukazuje na višeslojnu sorpciju na heterogenoj površini sorbenta. Vrednosti Frojndlihovog parametra n pokazuju da je sorpcija Cd2+ na Fe(III)-zeolitu favorizovan proces i da su veze između Cd2+ i površine Fe(III)-zeolita jače u NaCl rastvoru nego u prirodnoj i laboratorijski pripremljenoj morskoj vodi. Kinetička analiza sorpcije je pokazala da se mehanizam sorpcije iz prirodne morske vode razlikuje od mehanizma sorpcije iz ostalih ispitivanih tipova vode. Kinetički model unutarčestične difuzije je pokazao da i difuzija kroz granični sloj i unutarčestična difuzija određuju brzinu sorpcije. Difuzija kroz granični sloj je u većoj meri zastupljena kod sorpcije iz morske vode nego u slučaju sorpcije iz drugih ispitivanih tipova vode.
PB  - Serbia : Association of Chemists and Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Sorption of cadmium ions from saline waters onto Fe(III)-zeolite
T1  - Sorpcija jona kadmijuma iz slanih voda na Fe(III)-zeolitu
VL  - 69
IS  - 3
SP  - 253
EP  - 260
DO  - 10.2298/HEMIND140122038A
ER  - 

@article{
author = "Ahribesh, Aysha Ali and Lazarević, Slavica and Potkonjak, Branislav and Bjelajac, Andjelika and Janaćković, Đorđe and Petrović, Rada",
year = "2015",
abstract = "The sorption of Cd2+ from natural seawater, artificial seawater, distilled water and NaCl solution of the same ionic strength as the seawater onto zeolite modified by iron(III) oxide (Fe(III)-zeolite) was investigated. The sorption was found to be time, concentration and pH dependent. The sorption capacity at the initial pH 7 decreased in the following order: distilled water > NaCl solution > artificial seawater > natural seawater. The isotherm study showed that Langmuir isotherm model could be adequately applied for the sorption in distilled water, indicating the homogeneous monolayer coverage at Fe(III)-zeolite surface, while the Freundlich isotherm model showed a better fit than the Langmuir model of the sorption data in saline waters, indicating multilayer heterogeneous coverage at the sorbent surface. The values of Freundlich parameter n suggested that the sorption was a favorable process and bonds between Cd2+ and Fe(III)-zeolite surface were stronger in NaCl solution than in natural and artificial seawater. Kinetics analysis showed that the mechanism of Cd2+ sorption from natural seawater differed from the sorption mechanism out of distilled water, NaCl solution and artificial seawater. The intra-particle diffusion kinetic model indicated that both boundary layer diffusion and intra-particle diffusion influenced the rate of sorption., U ovom radu je ispitivana sorpcija Cd2+ iz prirodne morske vode, laboratorijski pripremljene morske vode, destilovane vode i rastvora NaCl, iste jonske jačine kao morska voda, na zeolitu modifikovanom gvožđe(III)-oksidom. Pokazano je da sorpcija zavisi od vremena, početne koncentracije Cd2+ i pH vrednosti. Sorpcioni kapacitet Fe(III)-zeolita za Cd2+ pri početnoj pH 7 opada u sledećem nizu: destilovana voda > NaCl rastvor > laboratorijski pripremljena morska voda > prirodna morska voda. Modelovanje rezultata ispitivanja sorpcije u ravnotežnim uslovima je pokazalo da se adsorpcija iz destilovane vode može opisati Langmirovim modelom, što ukazuje na homogenu sorpciju i formiranje monosloja na površini Fe(III)-zeolita. Rezultati sorpcije iz slanih voda se bolje opisuju Frojndlihovim nego Langmirovim modelom, što ukazuje na višeslojnu sorpciju na heterogenoj površini sorbenta. Vrednosti Frojndlihovog parametra n pokazuju da je sorpcija Cd2+ na Fe(III)-zeolitu favorizovan proces i da su veze između Cd2+ i površine Fe(III)-zeolita jače u NaCl rastvoru nego u prirodnoj i laboratorijski pripremljenoj morskoj vodi. Kinetička analiza sorpcije je pokazala da se mehanizam sorpcije iz prirodne morske vode razlikuje od mehanizma sorpcije iz ostalih ispitivanih tipova vode. Kinetički model unutarčestične difuzije je pokazao da i difuzija kroz granični sloj i unutarčestična difuzija određuju brzinu sorpcije. Difuzija kroz granični sloj je u većoj meri zastupljena kod sorpcije iz morske vode nego u slučaju sorpcije iz drugih ispitivanih tipova vode.",
publisher = "Serbia : Association of Chemists and Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Sorption of cadmium ions from saline waters onto Fe(III)-zeolite, Sorpcija jona kadmijuma iz slanih voda na Fe(III)-zeolitu",
volume = "69",
number = "3",
pages = "253-260",
doi = "10.2298/HEMIND140122038A"
}

Ahribesh, A. A., Lazarević, S., Potkonjak, B., Bjelajac, A., Janaćković, Đ.,& Petrović, R.. (2015). Sorption of cadmium ions from saline waters onto Fe(III)-zeolite. in Hemijska industrija
Serbia : Association of Chemists and Chemical Engineers of Serbia., 69(3), 253-260.
https://doi.org/10.2298/HEMIND140122038A

Ahribesh AA, Lazarević S, Potkonjak B, Bjelajac A, Janaćković Đ, Petrović R. Sorption of cadmium ions from saline waters onto Fe(III)-zeolite. in Hemijska industrija. 2015;69(3):253-260.
doi:10.2298/HEMIND140122038A .

Ahribesh, Aysha Ali, Lazarević, Slavica, Potkonjak, Branislav, Bjelajac, Andjelika, Janaćković, Đorđe, Petrović, Rada, "Sorption of cadmium ions from saline waters onto Fe(III)-zeolite" in Hemijska industrija, 69, no. 3 (2015):253-260,
https://doi.org/10.2298/HEMIND140122038A . .

TY  - JOUR
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Onjia, Antonije E.
AU  - Krstić, Jugoslav
AU  - Janaćković, Đorđe
AU  - Petrovic, Rada
PY  - 2011
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/768
AB  - Inverse gas chromatography at infinite and finite surface coverages was applied to evaluate the surface properties of an iron-modified sepiolite sorbent, Fe-sepiolite. The adsorptions of different nonpolar and polar probes were measured in the infinite-dilution regime, in the temperature range 483-513 K. For the organic probes used, the thermodynamic parameters (free energy, enthalpy, and entropy) of adsorption and the dispersive and specific components of the free energy of adsorption were determined and are discussed in terms of specific reactions that can occur on the adsorbent surface. Following the approach of Gutmann (The Donor Acceptor Approach to Molecular Interactions; Plenum Press: New York, 1978), acid/base surface characteristics were determined. The adsorption isotherms of n-hexane, benzene, chloroform, and tetrahydrofuran were used to estimate the specific surface areas, isosteric heats of adsorption, and adsorption energy distributions for the adsorption of organic molecules.
PB  - American Chemical Society (ACS)
T2  - Industrial and Engineering Chemistry Research
T1  - Surface Characterization of Iron-Modified Sepiolite by Inverse Gas Chromatography
VL  - 50
IS  - 20
SP  - 11467
EP  - 11475
DO  - 10.1021/ie200595n
ER  - 

@article{
author = "Lazarević, Slavica and Janković-Častvan, Ivona and Onjia, Antonije E. and Krstić, Jugoslav and Janaćković, Đorđe and Petrovic, Rada",
year = "2011",
abstract = "Inverse gas chromatography at infinite and finite surface coverages was applied to evaluate the surface properties of an iron-modified sepiolite sorbent, Fe-sepiolite. The adsorptions of different nonpolar and polar probes were measured in the infinite-dilution regime, in the temperature range 483-513 K. For the organic probes used, the thermodynamic parameters (free energy, enthalpy, and entropy) of adsorption and the dispersive and specific components of the free energy of adsorption were determined and are discussed in terms of specific reactions that can occur on the adsorbent surface. Following the approach of Gutmann (The Donor Acceptor Approach to Molecular Interactions; Plenum Press: New York, 1978), acid/base surface characteristics were determined. The adsorption isotherms of n-hexane, benzene, chloroform, and tetrahydrofuran were used to estimate the specific surface areas, isosteric heats of adsorption, and adsorption energy distributions for the adsorption of organic molecules.",
publisher = "American Chemical Society (ACS)",
journal = "Industrial and Engineering Chemistry Research",
title = "Surface Characterization of Iron-Modified Sepiolite by Inverse Gas Chromatography",
volume = "50",
number = "20",
pages = "11467-11475",
doi = "10.1021/ie200595n"
}

Lazarević, S., Janković-Častvan, I., Onjia, A. E., Krstić, J., Janaćković, Đ.,& Petrovic, R.. (2011). Surface Characterization of Iron-Modified Sepiolite by Inverse Gas Chromatography. in Industrial and Engineering Chemistry Research
American Chemical Society (ACS)., 50(20), 11467-11475.
https://doi.org/10.1021/ie200595n

Lazarević S, Janković-Častvan I, Onjia AE, Krstić J, Janaćković Đ, Petrovic R. Surface Characterization of Iron-Modified Sepiolite by Inverse Gas Chromatography. in Industrial and Engineering Chemistry Research. 2011;50(20):11467-11475.
doi:10.1021/ie200595n .

Lazarević, Slavica, Janković-Častvan, Ivona, Onjia, Antonije E., Krstić, Jugoslav, Janaćković, Đorđe, Petrovic, Rada, "Surface Characterization of Iron-Modified Sepiolite by Inverse Gas Chromatography" in Industrial and Engineering Chemistry Research, 50, no. 20 (2011):11467-11475,
https://doi.org/10.1021/ie200595n . .

TY  - JOUR
AU  - Marjanović, Vesna
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Potkonjak, Branislav
AU  - Janaćković, Đorđe
AU  - Petrović, Radomir
PY  - 2011
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4085
AB  - Natural and acid-activated sepiolite samples were functionalized with (3-Mercaptopropyl)trimethoxysilane.
By X-ray powder diffraction, Fourier transform infrared spectroscopy, and differential thermal
analysis it was shown that functionalization of sepiolites by grafting silane reagents occurs mainly on
the surface, whereby their crystalline structure remained unchanged. The efficiency of the adsorbents
in Cr(VI) removal from aqueous solutions follows the order: functionalized acid-activated sepiolite
> functionalized natural sepiolite > acid-activated sepiolite > natural sepiolite. As the number of silanol
groups on the sepiolite surface increased during the acid activation, the silane functionalization increased
and this led to an increase in Cr(VI) adsorption. The adsorption capacity strongly depended on the pH
of the solution from which the adsorption occurred. Maximum Cr(VI) removal was ca. 8.0mg Cr(VI) per
g of functionalized acid-activated sepiolite at initial pH 3, when the pH of solution reached 4.7, and
ca. 2.7mg Cr(VI) per g of functionalized natural sepiolite at initial pH 2, when the pH of the solution
reached 2.5. Cr(VI) removal by the functionalized sepiolites was mainly attributed to electrostatic attraction
between the protonated mercapto groups and the negatively charged Cr(VI) species. The sorption
isotherms showed that Cr(VI) removal by both functionalized sepiolites for all initial investigated solution
pH values is well described using the Dubinin–Radushkevich model. The thermodynamic data suggest
spontaneity of the major physical adsorption process at 298 K.
PB  - Elsevier
T2  - Chemical Engineering Journal
T1  - Chromium (VI) removal from aqueous solutions using mercaptosilane functionalized sepiolites
VL  - 166
IS  - 1
SP  - 198
EP  - 206
DO  - 10.1016/j.cej.2010.10.062
ER  - 

@article{
author = "Marjanović, Vesna and Lazarević, Slavica and Janković-Častvan, Ivona and Potkonjak, Branislav and Janaćković, Đorđe and Petrović, Radomir",
year = "2011",
abstract = "Natural and acid-activated sepiolite samples were functionalized with (3-Mercaptopropyl)trimethoxysilane.
By X-ray powder diffraction, Fourier transform infrared spectroscopy, and differential thermal
analysis it was shown that functionalization of sepiolites by grafting silane reagents occurs mainly on
the surface, whereby their crystalline structure remained unchanged. The efficiency of the adsorbents
in Cr(VI) removal from aqueous solutions follows the order: functionalized acid-activated sepiolite
> functionalized natural sepiolite > acid-activated sepiolite > natural sepiolite. As the number of silanol
groups on the sepiolite surface increased during the acid activation, the silane functionalization increased
and this led to an increase in Cr(VI) adsorption. The adsorption capacity strongly depended on the pH
of the solution from which the adsorption occurred. Maximum Cr(VI) removal was ca. 8.0mg Cr(VI) per
g of functionalized acid-activated sepiolite at initial pH 3, when the pH of solution reached 4.7, and
ca. 2.7mg Cr(VI) per g of functionalized natural sepiolite at initial pH 2, when the pH of the solution
reached 2.5. Cr(VI) removal by the functionalized sepiolites was mainly attributed to electrostatic attraction
between the protonated mercapto groups and the negatively charged Cr(VI) species. The sorption
isotherms showed that Cr(VI) removal by both functionalized sepiolites for all initial investigated solution
pH values is well described using the Dubinin–Radushkevich model. The thermodynamic data suggest
spontaneity of the major physical adsorption process at 298 K.",
publisher = "Elsevier",
journal = "Chemical Engineering Journal",
title = "Chromium (VI) removal from aqueous solutions using mercaptosilane functionalized sepiolites",
volume = "166",
number = "1",
pages = "198-206",
doi = "10.1016/j.cej.2010.10.062"
}

Marjanović, V., Lazarević, S., Janković-Častvan, I., Potkonjak, B., Janaćković, Đ.,& Petrović, R.. (2011). Chromium (VI) removal from aqueous solutions using mercaptosilane functionalized sepiolites. in Chemical Engineering Journal
Elsevier., 166(1), 198-206.
https://doi.org/10.1016/j.cej.2010.10.062

Marjanović V, Lazarević S, Janković-Častvan I, Potkonjak B, Janaćković Đ, Petrović R. Chromium (VI) removal from aqueous solutions using mercaptosilane functionalized sepiolites. in Chemical Engineering Journal. 2011;166(1):198-206.
doi:10.1016/j.cej.2010.10.062 .

Marjanović, Vesna, Lazarević, Slavica, Janković-Častvan, Ivona, Potkonjak, Branislav, Janaćković, Đorđe, Petrović, Radomir, "Chromium (VI) removal from aqueous solutions using mercaptosilane functionalized sepiolites" in Chemical Engineering Journal, 166, no. 1 (2011):198-206,
https://doi.org/10.1016/j.cej.2010.10.062 . .

TY  - JOUR
AU  - Jokić, Bojan
AU  - Drmanić, Saša Ž.
AU  - Radetić, Tamara
AU  - Krstić, Jugoslav
AU  - Petrovic, R.
AU  - Orlovic, A.
AU  - Janaćković, Đorđe
PY  - 2010
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/715
AB  - Submicron carbon spherical particles were obtained by polycondensation of resorcinol and formaldehyde in a solution and subsequent ultrasonic spray pyrolysis of the prepared sol. Microscopic characterization indicates the regular spherical shape of the obtained particles and sphere diameters in 200-700 nm range. The carbon spheres are amorphous as confirmed by electron diffraction, EELS, XRD and HREM characterization. Activation procedure was performed with H2O in a nitrogen flow for 15 and 30 min at 800 degrees C. The activation procedure preserved the initial spherical shapes of the particles while the particle porosity and specific surface area were increased. The amount of surface oxygen functionalities was also increased by activation procedure as indicated by FTIR analysis.
PB  - Elsevier
T2  - Materials Letters
T1  - Synthesis of submicron carbon spheres by the ultrasonic spray pyrolysis method
VL  - 64
IS  - 20
SP  - 2173
EP  - 2176
DO  - 10.1016/j.matlet.2010.06.066
ER  - 

@article{
author = "Jokić, Bojan and Drmanić, Saša Ž. and Radetić, Tamara and Krstić, Jugoslav and Petrovic, R. and Orlovic, A. and Janaćković, Đorđe",
year = "2010",
abstract = "Submicron carbon spherical particles were obtained by polycondensation of resorcinol and formaldehyde in a solution and subsequent ultrasonic spray pyrolysis of the prepared sol. Microscopic characterization indicates the regular spherical shape of the obtained particles and sphere diameters in 200-700 nm range. The carbon spheres are amorphous as confirmed by electron diffraction, EELS, XRD and HREM characterization. Activation procedure was performed with H2O in a nitrogen flow for 15 and 30 min at 800 degrees C. The activation procedure preserved the initial spherical shapes of the particles while the particle porosity and specific surface area were increased. The amount of surface oxygen functionalities was also increased by activation procedure as indicated by FTIR analysis.",
publisher = "Elsevier",
journal = "Materials Letters",
title = "Synthesis of submicron carbon spheres by the ultrasonic spray pyrolysis method",
volume = "64",
number = "20",
pages = "2173-2176",
doi = "10.1016/j.matlet.2010.06.066"
}

Jokić, B., Drmanić, S. Ž., Radetić, T., Krstić, J., Petrovic, R., Orlovic, A.,& Janaćković, Đ.. (2010). Synthesis of submicron carbon spheres by the ultrasonic spray pyrolysis method. in Materials Letters
Elsevier., 64(20), 2173-2176.
https://doi.org/10.1016/j.matlet.2010.06.066

Jokić B, Drmanić SŽ, Radetić T, Krstić J, Petrovic R, Orlovic A, Janaćković Đ. Synthesis of submicron carbon spheres by the ultrasonic spray pyrolysis method. in Materials Letters. 2010;64(20):2173-2176.
doi:10.1016/j.matlet.2010.06.066 .

Jokić, Bojan, Drmanić, Saša Ž., Radetić, Tamara, Krstić, Jugoslav, Petrovic, R., Orlovic, A., Janaćković, Đorđe, "Synthesis of submicron carbon spheres by the ultrasonic spray pyrolysis method" in Materials Letters, 64, no. 20 (2010):2173-2176,
https://doi.org/10.1016/j.matlet.2010.06.066 . .

TY  - JOUR
AU  - Tanaskovic, N.
AU  - Radovanović, Z.
AU  - Dokic, V.
AU  - Krstić, Jugoslav
AU  - Drmanić, Saša Ž.
AU  - Janaćković, Đorđe
AU  - Petrovic, R.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/527
AB  - Mesoporous titania with well-crystallized anatase phase was synthesized by nonhydrolytic sol-gel process combined with solvothermal treatment. Titanium-isopropoxide, titanium-tetrachloride, and carbon-tetrachloride were used for synthesis under nitrogen atmosphere in a glove box. The obtained mixture was heated in an autoclave at 140 degrees C for 3 h and 30 h. XRD analysis showed that dry gels contained anatase phase with low crystallinity, while powders obtained by calcination of dry gels at 500 degrees C for 3 h consisted of pure anatase with high crystallinity. SEM analysis of dried gels and powders shows agglomerates of spherical particles of the size similar to 300 nm. The TEM micrographs confirmed the nanoscale size of the titania powders, with the primary particle size of about 20 nm. Titania powders exhibit maximum pore diameter of 13.2 nm and 9.5 nm for gelation time 3 h and 30 h, respectively. The photocatalytic activity of such synthesized titania is superior to that of commercial photocatalyst Degussa P-25.
PB  - Academic Press Ltd- Elsevier Science Ltd, London
T2  - Superlattices and Microstructures
T1  - Synthesis of mesoporous nanocrystalline titania powders by nonhydrolitic sol-gel method
VL  - 46
IS  - 1-2
SP  - 217
EP  - 222
DO  - 10.1016/j.spmi.2008.12.028
ER  - 

@article{
author = "Tanaskovic, N. and Radovanović, Z. and Dokic, V. and Krstić, Jugoslav and Drmanić, Saša Ž. and Janaćković, Đorđe and Petrovic, R.",
year = "2009",
abstract = "Mesoporous titania with well-crystallized anatase phase was synthesized by nonhydrolytic sol-gel process combined with solvothermal treatment. Titanium-isopropoxide, titanium-tetrachloride, and carbon-tetrachloride were used for synthesis under nitrogen atmosphere in a glove box. The obtained mixture was heated in an autoclave at 140 degrees C for 3 h and 30 h. XRD analysis showed that dry gels contained anatase phase with low crystallinity, while powders obtained by calcination of dry gels at 500 degrees C for 3 h consisted of pure anatase with high crystallinity. SEM analysis of dried gels and powders shows agglomerates of spherical particles of the size similar to 300 nm. The TEM micrographs confirmed the nanoscale size of the titania powders, with the primary particle size of about 20 nm. Titania powders exhibit maximum pore diameter of 13.2 nm and 9.5 nm for gelation time 3 h and 30 h, respectively. The photocatalytic activity of such synthesized titania is superior to that of commercial photocatalyst Degussa P-25.",
publisher = "Academic Press Ltd- Elsevier Science Ltd, London",
journal = "Superlattices and Microstructures",
title = "Synthesis of mesoporous nanocrystalline titania powders by nonhydrolitic sol-gel method",
volume = "46",
number = "1-2",
pages = "217-222",
doi = "10.1016/j.spmi.2008.12.028"
}

Tanaskovic, N., Radovanović, Z., Dokic, V., Krstić, J., Drmanić, S. Ž., Janaćković, Đ.,& Petrovic, R.. (2009). Synthesis of mesoporous nanocrystalline titania powders by nonhydrolitic sol-gel method. in Superlattices and Microstructures
Academic Press Ltd- Elsevier Science Ltd, London., 46(1-2), 217-222.
https://doi.org/10.1016/j.spmi.2008.12.028

Tanaskovic N, Radovanović Z, Dokic V, Krstić J, Drmanić SŽ, Janaćković Đ, Petrovic R. Synthesis of mesoporous nanocrystalline titania powders by nonhydrolitic sol-gel method. in Superlattices and Microstructures. 2009;46(1-2):217-222.
doi:10.1016/j.spmi.2008.12.028 .

Tanaskovic, N., Radovanović, Z., Dokic, V., Krstić, Jugoslav, Drmanić, Saša Ž., Janaćković, Đorđe, Petrovic, R., "Synthesis of mesoporous nanocrystalline titania powders by nonhydrolitic sol-gel method" in Superlattices and Microstructures, 46, no. 1-2 (2009):217-222,
https://doi.org/10.1016/j.spmi.2008.12.028 . .

TY  - JOUR
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Jovanović, Dušan
AU  - Milonjić, Slobodan
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2007
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4122
AB  - The adsorption mechanisms of Pb2+, Cd2+ and Sr2+ ions on natural sepiolite and the influence of acid treatment on the adsorption capacity of sepiolite were investigated. The point of zero charge, pHpzc, is 7.4 ± 0.1 for natural sepiolite and 6.9 ± 0.1 for partially acid-activated sepiolite. The shift of the pHpzc of sepiolites toward lower pH values in solutions of Pb2+ and Cd2+ ions indicates that specific adsorption of these cations on natural and acid-activated sepiolites occurred, which was more pronounced for Pb2+ ions than for Cd2+ ions. There was no shift of the pHpzc in solution containing Sr2+ ions, suggesting that specific adsorption of this cation did not occur. The affinity for ion exchange with the Mg2+ ions from the sepiolite structure was the highest for Pb2+ ions, then Cd2+, whereas the affinity for Sr2+ ions was negligible. The adsorption isotherms suggest that the sequence of the efficiency of the sepiolites adsorption is Pb2+ > Cd2+ > Sr2+. The retention of Pb2+ and Cd2+ ions by sepiolite occurs dominantly by specific adsorption and exchange of Mg2+ ions from the sepiolite structure. The concentration in the external outer sphere of the Stern layer by electrostatic forces is the dominant mechanism for the retention of Sr2+ ions on the surface of sepiolites. Despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed, as a result of the decreasing number of Mg-OH groups, as main centers for specific adsorption, and the number of Mg2+ ions available for ion exchange with Pb2+, Cd2+ and Sr2+ ions. The removal of Mg-OH groups from the sepiolite also resulted in a decrease in the point of zero charge and an increase of the relative surface acidity, from 2.6 ± 0.1 for the natural to 6.4 ± 0.1 for the acid-activated sepiolite.
PB  - Elsevier
T2  - Applied Clay Science
T1  - Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites
VL  - 37
IS  - 1-2
SP  - 47
EP  - 57
DO  - 10.1016/j.clay.2006.11.008
ER  - 

@article{
author = "Lazarević, Slavica and Janković-Častvan, Ivona and Jovanović, Dušan and Milonjić, Slobodan and Janaćković, Đorđe and Petrović, Rada",
year = "2007",
abstract = "The adsorption mechanisms of Pb2+, Cd2+ and Sr2+ ions on natural sepiolite and the influence of acid treatment on the adsorption capacity of sepiolite were investigated. The point of zero charge, pHpzc, is 7.4 ± 0.1 for natural sepiolite and 6.9 ± 0.1 for partially acid-activated sepiolite. The shift of the pHpzc of sepiolites toward lower pH values in solutions of Pb2+ and Cd2+ ions indicates that specific adsorption of these cations on natural and acid-activated sepiolites occurred, which was more pronounced for Pb2+ ions than for Cd2+ ions. There was no shift of the pHpzc in solution containing Sr2+ ions, suggesting that specific adsorption of this cation did not occur. The affinity for ion exchange with the Mg2+ ions from the sepiolite structure was the highest for Pb2+ ions, then Cd2+, whereas the affinity for Sr2+ ions was negligible. The adsorption isotherms suggest that the sequence of the efficiency of the sepiolites adsorption is Pb2+ > Cd2+ > Sr2+. The retention of Pb2+ and Cd2+ ions by sepiolite occurs dominantly by specific adsorption and exchange of Mg2+ ions from the sepiolite structure. The concentration in the external outer sphere of the Stern layer by electrostatic forces is the dominant mechanism for the retention of Sr2+ ions on the surface of sepiolites. Despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed, as a result of the decreasing number of Mg-OH groups, as main centers for specific adsorption, and the number of Mg2+ ions available for ion exchange with Pb2+, Cd2+ and Sr2+ ions. The removal of Mg-OH groups from the sepiolite also resulted in a decrease in the point of zero charge and an increase of the relative surface acidity, from 2.6 ± 0.1 for the natural to 6.4 ± 0.1 for the acid-activated sepiolite.",
publisher = "Elsevier",
journal = "Applied Clay Science",
title = "Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites",
volume = "37",
number = "1-2",
pages = "47-57",
doi = "10.1016/j.clay.2006.11.008"
}

Lazarević, S., Janković-Častvan, I., Jovanović, D., Milonjić, S., Janaćković, Đ.,& Petrović, R.. (2007). Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites. in Applied Clay Science
Elsevier., 37(1-2), 47-57.
https://doi.org/10.1016/j.clay.2006.11.008

Lazarević S, Janković-Častvan I, Jovanović D, Milonjić S, Janaćković Đ, Petrović R. Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites. in Applied Clay Science. 2007;37(1-2):47-57.
doi:10.1016/j.clay.2006.11.008 .

Lazarević, Slavica, Janković-Častvan, Ivona, Jovanović, Dušan, Milonjić, Slobodan, Janaćković, Đorđe, Petrović, Rada, "Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites" in Applied Clay Science, 37, no. 1-2 (2007):47-57,
https://doi.org/10.1016/j.clay.2006.11.008 . .