Search

Cilj ove doktorske disertacije je dobijanje srebro/polivinil-alkohol (Ag/PVA) i srebro/polivinil-alkohol/grafen (Ag/PVA/Gr) nanokompozita elektrohemijskom sintezom nanočestica srebra u PVA rastvoru, odnosno PVA/Gr koloidnoj disperziji. Elektrohemijska reakcija izvodi se pri galvanostatskim uslovima, pri čemu je količinu, oblik i veličinu nanočestica srebra (AgNPs) moguće kontrolisati izborom vrednosti gustine struje i vremena sinteze, te je međusobna zavisnost ovih parametara detaljno ispitana u ovom radu. Svojstva nanokompozita dobijenih u vidu koloidnih disperzija, filmova i hidrogelova ispitane su u cilju potencijalne biomedicinske primene... The goal of this doctoral dissertation is to obtain silver/poly(vinyl alcohol) (Ag/PVA) and silver/poly(vinyl alcohol)/graphene (Ag/PVA/Gr) nanocomposites by electrochemical synthesis of silver nanoparticles (AgNPs) in the PVA solution, or PVA/Gr colloidal dispersion. The electrochemical reaction is performed under galvanostatic conditions, whereby the quantity, shape and size of the silver nanoparticles can be controlled by selecting the value of the current density and the time of the synthesis, and the relation between these parameters is thoroughly examined in this paper. The properties of the nanocomposites obtained in the form of colloidal dispersions, films and hydrogels were examined for potential biomedical application...

Epoksidni nanokompoziti (NK) na bazi diglicidil-etra bisfenola A (DGEBA) pretpolimera i višefunkcionalnog poli(amidoamina) (PAA) kao umreživača su pripremljeni in situ polimerizacijom u prisustvu komercijalnih hemijski modifikovanih montmorijonita (Cloisite®30B; Cloisite®15A) i onih sintetisanih reakcijom jonske izmene sa protonovanim heksadecilaminom (HDA-Mt) i umreživačem (PA-Mt). Pri pripremi NK, 0,5–10 mas.% montmorijonita (Mt) je direktno umešavano sa rastvorom DGEBA, odnosno prethodno dispergovano u pogodnom sistemu rastvarača... Epoxy nanocomposites (CPN) based on diglycidyl ether of bisphenol A (DGEBA) prepolymer and multifunctional poly(amidoamine) (PAA) curing agent were prepared by in situ polymerization in the presence of commercial chemically modified montmorillonites (Cloisite®30B; Cloisite®15A), as well as ones synthesized by ion exchange reaction with protonated hexadecylamine (HDA-Mt) and PAA (PA-Mt). The 0.5–10 wt.% of montmorillonite (Mt) was directly mixed with DGEBA solution or previously dispersed in a suitable solvent system...

U ovoj tezi je ispitana mogućnost sinteze novih, poboljšanih biomaterijala na bazi alginata, agara i cinka, primenom biomimetičkog principa dizajna – biomineralizacije. Cilj istraživanja je bio dizajn i karakterizacija novih nanokompozitnih biomaterijala, sa potencijalnom primenom u biomedicini i pakovanju hrane... The aim of this study was to test the hypothesis whether biopolymer-based biomineralization, with essential metal salts, Zn-minerals, can be considered a good platform for designing nanocomposite biomaterials for potential biomedical and active food packaging applications...

U sredstvima lične balističke zaštite koriste se kompozitni materijali na bazi tkanina velike žilavosti i zatezne čvrstoće, poput aramidnih tkanina impregnisanih polimernim vezivom, uglavnom nekim termoplastičnim ili termoumrežavajućim polimerom. Kompoziti sa nanočestičnim puniocima su perspektivni materijali širokog spektra primene, koji objedinjuju svojstva i prednosti matrice (polimera) i punilaca. Tendencija je da se i u balističkim kompozitnim sistemima postigne maksimum ojačanja, i to uvođenjem nanočestica različitih svojstava i strukture... In the means of personal ballistic protection, composite materials based on fabric of high toughness and tensile strength are used, such as aramid fabrics, impregnated with polymeric binder, mainly some thermoplastic or thermosetting polymer. Composites with nanoparticle fillers are promising materials for a wide range of applications, which combine the properties and benefits of matrix (polymer) and fillers. There is also a tendency in ballistic composite systems to achieve maximum reinforcement by introducing nanoparticles of different properties and structures...

Doktorska disertacija je imala za cilj sintezu i karakterizaciju nanokompozita koji poseduju antimikrobna svojstva inovativnom metodom in situ fotoredukcije Ag+-jona na površini nanokristala TiO2 različitih oblika, prethodno deponovanih na tekstilnim materijalima. Ovakav pristup sintezi nanokompozitnih tekstilnih materijala je po prvi put realizovan u okviru ove teze... This doctoral thesis relates to the synthesis and characterization of advanced nanocomposites which exhibit antimicrobial activity and UV protective properties. For the synthesis an innovative method based on in situ photoreduction of Ag+-ions onto the surface of differently shaped TiO2 nanocrystals, being in the form of either spherical nanoparticles or nanotubes, deposited on different textile materials was applied. Such synthesis route for the formation of textile nanocomposites has been realized for the first time in the context of this thesis...

Doktorska disertacija je imala za cilj sintezu i karakterizaciju nanokompozita koji poseduju antimikrobna svojstva inovativnom metodom in situ fotoredukcije Ag+-jona na površini nanokristala TiO2 različitih oblika, prethodno deponovanih na tekstilnim materijalima. Ovakav pristup sintezi nanokompozitnih tekstilnih materijala je po prvi put realizovan u okviru ove teze... This doctoral thesis relates to the synthesis and characterization of advanced nanocomposites which exhibit antimicrobial activity and UV protective properties. For the synthesis an innovative method based on in situ photoreduction of Ag+-ions onto the surface of differently shaped TiO2 nanocrystals, being in the form of either spherical nanoparticles or nanotubes, deposited on different textile materials was applied. Such synthesis route for the formation of textile nanocomposites has been realized for the first time in the context of this thesis...

U okviru ove doktorske disertacije izvedena je radijaciono-hemijska sinteza i karakterizacija novih nanokompozita na bazi umreţenih polimernih matrica N-izopropilakrilamida (NiPAAm) i itakonske kiseline (IK) i nanočestica srebra (Ag/P(NiPAAm/IK)). Za sintezu nanokompozita je korišćena radiolitička metoda koja omogućava umreţavanje i fino podešavanje svojstava nosača tj. polimerne matrice, ali i formiranje nanočestica srebra ţeljenih svojstava unutar polimerne matrice (in situ sinteza). Radiolitička metoda sinteze je izvedena pod dejstvom gama zračenja na kobaltnom (60Co) izvoru. Sintetisani uzorci su podvrgnuti detaljnoj fizičko-hemijskoj karakterizaciji u cilju dobijanja informacija o polimernim matricama kao nosačima i nanočesticama srebra kao nanopuniocima, ali i u cilju ispitivanja njihovog sinergističkog dejstva u nanokompozitnim sistemima. Morfologija umreţenih sistema je ispitana primenom skenirajuće elektronske mikroskopije (SEM) i mikro kompjuterizovane topografije (mikro-CT), a studija bubrenja praćenjem kinetike bubrenja u medijumima različitih pH-vrednosti i temperature, pri čemu su simulirani fiziološki uslovi. Utvrđeno je da prisustvo itakonske kiseline i inkorporacija nanočestica srebra utiču na morfologiju nanokompozita, parametre polimerne mreţe, kao i na kapacitet bubrenja. Optička svojstva nanokompozita su ispitana metodom spektroskopije u ultraljubičastoj i vidljivoj oblasti spektra (UV-Vis) i teorijskim modelovanjem primenom MiePlot 3.4 programskog paketa čiji je algoritam zasnovan na Mie-ovoj teoriji. U apsorpcionim spektrima je zapaţena karakteristična plazmonska apsorpcija sa maksimumom u opsegu od 390 nm do 412 nm, dok je modelovanjem određeno da se vrednost prečnika nanočestica srebra kreće između 6,8 nm i 16,2 nm... In this study, radiation-chemical synthesis and characterization of the novel nanocomposite systems based on silver nanoparticles (AgNPs) and crosslinked copolymer matrix of N-isopropylacrylamide (NiPAAm) and itaconic acid (IA) (Ag/P(NiPAAm/IA)) were performed. Radiolytic method, which is used for synthesis, enables fine tuning of properties of polymer matrix as a carrier, as well as formation of the silver nanoparticles with desired properties within polymer matrix (in situ synthesis). The radiolytic synthesis method is carried out by gamma irradiation at a cobalt (60Co) radiation facility. Synthesized samples were undergo to detailed physico-chemical characterization in order to obtain information about polymer matrix as a carrier and silver nanoparticles as a nanofillers, but also to examine their synergistic effects in the nanocomposite systems. Morphology of the crosslinked systems was performed by scanning electron microscopy (SEM) and micro computerized topography (micro-CT), while swelling study was performed by monitoring the swelling kinetics in the swelling media with different pH and temperature, i.e. in simulated physiological conditions. It has been shown that the addition of itaconic acid and incorporation of AgNPs have influences on the morphology, network parameters as well as on the swelling capacity. The optical properties of the nanocomposites were investigated by ultraviolet–visible spectroscopy (UV-Vis) and theoretical modeling using MiePlot 3.4 software package, with algorithm based on Mie's theory. Obtained absorption spectra exhibit the characteristic plasmon peak with maxima between 390 nm and 412 nm, while the modeling has shown that the mean size of the silver nanoparticles was in the range between 6.8 nm and 16.2 nm...

U okviru ove doktorske disertacije je izvršena kovalentna funkcionalizacija površine ugljeničnih nanomaterijala primenom dva različita postupka modifikacije. Prvi postupak se zasniva na uvođenju 1,3–dikarbonilnih jedinjenja Bingelovom reakcijom na površinu višeslojnih ugljeničnih nanocevi (MWCNT), dok su u drugom postupku na površinu MWCNT i grafena uvedene kiseonične funkcionalne grupe plazmom dobijenom pomoću dielektričnog barijernog pražnjenja (DBD) na atmosferskom pritisku. U daljem toku istraživanja su pripremljeni nanokompoziti funkcionalizovanih MWCNT sa amorfnim polimerom poli(metil metakrilatom) (PMMA) i elektroprovodnim polianilinom (PANI). Na grafensku površinu MWCNT su preko ciklopropanskog prstena uvedna 1,3– dikarbonilna jedinjenja primenom dve metode funkcionalizacije koje se zasnivaju na Bingelovoj reakciji. Prva metoda podrazumeva direktno uvođenje dietil malonata, barbiturne kiseline, dimedona i 2,2–dimetil–1,3–dioksan–4,6-diona na površinu nanocevi Bingelovom reakcijom. U drugom postupku, površina MWCNT–a najpre je modifikovana dietil malonatom, a potom su izvedene reakcije sinteze (zatvaranja prstena) barbiturne i tiobarbiturne kiseline sa ureom, odnosno tioureom. Ciklopropanski prsten na površini nanocevi ne narušava inherentnu grafensku strukturu nanomaterijala što se ispoljava u značajnom poboljšanju električnih svojstava i malim vrednostima poluprovodničke površinske otpornosti funkcionalizovanih MWCNT, naročito nakon dejstva električnog polja na disperziju nanomaterijala u rastvarču uz zagrevanje do 80°C. Funkcionalizovane MWCNT su pokazale bolja disperzibilna svojstva i prisustvo 1,3–dikarbonilnih jedinjenja je učinilo površinu nanocevi hidrofilnijom i pristupačnijom za prilaz elektrolita što je rezultovalo povećanom kapacitivnošću Au/MWCNT elektroda. Optimizovana je geometrija 1,3–dikarbonilnih jedinjenja na površini MWCNT semi–empirijskim proračunima (PM6) i određen je molekulski elektrostatički potencijal (MEP) ... Covalent sidewall functionalization of carbonaceous nanomaterials was performed using two modification procedures. The first procedure was functionalization of multiwalled carbon nanotubes (MWCNTs) based on the Bingel reaction, while in the second procedure, MWCNT and graphene nanoplatelets (GNPs) were functionalized by dielectric barrier discharge (DBD) in air. Sidewall functionalization of multiwalled carbon nanotubes (MWCNTs) by Bingel reaction was performed using two approaches. In the first approach, a 1,3- dicarbonyl compound (barbituric acid, dimedone, diethyl malonate and 2,2-dimethyl- 1,3-dioxane-4,6-dione) was directly attached to the surface of carbon nanotubes under the Bingel reaction conditions. In the second approach, the surface of MWCNTs was firstly modified by diethyl malonate as a precursor and its subsequent cyclization to barbituric and thiobarbituric acid was accomplished with urea and thiourea, respectively. The results revealed that functionalized MWCNTs demonstrated enhanced electrical properties and significantly lower sheet resistance, especially after electric field thermal assisted annealing at 80°C. The presence of 1,3-dicarbonyl compounds caused the surface of MWCNTs to be more hydrophilic, approachable to the electrolyte solution and improved the capacitance performance of Au/MWCNTs electrodes. The geometry optimization of 1,3-dicarbonyl compounds on the MWCNTs surfaces was performed using semi–empirical calculation (PM6). The second part of the thesis was focused on MWCNTs and graphene nanoplatelets functionalization by dielectric barrier discharge (DBD) in air. The extent of functionalization of MWCNTs and GNPs reaches a maximum at the delivered discharge energy of 720 and 240 J mg–1, respectively. Further exposure to plasma leads to reduction of functional groups from the surface of the treated nanomaterials. It was also demonstrated that introduction of oxygen functionalities by DBD plasma treatment does not produce dramatic structural changes in MWCNTs and GNPs structure..

Cilj ove doktorske disertacije je elektrohemijsko dobijanje i karakterizacija nanokompozitnih sistema srebro/poli(N-vinil-2-pirolidon) (Ag/PVP), i srebro/alginat (Ag/alginat), u obliku koloidnih disperzija i hidrogelova, za biomedicinsku primenu. Elektrohemijska sinteza, u odnosu na hemijsku, pokazuje prednost u dobijanju malih čestica metala visoke čistoće, i to sa manjim brojem hemikalija, što je od izuzetnog značaja za primenu u biomedicini. Takođe, elektrohemijska sinteza daje mogućnost precizne kontrole veličine nanočestica, podešavanjem vrednosti gustine struje ili potencijala. Izvršena je optimizacija elektrohemijske sinteze nanočestica srebra u rastvorima PVP i alginata. Dobijene Ag/PVP i Ag/alginatne koloidne disperzije su karakterisane različitim fizičko-hemijskim metodama radi izbora najefikasnijeg režima i uslova sinteze. U cilju dobijanja što veće koncentracije nanočestica, sfernog oblika, ispitan je uticaj potencijala, gustine struje, vremena implementacije, sastava rastvora za sintezu. Sastav, morfologija i struktura nanokompozitnih sistema su ispitani UV-vidljivom spektroskopijom, optičkom, transmisionom i skenirajućom elektronskom mikroskopijom, cikličnom voltametrijom, spektroskopijom infracrvene svetlosti sa Furijeovom (Fourier) transformacijom (FT-IR). Elektrohemijska sinteza nanočestica srebra u rastvoru PVP je vršena u galvanostatskim i potenciostatskim uslovima, kao i primenom reversne struje. Utvrđeno je da galvanostatska sinteza obezbeđuje veću koncentraciju dobijenih nanočestica, koja raste sa povećanjem primenjene gustine struje. Najveća koncentracija nanočestica srebra dobijena je galvanostatskom sintezom, gustinom struje od 62 mA cm-2, tokom 10 min. Veličina dobijenih nanočestica je oko 75 nm. FT-IR spektroskopijom je utvrđeno da se interakcija između molekula PVP i nanočestica srebra dešava ili na atomu azota ili na atomu kiseonika u pirolidonskom prstenu (u zavisnosti od veličine nanočestica) koordinacionim vezama sa nanočesticama srebra. Dobijeni rezultati ukazuju na vezivanje molekula PVP sa Ag nanočesticama, što potvrđuje... The objective of this doctoral dissertation is the electrochemical synthesis and characterization of silver/poly(N-vinyl-2-pyrrolidone) (Ag/PVP), and silver/alginate (Ag/alginate), nanocomposite systems, in forms of colloid dispersions and hydrogels, for biomedical purposes. The electrochemical synthesis, in comparison with the chemical, exhibits the advantages in obtaining of small metal nanoparticles of high purity, using smaller number of chemicals. This becomes of a great importance in biomedical applications. Electrochemical synthesis also gives a possibility of a precise particle size control, by the adjustment of the applied current density or potential. The optimization of the electrochemical synthesis of silver nanoparticles in PVP and alginate solutions was performed. As obtained Ag/PVP and Ag/alginate colloid dispersions were characterized by various physico-chemical methods in order to find the most efficacious regime and conditions of the synthesis. Aiming the highest possible nanopartcle concentration, the influence of the applied potential, current density, implementation time and the synthesis solution composition were examined. The composition, morphology and the structure of nanocomposite systems were investigated by UV-visible spectroscopy, optic, transmission and scanning electron microscopy, cyclic voltammetry and Fourier transform infrared spectroscopy (FT-IR). The electrochemical synthesis of silver nanoparticles inside PVP solution was performed in galvanostatic and potentiostatic conditions, as well as by using a reverse current. It is determined that the galvanostatic synthesis provides higher concentration of the obtained silver nanoparticles, increasing with the increase of the applied current density. So, the highest concentration of silver nanoparticles is obtained galvanostatically, at the applied current density of 62 mA cm-2, during 10 min. The size of the obtained silver nanoparticles was ~75 nm. FT-IR spectroscopy results showed the interaction between PVP...

Titania (TiO2) due to its photocatalytic activity, chemical and biological inertness, resistance to chemical- and photo-corrosion, non-toxicity, and relatively low cost, is one of the most studied semiconductors for environmental protection, selfcleaning, deodorizing, sterilizing and renewable energy sources. Owing to its wide band gap and high speed of electron/hole recombination, the efficiency of photocatalysts based on TiO2 is however small for potential practical applications. In the last four decades, much effort has been invested in research related to improving the photocatalytic efficiency of TiO2 and its possible practical applications. Generally, the photocatalytic efficiency of TiO2 can be increased by: (1) reducing the band gap energy by doping and/or enlargement of its absorption in the visible region using photosensitizes, (2) improving the separation (reducing the recombination rate) of photogenerated charge carriers (electron/hole) and (3) increasing the specific surface area and the quality of the active sites (for adsorption of pollutants to be photocatalytically degraded). The aim of this doctoral dissertation was the study of the process of the formation of undoped and doped nanostructured powders and thin films of titanium(IV) oxide with significantly enhanced photocatalytic efficiency. To this end, in order to obtain high photocatalytic activity in the visible light region, it was therefore mandatory to generate active visible light absorption centers. Anion doping proved itself to process great potential in inducing such absorption, and intensive efforts have been directed towards the development of methods for synthesizing anion-doped titania-based photocatalysts with a large visible light response. Therefore, in this doctoral thesis, first pulsed laser deposition of TiO2 films on glass substrates under oxygen, methane, nitrogen and mixture of oxygen and nitrogen atmospheres is presented. Nitrogen incorporation into the TiO2 lattice was successfully achieved, as demonstrated by optical absorption and XPS measurements. The absorption edge of the N-doped TiO2 films was red-shifted by ≈480 nm from the undoped value of 360 nm. The photocatalytic activity of TiO2 films was investigated during toxic Cr(VI) ions photoreduction to the Cr(III) state in aqueous media under irradiation with visible and UV light. Under visible light irradiation, the TiO2 films deposited under a nitrogen atmosphere showed the highest photocatalytic activity, whereas on UV light exposure, the best results were obtained for the TiO2 structures deposited under a pure methane or oxygen atmosphere... Titan(IV)-oksid (TiO2) je zbog svoje fotokatalitičke aktivnosti, hemijske i biološke inertnosti, otpornosti na fotoindukovanu i hemijsku koroziju, netoksičnosti i relativno niske cene, jedan od najčešće proučavanih poluprovodničkih materijala za primenu u dekontaminaciji životne sredine, samo-čišćenju, uklanjanju mirisa, sterilizaciji i obnovljivim izvorima energije. Zbog široke zabranjene zone i velike brzine rekombinacije fotogenerisanih parova elektron-šupljina, efikasnost fotokatalizatora na bazi TiO2 je i dalje mala za potencijalnu praktičnu primenu. U poslednje četiri decenije veliki napor je uložen u istraživanja vezana za poboljšanje fotokatalitičke efikasnosti TiO2 i njegovu moguću praktičnu primenu. Generalno, fotokatalitička efikasnost TiO2 se može povećati: (1) smanjenjem energije zabranjene zone dopiranjem i/ili proširenjem apsorpcije (u vidljivu oblast) upotrebom fotosenzitizera, (2) poboljšanjem razdvajanja (smanjenjem brzine rekombinacije) fotogenerisanih nosilaca naelektrisanja (elektron/šupljina) i (3) povećanjem specifične površine i kvaliteta aktivnih mesta (za adsorpciju polutanata koje je potrebno fotokatalitički razgraditi). Cilj ove doktorske disertacije je proučavanje procesa formiranja nedopiranih i dopiranih nanostrukturnih prahova i tankih filmova titan(IV)-oksida znatno poboljšane fotokatalitičke efikasnosti. Da bi se postigla visoka fotokatalitička aktivnost u vidljivoj oblasti, neophodno je generisati aktivne apsorpcione centre za vidljivu svetlost. Pokazalo se da dopiranje anjonima nemetala predstavlja veliki potencijal u indukovanju takve apsorpcije i dosta napora se ulaže u razvijanje metoda za sintezu anjon-dopiranih TiO2 fotokatalizatora sa visokom aktivnošću u vidljivom delu spektra. Prema tome, u ovoj doktorskoj disertaciji prvo je predstavljeno dobijanje TiO2 filmova pulsnom laserskom depozicijom na staklenim supstratima u atmosferi kiseonika, metana, azota i mešavini kiseonika i azota. Inkorporacija azota u rešetku TiO2 je uspešno ostvarena, što je i pokazano merenjem optičke apsorpcije i fotoelektronske spektroskopije X-zracima (XPS). Apsorpciona ivica N-dopiranih TiO2 filmova pokazuje crveni pomeraj do ~480 nm u odnosu na 360 nm u slučaju nedopiranih filmova. Fotokatalitička aktivnost TiO2 filmova ispitivana je u reakciji fotoredukcije toksičnih Cr(VI) u Cr(III) jone u vodenoj sredini uz ozračivanje vidljivom i UV svetlošću. Najveću fotokatalitičku aktivnost u prisustvu vidljive svetlosti pokazuju TiO2 filmovi deponovani u atmosferi azota, dok su u prisustvu UV svetlosti najbolji rezultati dobijeni za TiO2 filmove deponovane u atmosferi čistog metana i kiseonika...

U ovoj doktorskoj disertaciji opisana je kovalentna funkcionalizacija višeslojnih ugljeničnih nanocevi (multi-walled carbon nanotubes, MWCNT) pomoću amina. Funkcionalizacija je izvršena hemijskom modifikacijom karboksilnih grupa koje su uvedene na površinu nanocevi metodom oksidacije u smeši koncentrovanih kiselina. MWCNT su funkcionalizovane etilendiaminom (EDA), 1,6-heksandiaminom (HDA), dietilentriaminom (DETA), trietilentetraaminom (TETA) i 1,4-fenilendiaminom (PDA) pomoću O-(7- azabenzotriazol-1-il)-N,N,N',N'-tetrametiluronium heksafluorofosfata (N-HATU) i N,Ndiizopropiletilamina (DIEA). Kuplujući agens N-HATU omogućuje veću brzinu reakcije funkcionalizacije u odnosu na postojeće metode sinteze amida. Dobijeni uzorci su karakterisani različitim tehnikama, kao što su: FTIR, XRD, elementarna analiza, TGA, SEM, TEM, STM, UV-vis spektroskopija i ciklična voltametrija. MWCNT funkcionalizovane sa PDA i EDA poseduju najbolja disperzibilna i elektrohemijska svojstva. Funkcionalizovane MWCNT, u koncentracijama od 1 do 50 μg/ml, nisu citotoksične za fibroblastnu, L929 ćelijsku liniju. Međutim, koncentracije MWCNT veće od 10 μg/ml smanjuju rast ćelija i u tom smislu ovaj nalaz je u pozitivnoj korelaciji sa stepenom njihove internalizacije od strane L929 ćelija. U okviru ove disertacije prikazano je uklanjanje kadmijuma iz vodenih rastvora pomoću netretiranih višeslojnih ugljeničnih nanocevi (n-MWCNT), oksidovanih (o- MWCNT) i etilendiaminom funkcionalizovanih (e-MWCNT). U šaržnim uslovima ispitan je uticaj pH vrednosti rastvora, kontaktnog vremena, početne koncentracije metala i temperature na sorpciju Cd2+ jona na n-MWCNT, o-MWCNT i e-MWCNT. Adsorpcija Cd2+ jona na o- MWCNT i e-MWCNT izrazito zavisi od pH vrednosti rastvora. Vremenski zavisna adsorpcija Cd2+ jona na n-MWCNT, o-MWCNT i e-MWCNT opisana je pomoću kinetičkog modela pseudo drugog reda. Model Langmuirove izoterme najbolje fituje dobijene eksperimentalne ravnotežne podatke. Maksimalni kapacitet od 25,7 mg/g, na 45 °C, dobijen je za e-MWCNT. Termodinamički parametri su takođe, izračunati za adsorpciju Cd2+ jona na n-MWCNT, o- MWCNT i e-MWCNT i rezultati pokazuju da je proces adsorpcije spontan i endoterman. Kovalentna amino-funkcionalizacija MWCNT prikazana je kao pogodan metod za poboljšanje mogućnosti daljeg procesiranja MWCNT. Upotrebom funkcionalizovanih nanocevi dobijeni su homogeni i transparentni kompoziti, na bazi MWCNT i poli(metil metakrilata) (PMMA). Kovalentna veza, koja se formira između amino-funkcionalizovanih MWCNT i PMMA, poboljšava disperziju MWCNT u polimeru kao i električna i mehanička svojstva kompozita... Since their discovery in 1991 by Iijima, carbon nanotubes (CNTs) have attracted great interest in most areas of science and engineering due to their unique physical and chemical properties, which enable them to be applied for a wide range of applications. However, the application of CNTs has been largely hampered by their poor dispersion into solvents or polymers due to the strong intermolecular van der Waals interactions among the nanotubes, which can lead to the formation of aggregates. A common technique to improve dispersion and realize such a great capability of CNTs is through chemical functionalization, which enables chemical covalent or non-covalent bonding between the CNTs and material of interest. The covalent side-wall modifications of nanotubes, in general, include: (i) amidation or esterification of carboxylated CNTs, (ii) side-wall covalent attachment of functional groups directly to the pristine CNTs. Among them, amino-functionalized CNTs have been investigated because amino group has a high reactivity, and can react with many chemicals, such as polymers, and biological components. Amino-functionalization was also employed and studied in this work. Modified CNTs were examined toward different applications described below. Surface functionalization of multi-walled carbon nanotubes (MWCNTs), with amino groups via chemical modification of carboxyl groups introduced on the nanotube surface, using O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (NHATU) and N,N-diisopropylethylamine (DIEA) was reported. The N-HATU coupling agent provides faster reaction rate and the reaction occurs at lower temperature compared to amidation and acylation-amidation chemistry. The amines, ethylenediamine (EDA), 1,6- hexanediamine (HDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and 1,4- phenylenediamine (PDA) were used. The resulting materials were characterized with different techniques such as FTIR, XRD, elemental analysis, TGA, SEM, TEM, STM, UV-vis spectroscopy and cyclic voltammetry. MWCNTs functionalized with PDA and EDA posses the best dispersibility and electron transfer properties in comparison to the others amines. Functionalized MWCNTs, at the concentrations between 1 and 50 μg/ml, were not cytotoxic for the fibroblast L929 cell line. However, the concentrations of MWCNTs higher of 10 μg/ml reduced cell growth and this effect correlated positively with the degree of their uptake by L929 cells. In batch tests, the influences of solution pH, contact time, initial metal ion concentration and temperature on the sorption of Cd2+ ions onto raw MWCNTs (raw- MWCNT), oxidized MWCNTs (o-MWCNT) and EDA-functionalized MWCNTs (e- MWCNT) were studied. The adsorption of Cd2+ ions by o-MWCNT and e-MWCNT was strongly pH-dependent. The time dependent Cd2+ sorption onto raw-MWCNT, o-MWCNT and e-MWCNT can be described by a pseudo-second-order kinetic model. The Langmuir isotherm model agrees well with the equilibrium experimental data. The maximum capacity was obtained for e-MWCNT, 25.7 mg/g, at 45 °C. The thermodynamic parameters were also deduced for the adsorption of Cd2+ ions on raw-MWCNT, o-MWCNT and e-MWCNT and the results showed that the adsorption was spontaneous and endothermic. In this study was shown that covalent amino-functionalization of MWCNTs was a powerful method for enhancing the ability to process MWCNTs and facilitating the preparation of homogenous, coherent and transparent MWCNT/Poly(methyl methacrylate) (PMMA) composites. Covalent bond formation between amino-functionalized MWCNTs and PMMA enhanced the MWCNTs dispersion in polymer and improved electrical conductivity and mechanical properties of the composite...