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Ibuprofen and diclofenac sodium adsorption onto functionalized minerals: Equilibrium, kinetic and thermodynamic studies
No full textCationic surfactant - octadecyldimethylbenzyl ammonium chloride (ODMBA) was used for modification of the three natural raw materials - bentonite, kaolin and zeolite. Adsorption of ODMBA by minerals occurred via ion exchange of inorganic cations on minerals with surfactant. Organomodified minerals - organobentonite (OB), organokaolin (OK) and organozeolite (OZ) were studied as adsorbents for removal of two non-steroidal anti-inflammatory drugs - ibuprofen (IBU) and diclofenac sodium (DS) at pH 7. For all systems, the pseudo-second order model showed the best correlation to kinetic experimental data. In all cases, the positive values of Delta H degrees indicated that the adsorption of both IBU and DS by organomodified minerals was endothermic in nature. Equilibrium data were better described by the Freundlich isotherm model, pointing to adsorbent heterogeneous active sites for adsorption. Under applied experimental conditions, the highest adsorption of both drugs was achieved by OB, while much lower capacities were observed for OK and OZ. Nonlinear isotherms and physicochemical characterization of organomodified minerals after drugs adsorption suggested complex mechanism consisting of hydrophobic interactions between hydrophobic part of the drugs and surfactants alkyl chains, electrostatic interactions of anionic forms of IBU and DS with the cationic "head" of ODMBA, as well as anion exchange of counterion ions from ODMBA micelle and anionic forms of both drugs. Adsorption of both IBU and DS was strongly dependent on the amount of ODMBA ions in the minerals
Kompozitne bioaktivne prevlake sa gentamicinom elektroforetski taložene na titanu / Composite bioactive coatings loaded with gentamicin electrophoretically deposited on titanium
No full textMultifunkcionalni i višekomponentni biomaterijali se cesto primenjuju u rekonstruktivnoj
hirurgiji zbog sposobnosti da pospešuju osteointegraciju, istovremeno omogucavajuci
primenu antibakterijskih agenasa direktno na mestu intervencije. Primenom
elektroforetskog taloženja, iz cetvorokomponentne vodene suspenzije (hidroksiapatit,
poli(vinilalkohol), hitozan i gentamicin) dobijene su, u jednom koraku, bioaktivne i
antibakterijske kompozitne prevlake na titanu. Karakterizacija prevlaka je izvršena
primenom rendgenske difrakcione analize (XRD), infracrvene spektroskopije sa
Furijeovom transformacijom (FTIR) i skenirajuce elektronske mikroskopije (SEM).
Pracenjem kinetike antibakterijske aktivnosti u suspenziji potvr ena je antibakterijska
efikasnost prevlake sa gentamicinom. Prema dobijenim rezultatima moguce je zakljuciti da
dobijene kompozitne prevlake sa gentamicinom predstavljaju uspešan biomaterijal za
potencijalnu primenu u biomedicini.Multifunctional and multicomponent biomaterials are very often the material of choice in
reconstructive surgery, having the ability to promote osteointegration, allowing the
antibacterial agents application directly at the site of intervention. Single-step
electrophoretic deposition was employed to assemble bioactive and antibacterial composite
coatings on titanium, from a four-component aqueous suspension (hydroxyapatite,
poly(vinyl alcohol), chitosan and gentamicin). Physico-chemical characterization of the
coatings was performed using X-ray diffraction (XRD), Fourier transform infrared
spectroscopy (FTIR) and scanning electron microscopy (SEM). Antibacterial activity of
gentamicin loaded coating was confirmed by antibacterial activity kinetics in suspension.
According to the obtained results, it can be concluded that composite coating loaded with
gentamicin represents a successful biomaterial for possible application in biomedicine
Pelleting process, required equipment and benefits of use
No full textPelletizing, not to be confused with pelleting (extrusion), continues to see increasing use across industries for the many benefits it can offer to previously difficult-to-handle bulk solids and fines.
Here’s an inside look at the principles behind this process, the equipment used, and the many benefits producers can gain from pelletizing their material
Review of world patents and domestic solutions of sustainable development and water security
No full textWe are witnessing increasingly rapid and pronounced climate changes caused not only by natural processes, but also by increasing environmental pollution, which is a direct consequence of human activity. Population growth as well as technological and economic progress have a negative impact on the environment, and in recent decades, sustainable development and water security have been imposed as inevitable in solving the water-food-energy relationship. Water safety is the primary task in the project to mitigate the impact of environmental pollution at all world levels of structures. In 2015, the United Nations, with its 193 members, revised the agenda planned for 2030, which consists of 17 goals that are primary in the future, including social inclusion, environmental sustainability, justice, peace, economic development, good governance and partnership. One of the main goals of sustainable development is the central focus, and it refers to clean water and sanitation. This paper provides an overview of some global trends in wastewater treatment in relation to domestic methods of mine water purification. In the continuation of the research, the goal of the work was the valorization of man-made mineral raw materials (secondary sulfur and fly ash), which creates an environmentally acceptable and useful material from the mentioned ecologically hazardous substances, mass applicable primarily in construction, but also elsewhere. In addition, the project is focused on the removal of heavy metals from acid mine wastewater using pelletized fly ash as a sorbent that will be further used for the synthesis of sulfur concrete. The production of sulfur concrete implies the use of secondary sulfur from oil refining as a substitute for Portland cement binder in conventional concrete, which achieves a significant environmental and economic benefit.
The project includes several aspects useful in Europe and the world, such as obtaining new materials and using waste resources, which has a very important impact on environmental protection, as well as an important economic aspect. Since these fields are relatively young, their further development and application of the obtained results in the industry is expected in the future
Antibacterial activity of surface amine-functionalized silver-enriched zeolite
No full textNatural zeolite-clinoptilolite (from Vranjska Banja deposit in Serbia) and synthetic Beta zeolite,
were amin-functionalized using (3-aminopropyl)-triethoxysilane (APTES). The results of the
Fourier transform infrared spectroscopy and thermogravimetric analysis confirmed the presence of
amino groups derived from APTES onto the modified zeolite surface. APTES-enriched zeolite was
further used as an adsorbent of silver ions from aqueous solutions. Natural zeolite-clinoptilolite
showed a higher adsorption capacity (96 mg Ag/g), compared to beta zeolite (54 mg Ag/g) which is
attributed to the presence of exchangeable cations in the structure of clinoptilolite. The kinetic data
follows the pseudo-second-order model which indicates a chemical interaction between silver ions
and functional amino groups on the surface of the zeolite. Ag-APTES and APTES-enriched zeolites
further were studied as antibacterial agents toward the pathogenic bacteria Gram-negative
Escherichia coli DSM 498 and Gram-positive Staphylococcus aureus ATCC 25923. Based on the
results, it was concluded that the APTES-zeolites do not exhibit antibacterial activity while Ag-
APTES enriched zeolites shows antibacterial effect toward both examined bacterial strains.
Antibacterial activity is attributed to the presence of silver ions
Testing of mechanical properties of bitumen products obtained using polyethylene tereftalate-based plastifiers
No full textPredmet ovog istraživanja je sinteza glikolizata iz recikliranog poli(etilen tereftalata) (PET) postupcima depolimerizacije pomoću dietilenglikoala (DEG) u prisustvu katalizatora FASCAT 4100. Dobijeni glikolizat je zatim tretiran anhidridom maleinske kiseline i na kraju 2-oktanolom (2-EtHex pri čemu se dobija 2-EtHex/MA/DEG/PET/EG/MA/2-EtHex plastifikator. Karakterizacija dobijenog plastifikatora izvršena je infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR) i NMR spektroskopijom. Dobijeni plastifikatori (10 tež. %) su umešani u bitumen a zatim u su izvršena ispitivanja mehaničkih svojstava dobijenih proizvoda.The subject of this study is the synthesis of glycolysates from recycled poly (ethylene terephthalate) (PET) by depolymerization using diethylene glycol (DEG) in the presence of catalyst FASCAT 4100. The resulting glycolysate was then treated with maleic anhydride and finally with 2-octanol to obtain a 2-EtHex/MA/DEG/PET/EG/MA/2-EtHex plasticizer. The characterization of the obtained plasticizer was performed by infrared spectroscopy with Fourier transform (FTIR) and NMR spectroscopy. The obtained plasticizers were mixed into bitumen with 10 wt. % and tests of mechanical properties of obtained products were performed
Fire-resistant composites based on acrylic-functionalized lignin and polyester resin obtained from waste poly(ethylene terephthalate)
No full textU ovom radu ispitivan je potencijal korišćenja akril-funkcionalizovanog kraft lignina (AKL) u smanjenju zapaljivosti polimernih kompozita na bazi recikliranih nezasićenih poliesterskih smola (NZPS). Akrilna funkcionalizacija kraft lignina je izvedena direktnom esterifikacijom slobodnih polifenolnih grupa sa akriloil hloridom, nakon čega je AKL umešan u NZP smolu sintetizovanu od poliola dobijenih katalitičkom depolimerizacijom otpadnog poli(etilen tereftalata). AKL je homogenizovan sa NZPS pri različitim masenim udelima: 2,5, 5,0, 7,5 i 12,5 mas.%. Strukturne i dinamičko-mehaničke karakteristike akril-funkcionalizovanog kraft lignina i kompozita određene su primenom FTIR spektroskopije, dinamičkomehaničke analize (DMA) i testova jednoosnog zatezanja. Proučavan je uticaj funkcionalizacije i masenog udela AKL na zatezna i termička svojstva NZPS. Vatrootporna svojstva kompozita su ispitivana prema standardnoj UL-94V metodi, na osnovu koje je kompozit sa 12,5 tež. % akril-funkcionalizovanog lignina dostigao najvišu kategorija toplotno otpornih materijala.This paper investigates the using potential of acryl-functionalized kraft lignin (AKL) in reducing the flammability of polymer composites based on recycled unsaturated polyester resins (UPR). Acryl functionalization of kraft lignin was performed by direct esterification of free polyphenolic groups with acryloyl chloride, after what, the AKL was blended in UPR resin synthesized from the polyols obtained by catalytic depolymerization of waste poly(ethylene terephthalate). The AKL was homogenized in UPR resin in different weight ratios: 2.5, 5.0, 7.5, and 12.5 wt.%. Structural and dynamic-mechanical characteristics of acryl-functionalized kraft lignin and composites were determined using FTIR spectroscopy, dynamicmechanical analysis (DMA), and tensile tests. The influence of functionalization and mass fraction of AKL on tensile and thermal properties of UPR resin was studied. The thermal properties of the composite were tested according to the standard UL-94 method, based on which the highest category of heat-resistant materials is a composite with 12.5 wt.% acylfunctionalized lignin
Sustainable development and natural resources exploitation: Brief review
No full textNatural resources are limited and uncontrolled exploitation can have negative effects on the environment. It is necessary to find approach of their sustainable use. Sustainable development is the framework for defining strategies of continuous state and social progress, without harm to the environment and natural resources essential for human activities in the future. Model that regulates sustainable use considers strategies and legal regulations for exploitation of natural resources and energy. Goal is to ensure the sustainable use of natural resources at national and global level. Sustainable use of natural resources is directly related to environmental protection. Also, the preservation of the working and living environment is related to the degree of economic development and the level of education of the population about the importance of a healthy environment and the way of its preservation. Accelerated technological development leads to an improvement in the quality of life in all spheres of human activity, but in parallel, it creates the possibility of greater environmental degradation. Therefore, it is necessary, within the goals of the development policy of the society, to include the correct criteria that will contribute to sustainable development. Thus, we contribute to preserving the environment and balance of natural ecosystems
Listvenite as gemstone: the Antina Čuka occurrence (Eastern Serbia)
No full textAntina Čuka listvenite originated by hydrothermal alteration of small ophiolite mass caused by Paleogene magmatic activity. Mineralogical and petrological examination of the listvenite revealed serpentine-rich, silica-rich, and carbonate-rich varieties of the listvenite. Typical minerals are serpentine (group), carbonates (calcite, dolomite, and magnesite), pyrite, gersdorffite, Cr-spinel, barite, limonite, and native Ag. Gemological analysis revealed all serpentine varieties from Antina Čuka (serpentine-rich listvenite, serpentine-rich listvenite with magnetite and fresh serpentinite) have values of both refractive index and specific gravity in the range for serpentine group minerals. A Refractive index value of 1.54 for silica-rich variety confirms the presence of quartz. The results of lapidary processing have proven that both listvenite from Antina Čuka and serpentinite host rock are attractive gemstones. The adequate types of processing of Antina Čuka listvenite are plain cut (different-shaped cabochons) and glyptography/carving