Synthesis and characterization of composites of polyaniline and metal/organic frameworks based on Zn(II)-oxydicarboxylates

U ovoj tezi po prvi put su sintetisani kompoziti MOF-5, tipičnog predstavnika metalo-organskih mrežnih struktura (MOF), i polianilina (PANI), jednog od najvažnijih elektroprovodnih polimera. MOF-5 je mikroporozni, kristalni, elektroneprovodan materijal, velike specifične površine i poroznosti, koji se sastoji od Zn4O jedinica povezanih 1,4-benzendikarboksilatnim linkerima. PANI je konjugovani polimer koji egzistira u različitim kiselinsko-baznim i redoks oblicima i pokazuje visoku električnu provodljivost, ali ima malu specifičnu površinu. U prvom delu teze razvijena je efikasna sinteza čiste faze MOF-5, bazirana na korišćenju anhidrovanog cink acetata kao prekursora. Dodavanjem vode za in situ formiranje različitih cink acetata hidrata i karakterizacijom produkata nađeno je da optimalna količina vode za sintezu čistog kubičnog MOF-5 iznosi 0,250,5 molova vode po molu Zn2+. MOF-5 sintetisan pri molskom odnosu H2O/Zn2+ = 0,5 pokazivao je najveću specifičnu površinu SBET (1937 m2g1) i korišćen je za sinteze kompozita. PANI je sintetisan oksidativnom polimerizacijom anilina u prisustvu HCl i bez dodate kiseline. Kompoziti su okarakterisani brojnim fizičkohemijskim tehnikama. Sintetičkim postupkom, u kome je neprovodni oblik PANI rastvoren u DMF mešan sa MOF-5 u različitim masenim odnosima, dobijeni su mikroporozni kompoziti veoma velike SBET (najveća 2700 m2g1) i niske električne provodljivosti. Postupkom mehaničko-hemijske sinteze, u kome su elektroprovodni oblik PANI i MOF-5 mehanički sitnjeni u različitim masenim odnosima u prisustvu male količine hloroforma, dobijeni su mikroporozni kompoziti koji su pokazivali i elektroprovodljivost (najveća 1,0103 Scm1) i velike SBET (najveća 850 m2g-1). Kompoziti MOF-5/PANI predstavljaju obećavajuće kandidate za niz primena.In this thesis, for the first time, composites of MOF-5, a typical representative of metal-organic network structures (MOF), and polyaniline (PANI), one of the most important electrically conductive polymers, were synthesized. MOF-5 is a microporous, crystalline, non-conductive material, with a large specific surface area and porosity, consisting of Zn4O units connected by 1,4-benzenedicarboxylate linkers. PANI is a conjugated polymer that exist in various acid-base and redox forms and exhibits high electrical conductivity, but has small specific surface. In the first part of the thesis, efficient synthesis of pure phase MOF-5 was developed, based on the use of anhydrous zinc acetate as a precursor. By adding water for in situ formation of various zinc acetate hydrates and by characterization of the products it was found that the optimal amount of water for the synthesis of pure cubic MOF-5 is 0.250.5 moles of water per mole of Zn2+. MOF-5 synthesized at the H2O / Zn2+ = 0.5 molar ratio showed the highest specific surface area SBET of 1937 m2g-1 and was used for composite syntheses. PANI was synthesized by the oxidative polymerization of aniline in the presence of HCl and without added acid. Composites are characterized by a number of physicochemical techniques. Synthetic process in which the non-conductive form of PANI dissolved in DMF was mixed with MOF-5 in different mass ratios led to microporous composites of very high SBET (maximum 2700 m2g1) and low electrical conductivity. The process of mechano-chemical synthesis, in which the conductive form PANI and MOF-5 were mechanically crushed in different mass ratios in the presence of a small amount of chloroform, led to microporous composites that showed both electrical conductivity (maximum 1.0 103 Scm1) and large values of SBET (maximum 850 m2g-1). MOF-5/PANI composites are promising candidates for a range of applications

Optical spectroscopy of plasma induced by irradiation of animal bone with TEA CO2 laser

The application of laser-induced breakdown spectroscopy (LIBS) for the elemental analysis of pig shoulder bone samples is reported. Measurements were performed using a compact laboratory-made TEA CO2 laser with low pulse energy. The recorded spectra consisted of well-defined lines of atoms and single charged ions of Ca, Mg, P, and other constituent elements, with a good signal-to-noise ratio suitable for spectrochemical analysis. Based on the ICP quantitative analysis of the bone sample, the limits of detection of LIBS analysis were estimated for Mg (16 ppm) and Na (940 ppm). Plasma parameters, temperature, and electron number density were determined by measuring Stark widths and relative intensities of the C and Mg ionic and atomic spectral lines.The book of abstracts available at: [http://www.socphyschemserb.org/media/physical-chemistry-2021/abstracts.pdf

Permanent disposal of Cs ions in the form of dense pollucite ceramics having low thermal expansion coefficient

A promising method for removal of Cs ions from water and their incorporation into stable crystal structure ready for safe and permanent disposal was described. Cs-exchanged X zeolite was hot-pressed at temperature ranging from 800 to 950 °C to fabricate dense pollucite ceramics. It was found that the application of external pressure reduced the pollucite formation temperature. The effect of sintering temperature on density, phase composition and mechanical properties was investigated. The highest density of 92.5 %TD and the highest compressive strength of 79 MPa were measured in pollucite hot-pressed at 950 °C for 3 h. Heterogeneity of samples obtained at 950 °C was determined using scanning electron microscopy. The pollucite hot-pressed at 950 °C had low linear thermal expansion coefficient of ∼4.67 × 10−6 K−1 in the temperature range from 100 to 1000 °C. © 201

Radionuclides and heavy metals in soil around the coal-fired power plant "Kostolac"

Ovaj rad je fokusiran na određivanje koncentracije aktivnosti radionuklida (210Pb, 238U, 235U, 226Ra, 232Th i 40K) i koncentracije teških metala (Pb, Mn i Zn ) u površinskom sloju zemljišta okoline termoelektrane "Kostolac A". Tehnike koje su korišćene za analizu pomenutih radionuklida i teških metala su gamaspektometrija i atomska apsorpciona spektrometrija, redom. Srednje vrednosti koncentracija aktivnosti ispitanih radionuklida, izražene u Bq/kg, iznosile su: 76,7 za 210Pb; 67,2 za 238U; 4,1 za 235U; 29 za 226Ra; 50,1 za 232Th i 611 za 40K. Srednje vrednosti koncentracija teških metala, izražene u mg/kg, iznosile su: 28 za Pb; 775,4 za Mn i 105,5 za Zn. Rezultati ove studije su ukazali da rad termoelektrane nema značajan negativan uticaj na okolinu u pogledu sadržaja radionuklida i teških metala.This study is focused on determination of the activity concentration of radionuclides (210Pb, 238U, 235U, 226Ra, 232Th i 40K) and concentration of heavy metals (Pb, Mn i Zn) in surface layer of soil around coal-fired power plant "Kostolac A". The techniques used to analyze of mentioned radionuclides and heavy metals are gamma spectometry and atomic absorption spectrometry, respectively. The mean values of activity concentrations of investigated radionuclides, expressed as Bq/kg, were: 76.7 for 210Pb, 67.2 for 238U, 4.1 for 235U, 29 for 226Ra, 50.1 for 232Th and 611 for 40K. The mean concentrations of heavy metals, expressed as mg/kg, were 28 for Pb, 775.4 for Mn and 105.5 for Zn. The obtained results indicated that operation of the coal fired power plant has no significant negative impact on the surrounding environment with regard to the content of investigated radionuclides and heavy metals12. Savetovanje Održivi razvoj Braničevskog okruga i energetskog kompleksa Kostolac : Maj 31., Kostolac, 2018

Ultrasound and shacking-assisted water-leaching of anions and cations from fly ash

Two mechanical extraction techniques were used for the extraction of environmentaly interesting components of coal fly ash: shaking, during which the extraction process lasted from 6 up to 24 h, and sonication that lasted from 15 up to 60 min, using water as extractant. The concentration of anions in fly ash extracts was determined by ion chromatography, while atomic absorption spectrometry was used for determination of: As, Pb, Cd, Ni, Cr, Zn, Cu, Fe, Mn and Al. The ultrasonication yielded slightly higher amounts of extracted anions as well as Pb, Al, Mn and Fe cations, while shaking-assisted extraction was more efficient for the Cr, As, Zn and Ni ions. The changes in pH value, particle size distribution within colloid solution, zeta potential and conductivity during ultrasound-assisted extraction were measured in order to explain changes that occur on the surface of fly ash particles contacting water and different processes (adsorption, ion exchange and flocculation) that develop under natural conditions. Principal Component Analysis was used for assessing the effect of observed process parameters. It is essential to evaluate quantity of these elements leachable from coal fly ash into the surface waters in natural conditions in order to prevent contamination of the environment

Safe trapping of Cs radionuclides in sintered matrix of zeolites

Cesium aluminosilicate phases are of the great interest as possible host for Cs immobilization in radioactive waste management. The possibility to use zeolite as a host material for radioactive Cs immobilization was investigated. Cs-exchanged forms of clinoptilolite and 13X which were prepared by ion-exchange treatment were compacted. The powders compacts of exchanged zeolites were thermally treated at 1200 °C. The XRD analysis showed that Cs was successfully immobilized after heat treatment by formation of stable cesium-aluminosilicate ceramic forms. Thermal and mechanical properties of the sintered samples were investigated. From the perspective of these characteristics, Cs-exchanged zeolite (clinoptilolite and 13 X) can be considered as a potential material for safe waste disposal

Degradation of Organic Pollutants by Gamma Irradiation: Future Perspective

Worldwide water bodies have been affected by toxic effluents of industries, such as organic compounds, and are continuously deteriorating the environment as industrialization coupled with urbanization has caused the excess release of wastewater. Finding a proper wastewater treatment is of the greatest importance. Gamma irradiation technique, as one of the advanced oxidation techniques, has been widely investigated as a technique for degradation of organic molecules. It has been shown that this method has the potential to be effectively applied for degradation of toxic colorants which show high persistence to degradation. Although the literature abounds with degradation studies of different organic molecules using a wide range of irradiation dozes and doze rates, according to available data, no such irradiation facility exists, mostly due to high doses and expensive equipment needed to be installed. A mechanism of degradation was proposed: generated reactive species non-specifically react with organic compounds leading to their partial or complete degradation. In recent advances, gamma irradiation was coupled with other wastewater treatment technologies to reduce needed doses. Coupling of gamma irradiation was achieved with addition of oxidants which resulted in increased number of reactive species, then coupling with solid matrices, biological treatment, which all lead to additional destabilization of organic molecules. This way, combining different methods of wastewater purification opens new possibilities and may enable the design of a new modular, or even mobile, plant that will satisfy all the needs for its wide commercial application. As a result, a sustainable development goal can be more easily reachable, i.e., sustainable water resources management in future industrial zones and smart cities may be possible without generation of waste transfer into another media.15th International symposium „Novel technologies and sustainable development", October 20-21 2023, Leskovac

Safe trapping of Cs radionuclides in sintered matrix of zeolites

Cesium aluminosilicate phases are of the great interest as possible host for Cs immobilization in radioactive waste management. The possibility to use zeolite as a host material for radioactive Cs immobilization was investigated. Cs-exchanged forms of clinoptilolite and 13X which were prepared by ion-exchange treatment were compacted. The powders compacts of exchanged zeolites were thermally treated at 1200 °C. The XRD analysis showed that Cs was successfully immobilized after heat treatment by formation of stable cesium-aluminosilicate ceramic forms. Thermal and mechanical properties of the sintered samples were investigated. From the perspective of these characteristics, Cs-exchanged zeolite (clinoptilolite and 13 X) can be considered as a potential material for safe waste disposal

Synthesis and characterization of composites of polyaniline and metal/organic frameworks based on Zn(II)-oxydicarboxylates

U ovoj tezi po prvi put su sintetisani kompoziti MOF-5, tipičnog predstavnika metalo-organskih mrežnih struktura (MOF), i polianilina (PANI), jednog od najvažnijih elektroprovodnih polimera. MOF-5 je mikroporozni, kristalni, elektroneprovodan materijal, velike specifične površine i poroznosti, koji se sastoji od Zn4O jedinica povezanih 1,4-benzendikarboksilatnim linkerima. PANI je konjugovani polimer koji egzistira u različitim kiselinsko-baznim i redoks oblicima i pokazuje visoku električnu provodljivost, ali ima malu specifičnu površinu. U prvom delu teze razvijena je efikasna sinteza čiste faze MOF-5, bazirana na korišćenju anhidrovanog cink acetata kao prekursora. Dodavanjem vode za in situ formiranje različitih cink acetata hidrata i karakterizacijom produkata nađeno je da optimalna količina vode za sintezu čistog kubičnog MOF-5 iznosi 0,250,5 molova vode po molu Zn2+. MOF-5 sintetisan pri molskom odnosu H2O/Zn2+ = 0,5 pokazivao je najveću specifičnu površinu SBET (1937 m2g1) i korišćen je za sinteze kompozita. PANI je sintetisan oksidativnom polimerizacijom anilina u prisustvu HCl i bez dodate kiseline. Kompoziti su okarakterisani brojnim fizičkohemijskim tehnikama. Sintetičkim postupkom, u kome je neprovodni oblik PANI rastvoren u DMF mešan sa MOF-5 u različitim masenim odnosima, dobijeni su mikroporozni kompoziti veoma velike SBET (najveća 2700 m2g1) i niske električne provodljivosti. Postupkom mehaničko-hemijske sinteze, u kome su elektroprovodni oblik PANI i MOF-5 mehanički sitnjeni u različitim masenim odnosima u prisustvu male količine hloroforma, dobijeni su mikroporozni kompoziti koji su pokazivali i elektroprovodljivost (najveća 1,0103 Scm1) i velike SBET (najveća 850 m2g-1). Kompoziti MOF-5/PANI predstavljaju obećavajuće kandidate za niz primena.In this thesis, for the first time, composites of MOF-5, a typical representative of metal-organic network structures (MOF), and polyaniline (PANI), one of the most important electrically conductive polymers, were synthesized. MOF-5 is a microporous, crystalline, non-conductive material, with a large specific surface area and porosity, consisting of Zn4O units connected by 1,4-benzenedicarboxylate linkers. PANI is a conjugated polymer that exist in various acid-base and redox forms and exhibits high electrical conductivity, but has small specific surface. In the first part of the thesis, efficient synthesis of pure phase MOF-5 was developed, based on the use of anhydrous zinc acetate as a precursor. By adding water for in situ formation of various zinc acetate hydrates and by characterization of the products it was found that the optimal amount of water for the synthesis of pure cubic MOF-5 is 0.250.5 moles of water per mole of Zn2+. MOF-5 synthesized at the H2O / Zn2+ = 0.5 molar ratio showed the highest specific surface area SBET of 1937 m2g-1 and was used for composite syntheses. PANI was synthesized by the oxidative polymerization of aniline in the presence of HCl and without added acid. Composites are characterized by a number of physicochemical techniques. Synthetic process in which the non-conductive form of PANI dissolved in DMF was mixed with MOF-5 in different mass ratios led to microporous composites of very high SBET (maximum 2700 m2g1) and low electrical conductivity. The process of mechano-chemical synthesis, in which the conductive form PANI and MOF-5 were mechanically crushed in different mass ratios in the presence of a small amount of chloroform, led to microporous composites that showed both electrical conductivity (maximum 1.0 103 Scm1) and large values of SBET (maximum 850 m2g-1). MOF-5/PANI composites are promising candidates for a range of applications

Ultrasound and shacking-assisted water-leaching of anions and cations from fly ash

Two mechanical extraction techniques were used for the extraction of environmentaly interesting elements from coal fly ash: shaking, in which the extraction process lasted from 6 to 24 hours, and ultrasonic sonication during 15 to 60 minutes, with water as extractant. The concentration of anions in fly ash extracts were determined by ion chromatography, while atomic absorption spectrometry was used for determination of: As, Pb, Cd, Ni, Cr, Zn, Cu, Fe, Mn and Al. The ultrasonic sonication yielded slightly higher amounts of extracted anions and Pb, Al, Mn and Fe, while shaking-assisted extraction was more efficient for the Cr, As, Zn and Ni ions. The changes in pH value, particle size distribution in colloid, zeta potential and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of fly ash particles in contact with water and different processes (adsorption, ion exchange, flocculation) that occur in environmental conditions. Principal Component Analysis were used for assessing the effect of observed process parameters. Essential from a practical point of view is a quantitative evaluation of these elements leachable from coal fly ash to surface waters in environmental conditions and contamination of the environment. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. III45012 i br. III43009