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    Influence investigation of different parameters on photocatalytic degradation of procaine

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    Farmaceutici su sveprisutni u našem svakodnevnom životu i time vrlo lako dospijevaju u okoliš. Primarni put njihovog ulaska u okoliš je kroz izvore otpadnih voda. Farmaceutici i njihovi metaboliti koji se prenose otpadnom vodom u rijeke i potoke uzrokuju velike probleme u cijelom ekosustavu i vrlo ju je važno prije ispuštanja u vodotokove adekvatno obraditi. Konvencionalni biološki i kemijski postupci obrade otpadnih voda su neučinkoviti zbog bio-nerazgradive prirode mnogih farmaceutika pa se stoga istražuju napredni oksidacijski procesi. Kao jedan od naprednih oksidacijskih procesa u ovom se radu provodi fotokataliza uz katalizator koji je napravljen nanošenjem TiO2 filma na Al2O3 keramičku, pjenastu podlogu pri čemu je kao izvor zračenja korištena UV lampa. U ovom radu ispitan je utjecaj različitih parametara na fotokatalitičku razgradnju prokaina. Prvo je provedena validacija metode za praćenje prokaina u vodi. Nakon toga proveli su se preliminarni eksperimenti kojima se potvrdilo da smanjenje koncentracije prokaina u otopini nije povezano s njegovom hidrolitičkom razgradnjom niti njegovom adsorpcijom na fotokatalizator. Također, određena je i kinetika fotokatalitičke razgradnje prokaina koja se može opisati reakcijom razgradnje prvog reda. Nadalje, provođenjem eksperimenata kojima se ispitao utjecaj pH vrijednosti otopine i koncentracije prokaina određeni su optimalni uvjeti za provođenje fotokatalitičke razgradnje pri čemu koncentracija prokaina iznosi 10 mg/L, a pH vrijednost otopine 10. Ispitivanjem utjecaja slobodnih radikala na mehanizam razgradnje pokazalo se da šupljine imaju značajnu ulogu. Prilikom ispitivanja utjecaja matice vode utvrđeno je da nitrati i kloridi blago usporavaju fotokatalitičku reakciju razgradnje prokaina, a hidrogenkarbonati povećavaju brzinu razgradnje, ali sama promjena koncentracije navedenih tvari u otopini ne utječe na brzinu razgradnje. S druge strane, povećanjem koncentracije huminske kiseline smanjuje se brzina fotokatalitičke razgradnje. Razgradni produkti određeni nakon provođenja eksperimenta pri optimalnih uvjetima su RP-1 s m/z 120 i RP-2 s m/z 138. Na kraju se provela i procjena razvojne toksičnosti, mutagenosti i bioakumulacijskog faktora prokaina i nastalih razgradnih produkata računalnim programom TEST.Pharmaceuticals are ubiquitois in our daily lives and therefore easily enter the environment. They enter the environment primarly through wastewater. Pharmaceuticals and their metabolites that enter rivers and streams with wastewater are a major problem for the entire ecosystem, and it is very important to treat them properly before they enter waterways. Conventional biological and chemical wastewater treatment methods are ineffective due to the biodegradability of many pharmaceuticals, so advanced oxidation methods are being researched. As one of the advanced oxidation methods, photocatalysis is carried out in this work with a catalyst prepared by depositing a TiO2 film on an Al2O3 ceramic foam substrate, using a UV lamp as a radiation source. In this work, the influence of various parameters on the photocatalytic degradation of procaine was investigated. First, the validation of the method for monitoring procaine in water was carried out. Then, preliminary experiments were performed, which confirmed that the decrease of procaine concentration in solution was not related to its hydrolytic degradation or adsorption to the photocatalyst. Moreover, the kinetics of the photocatalytic decomposition of procaine was determined, which can be described by a first-order decomposition reaction. In addition, experiments that investigated the influence of solution pH value and the procaine concentration, the optimal conditions for carrying out photocatalytic decomposition, where the procaine concentration is 10 mg/L and the solution pH is 10. When studying the influence of free radicals on the decomposition mechanism, it was found that the holes played an important role. When the influence of water matrix was studied, it was found that nitrates and chlorides slightly slow down the photocatalytic reaction of procaine decomposition and hydrogen carbonates increase the rate of decomposition, but the mere change of the concentration of the mentioned substances in the solution does not affect the rate of decomposition. Increasing the concentration of humic acid, on the other hand, decreases the photocatalytic degradation rate. The degradation products determined after performing the experiment under optimal conditions are RP-1 with m/z 120 and RP-2 with m/z 138. Finally, an evaluation of the developmental toxicity, mutagenicity, and bioaccumulation factor of procaine and the resulting degradation products was performed using the computer program TEST

    Impact of structural features on mechanical flexibility of crystals of one-dimensional cadmium(II) polymers with halides and pyridine and pyrazine derivatives

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    U ovom diplomskom radu sintetizirani su koordinacijski polimeri kadmijevih(II) halogenida s 2-metilpirazinom (2-Mepz), 3-metilpiridinom (3-Mepy) i 4-metilpiridinom (4-Mepy). Devet kompleksnih spojeva ([CdCl2(2-Mepz)]n (1), [CdBr2(2-Mepz)]n (2), [CdI2(2-Mepz)]n (3), [CdCl2(3-Mepy)2]n (4), [CdBr2(3-Mepy)2]n (5), [CdI2(3-Mepy)2] (6), [CdCl2(4-Mepy)2]n (7), [CdBr2(4-Mepy)2]n (8) i [CdI2(4-Mepy)2]n (9)) priređeno je klasičnom otopinskom sintezom, a njihovi jedinični kristali uzgojeni su tehnikom nadslojavanja. Spojevi su analizirani metodama termičke analize (TGA, DSC), infracrvenom spektroskopijom (IR) te difrakcijom rendgenskog zračenja u praškastom uzorku (PXRD), a metodom difrakcije rendgenskog zračenja u monokristalnom uzorku (SCXRD) analizirani su igličasti kristali. Također je ispitan i odziv igličastih kristala priređenih spojeva na primjenu vanjske mehaničke sile te je u slučaju elastično savitljivih kristala odziv i kvantificiran. U kristalnom pakiranju ustanovljene su supramolekulske interakcije, π−interakcije i vodikove veze, te su pomoću njih objašnjeni odzivi kristala na vanjsku mehaničku silu.This diploma thesis presents synthesis of coordination polymers of cadmium(II) halides with 2-methylpyrazine (2-Mepz), 3-methylpyridine (3-Mepy) and 4-methylpyridine (4-Mepy). Nine complexes ([CdCl2(2-Mepz)]n (1), [CdBr2(2-Mepz)]n (2), [CdI2(2-Mepz)]n (3), [CdCl2(3- Mepy)2]n (4), [CdBr2(3-Mepy)2]n (5), [CdI2(3-Mepy)2] (6), [CdCl2(4-Mepy)2]n (7), [CdBr2(4- Mepy)2]n (8) and [CdI2(4-Mepy)2]n (9)) were synthesized using classical solution synthesis and their single crystals were grown by the solvent layering technique. The products were characterized by thermal methods (TGA, DSC), infrared spectroscopy (IR) and powder X-ray diffraction (PXRD). The molecular and crystal structure of grown single crystals were determined by single crystal X-ray diffraction analysis (SCXRD). Also, the response of needlelike crystals to external mechanical force was examined and, in the case of elastic flexibility, the elastic response was quantified. Supramolecular interactions, namely, π−interactions and hydrogen bonds, were determined in the crystal structure and were employed in rationalization of the crystals responses to external mechanical force

    Interactions of B-lymphocytes and bone cells in health and disease

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    Bone remodeling occurs through the interactions of three major cell lineages, osteoblasts, which mediate bone formation, osteocytes, which derive from osteoblasts, sense mechanical force and direct bone turnover, and osteoclasts, which mediate bone resorption. However, multiple additional cell types within the bone marrow, including macrophages, T lymphocytes and B lymphocytes influence the process. The bone marrow microenvironment, which is supported, in part, by bone cells, forms a nurturing network for B lymphopoiesis. In turn, developing B lymphocytes influence bone cells. Bone health during homeostasis depends on the normal interactions of bone cells with other lineages in the bone marrow. In disease state these interactions become pathologic and can cause abnormal function of bone cells and inadequate repair of bone after a fracture. This review summarizes what is known about the development of B lymphocytes and the interactions of B lymphocytes with bone cells in both health and disease

    Solvolytic behaviour of ferrocenylphenylmethyl butanoates in 60% aqueous acetone

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    Konstante brzine solvolize k izmjerene su različito supstituiranim fenilferocenilmetilnim butanoatima 60%-tnom vodenom acetonu. Konstruiran je graf ovisnosti log k o parametru elektrofugalnosti Ef te je dobivena odlična linearna ovisnost (R2 > 0,99) što opravdava korištenje LFER modela log k = sf ( Nf + Ef ) i potvrđuje izmjerene vrijednosti parametra Ef korištenih elektrofuga. Iz korelacijskog pravca izračunati su parametri nukleofugalnosti za butanoat u 60%-tnom vodenom acetonu koji iznose Nf = -4,54 i sf = 0,99. Dobiveni parametri uspoređeni su s vrijednostima parametara za butanoate u 80%-tnom vodenom acetonu koji upućuju na povećanje nukleofugalnosti povećanjem količine vode u otapalu zbog boljih solvatacijskih efekata za negativno nabijene izlazne skupine. Nukleofugalnost butanoata u 60%-tnom vodenom acetonu uspoređena je s drugim izlaznim skupinama (kloridna, benzoatna, acetatna) te je zaključeno da je butanoat vrlo slab nukleofug. Razmotren je utjecaj različitih susptituenata na fenilnom prstenu fenilferocenilmetilnih supstrata usporedbom Ef vrijednosti te korištenjem Hammet-Brownove jednadžbe. Niske apsolutne vrijednosti Hammet-Brownovog parametra ρ+ za različito supstituirane fenilferocenilmetil-butanoate upućuju na to da se u prijelaznom stanju reakcije solvolize razvija mala količina pozitivnog naboja i potvrđuju prevladavajući elektron-donirajući utjecaj ferocena na reakcijski centar koji zasjenjuje utjecaj supstituenata na fenilnom prstenu. Istaknuta je mogućnost primjene ljestvica elektrofugalnosti i nukleofugalnosti u predviđanju konstanti brzine solvolize različitih kombinacija elektrofuga i nukleofuga u danom otapalu te korištenje slabih izlaznih skupina kao što su butanoati u određivanju elektrofugalnosti jakih elektrofuga, primjerice različito supstituiranih fenilferocenilmetilnih kationa.Solvolysis rates k were measured for differently substituted ferrocenylphenylmethyl butanoates in 60% aqueous acetone. Graph depicting log k vs. parameter of electrofugality Ef was plotted and great linear correlation (R2>0,99) was obtained, which then justifies the use of LFER model log k = sf (Nf + Ef) and confirms measured Ef values of used electrofuges. Nucleofugality parameters were calculated using the correlation graph for butanoate in 60% aqueous acetone which amount to Nf = -4,54 and sf = 0,99. The obtained values were compared to the nucleofugality parameters of butanoates in 80% aqueous acetone which display that the increase of the amount of water in the solvent causes the nucleofugality parameters to increase due to better solvatation effects. Nucleofugality of butanoate in 60% aqueous acetone was compared to other leaving groups (chloride, benzoate, acetate) with the conclusion that butanoate is a very weak nucleofuge. The impact of different substituents on the phenyl ring of ferrocenylphenylmethyl substrates was reviewed by comparing Ef values and using Hammet-Brown equation. Low absolute values of Hammet-brown parameter ρ+ for differently substituted ferrocenylphenylmethyl butanoates indicate that the generation of the positive charge in the transition state of solvolysis reaction is considerably reduced which confirms the strong electron-donating ability of the ferrocenyl group overshadowing the phenyl substituents' impact. The possibility of applying the electrofugality and nucleofugality scales in the prediction of solvolysis rates for different electrofuge-nucleofuge combinations in given solvents as well as using weak leaving groups like butanoates in determining electrofugality of strong electrofuges, like differently substituted ferrocenylphenylmethyl cations, was pointed out

    Organocatalytic stereoselective synthesis of isoindolinone derivatives with triaryl substituted quaternary stereogenic center

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    U sklopu ove doktorske radnje razvijen je protokol koji opisuje sintezu derivata izoindolinona s triaril-supstituiranim kvaternim stereogenim centrom u organokatalitičkim uvjetima. Provedeno je stereoselektivno i regioselektivno ariliranje izoindolinona, te aza-Friedel Craftsova adicija pirola kroz položaj C3. Tako opisane transformacije katalizirane kiralnim fosfornim kiselinama uključuju širok raspon različitih nukleofila i izoindolinonskih alkohola za stvaranje kvaternog stereogenog centra s tri arilna supstituenta u odličnim prinosima i razinama enantioselektivnosti (do 98% prinosa, do 99,5:0,5 e.r.). Mehanizam stereokemijske indukcije predložen je na temelju rezultata dobivenih kvantno-mehaničkim računima i kontrolnim eksperimentima. Ispitana je primjenjivost opisanih metodologija provedbom reakcije na većoj skali i posttransformacijskom reakcijom bez gubitka optičke čistoće.An organocatalytic asymmetric protocol for the synthesis of isoindolione derivatives possessing triaryl-substituted quaternary stereogenic centers is developed. Stereoselective and regioselective arylation of isoindolinones with phenols and pyrroles at C3 position has been carried out. Described stereoselective transformations proceed smoothly with a broad range of arenes and isoindolinone alcohols in reactions mediated by chiral phosphoric acid catalyst to generate triaryl-substituted quaternary stereogenic centers in excellent yields and enantioselectivities (up to 98% yield, up to 99,5:0,5 e.r.). In the order to shed light on the mechanism of stereochemical induction, control experiments and density functional theory calculations have been performed. Applicability of such described methodologies has been investigated by conducting the postmodification and scale-up reaction without loss of optical purity in the products

    Determination of the main phase transition temperature of neutral lipids by UV/Vis spectroscopy

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    Lipidi u vodenom mediju tvore liposome, sferične strukture u kojima se slažu u dvosloje. Faza, odnosno način slaganja lipida u dvosloje, funkcija je temperature. Glavni fazni prijelaz je prijelaz lipida iz faze gela u fazu fluida i opaža se pri temperaturi mekšanja Tm. Uz razlikovnu pretražnu kalorimetriju kao rutinsku tehniku određivanja Tm odnedavno se ističe i UV/Vis spektroskopija. U sklopu ovog rada pripremljene su suspenzije 1,2-dipalmitoil-sn-glicero-3- fosfokolina (DPPC), 1,2-dipalmitoil-sn-glicero-3-fosfoetanolamina (DPPE), 2-oleil-1- palmitoil-glicero-3-fosfoetanolamina (POPE) i sfingomijelina (SM) u acetatnom, fosfatnom i karbonatnom puferu (pH = 4,09; 7,01; 9,19). Razlikovnom pretražnom kalorimetrijom i temperaturno-ovisnom UV/Vis spektroskopijom određene su vrijednosti Tm lipida te je ispitan utjecaj pH medija na Tm. Pokazano je da je temperaturno-ovisna UV/Vis spektroskopija prikladna za određivanje Tm te da promjena pH najviše utječe na DPPE i POPE liposome.Lipids form liposomes in which they arrange into bilayers. The transition of lipids from the gel to the fluid phase, namely the main phase transition, is observed at the melting temperature Tm. Alongside differential scanning calorimetry (DSC), a routine technique for Tm determination, UV/Vis spectroscopy recently stood out. As part of this thesis, suspensions of 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), 2-oleyl-1-palmitoyl-glycero-3-phosphoethanolamine (POPE) and sphingomyelin (SM) in three buffers (pH = 4.09; 7.01; 9.19) were prepared. Using DSC and temperaturedependent UV/Vis spectroscopy, Tm of lipids were determined and the influence of pH on Tm was examined. It was shown that temperature-dependent UV/Vis spectroscopy is suitable for determining Tm and that DPPE and POPE liposomes are affected by the change in the pH

    Possibilities of applying security controls in the field of information systems security

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    Porastom korištenja tehnologije u modernom svijetu, njezina implementacija u svim državnim sektorima se povećava. Kako u civilstvu, tako i u vojsci. Tehnologija se u većini slučajeva koristi kako bi se olakšalo čovjekova egzistencija, znajući to, slanje informacija postaje ključno te samim time zaštita istih postaje obaveza. Kontrola informacija te sami njen posjed postaje od presudne važnosti i informacija kao takva može utjecati na dosadašnji rad neke organizacije ili državnog tijela. Na koje načine možemo zaštiti sustav od neželjenog upada i manipuliranja informacija? Cilj završnoga rada je konstruktivno obrazložiti temeljne standarde zaštite informacijskih sustava, njezinih područja sigurnosti te dati pregled na sigurnosne kontrole i njihovu primjenu na sigurnosne sustave.With the increasing use of technology in the modern world, its implementation in all sectors of government is on the rise, both in civilian and military domains. Technology is predominantly used to facilitate human existence, and with that in mind, the transmission of information becomes crucial, making its protection an obligation. The control and possession of information become of paramount importance, as information itself can impact the existing operations of an organization or a governmental body. In what ways can we protect systems from unauthorized intrusion and information manipulation? The aim of this final paper is to constructively explain the fundamental standards of information system security, its areas of security, and provide an overview of security controls and their application to security system

    Kinetic characterisation of aldolase immobilized on magnetic nanoparticles

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    Cilj ovog rada bio je odrediti kinetiku kovalentno imobiliziranog enzima DERA u reakciji dvostruke aldolne adicije acetaldehida i kloroacetaldehida. Produkt navedene reakcije je laktol – ključni prekursor u sintezi bočnog lanca statina, lijeka za snižavanje koncentracije kolesterola u krvi. Kao nosioc za imobilizaciju, korištene su magnetske nanočestice, sintetizirane hidrotermalnom metodom, funkcionalizirane 3-aminopropiltrietoksisilanom te aktivirane 10 %-tnim anhidridom jantarne kiseline. Kinetika je za oba koraka reakcije opisana Michaelis-Menteničinom jednadžbom, a kinetički su parametri procijenjeni metodom nelinearne regresije programa MicroMath Scientist. Uz to, razvijen je matematički model procesa i validiran u kotlastom reaktoru.The aim of this work was to determine the kinetics of the covalently immobilized DERA enzyme in the double aldol addition reaction of acetaldehyde and chloroacetaldehyde. The product of the mentioned reaction is lactol – a key precursor in the synthesis of the side chain of statin, a drug used for lowering blood cholesterol level. Magnetic nanoparticles were used as a carrier and were synthesized by the hydrothermal method, functionalized with 3-aminopropyltriethoxysilane and activated with 10 % succinic anhydride. The kinetics for both reaction steps was described by the Michaelis-Menten equation, and the kinetic parameters were estimated using the nonlinear regression method of the MicroMath Scientist software. A mathematical model of the process was also developed and validated in a batch reactor

    Development and validation of a chromatographic method for the determination of N-nitrosamines

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    N-nitrozamini su organski kemijski spojevi koji se klasificiraju kao kancerogeni za ljudsko zdravlje. Pojavljuju se svuda oko nas u raznim prehrambenim i kozmetičkim proizvodima, no posljednjih godina je otkriveno kako se u značajnoj količini javljaju kao nusprodukti dezinfekcije vode za piće korištenjem procesa poput kloriranja i kloraminacije. Vrlo je važno postići njihovu jednostavnu i brzu detekciju u vodi kako bi se odredila njezina prikladnost za piće. Cilj ovog rada je razviti metodu tekućinske kromatografije visoke djelotvornosti koja koristi detektor s nizom dioda za određivanje N-nitrozamina te provesti validaciju kako bi se odredila njezina prikladnost za tu namjenu. Ispitivanja su provedena na osam N-nitrozamina: N-nitrozodi-n-propilamin (NDPA), N-nitrozopirolidin (NPYR), N-nitrozodietilamin (NDEA), N-nitrozomorfolin (NMOR), N-nitrozo-di-n-butilamin (NDBA), N-nitrozopiperidin (NPIP), N-nitrozodifenilamin (NDPhA) i N-nitrozodimetilamin (NDMA). Kako bi se izabrala najprikladnija pokretna faza, najprije su provedena izokratna eluiranja s acetonitrilom, etanolom i metanolom kao B fazom, dok je u sva tri slučaja MilliQ voda činila A fazu. Dobiveni su rezultati pokazali kako je kombinacija acetonitrila i MilliQ vode najbolji izbor pokretne faze za određivanje N-nitrozamina te su upravo oni korišteni u daljnjem istraživanju. Za razvoj metode ispitivano je više gradijenata te se u konačnici kao najbolji izbor pokazao gradijent čije vrijeme analize traje 20 minuta uz protok 0,5 mL min^-1. Razvijena HPLC-DAD metoda je potom validirana pri čemu su ispitane izvedbene karakteristike metode: selektivnost, linearnost, ponovljivost, međupreciznost, istinitost, granica detekcije, granica kvantifikacije te je definirano radno područje metode. Metoda se analizom uzoraka vodovodne vode pokazala selektivnom što omogućuje njezinu primjenu za određivanje N-nitrozamina u vodi. Postignuta je dobra linearnost (R^2 ≥ 0,995) te je također zadovoljen kriterij za ponovljivost i međupreciznost (RSD ≤ 10 %) za sve N-nitrozamine. Zadovoljavajuće iskorištenje postignuto je pri višim koncentracijama, dok za niže koncentracije nije zadovoljen kriterij prihvatljivosti za sve N-nitrozamine. Rezultati su pokazali kako je razvijenom HPLC-DAD metodom moguće uspješno odrediti osam ispitivanih N-nitrozamina te provesti njihovu kvantifikaciju. Provedenom validacijom metode potvrđena je njezina primjenjivost u svrhu određivanja N-nitrozamina što omogućuje primjenu ove metode za analizu uzoraka vode.N-nitrosamines are organic chemical compounds which are classified as cancerogenic for humans. They appear all around us, such as food and cosmetic products but in recent years it was discovered that they appear in significant amounts as byproducts of water disinfection, such as chlorination and chloramination. It's important to achieve their simple and fast detection in water, in order to confirm water suitability for drinking. Aim of this research is to develop a high-performance liquid chromatography method with diode array detection for the determination of N-nitrosamines and to perform method validation to determine its fitness for purpose. Research has been carried out on eight N-nitrosamines: N-nitrosodipropylamine (NDPA), N-nitrosopyrrolidine (NPYR), N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMOR), N-nitrosodibutylamine (NDBA), N-nitrosopiperidine (NPIP), N-nitrosodiphenylamine (NDPhA) and N-nitrosodimethylamine (NDMA). To determine the best choice of the mobile phase, isocratic elution was performed with acetonitrile, ethanol, and methanol as B phase, while A phase was MilliQ water for all three cases. Obtained results have shown that combination of acetonitrile and MilliQ water was the best choice of mobile phase for N-nitrosamines determination, and they were used in further research. More than few gradients were tested and ultimately as the best choice was proved gradient whose analysis time lasts 20 minutes with flow rate of 0,5 mL min^-1. Developed HPLC-DAD method was then validated whereby the following performance characteristics were tested: selectivity, linearity, repeatability, intermediate precision, trueness, detection limit, quantification limit, and the working range. The method was proved to be selective by analyzing tap water samples, which enables its application for the determination of N-nitrosamine in water. The method achieved good linearity (R^2 ≥ 0.995) and also met the criteria for repeatability and intermediate precision (RSD ≤ 10%) for all N-nitrosamines. Satisfactory recovery was achieved at higher concentrations, while the acceptance criteria for all N-nitrosamines was not achieved at lower concentration level. Validation results confirmed applicability of the developed HPLC-DAD method for quantitative determine of all eight tested N-nitrosamines in water samples

    Adsorption of poly(N-ethyl-4-vinylpyridine) on titanium dioxide colloidal film and particles

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    U sklopu ovog diplomskog rada ispitan je utjecaj adsorpcije jakog polikationa poli(N-etil-4-vinilpiridina) (P4VP) na titanijev dioksid u obliku nanočestica te koloidnog filma. Određena su površinska svojstva titanijeva dioksida. Elektroforetskim raspršenjem svjetlosti određena je izoelektrična točka titanijeva dioksida, a potenciometrijskom kiselinsko-baznom titracijom točka nul-naboja. Metodom izotermalne titracijske kalorimetrije kvalitativno je okarakteriziran proces protonacije površinskih skupina titanijeva dioksida. Za određivanje površinskog potencijala titanijeva dioksida izrađene su elektrode s pločicama titanija presvučenim oksidnim slojem. Površina istih pločica okarakterizirana je mikroskopijom atomskih sila i optičkim mikroskopom. Adsorpcija polikationa P4VP-a praćena je metodom UV-Vis spektrofotometrije te je ispitana valjanost adsorpcijskih izotermi. Elektroforetskim i dinamičkim raspršenjem svjetlosti određeni su elektrokinetički potencijal i hidrodinamički promjer čestica titanijeva dioksida s adsorbiranim P4VP-om. Ispitan je utjecaj adsorbiranog P4VP-a na površinski potencijal titanijeva dioksida te na topologiju titanijeva dioksida.As part of this thesis, the influence of adsorption of strong poly(N-ethyl-4-vinylpyridine) (P4VP) on titanium dioxide in the form of nanoparticles and colloidal film was examined. Surface properties of titanium dioxide were determined. The isoelectric point of titanium dioxide was determined by electrophoretic light scattering and the point of zero charge by potentiometric acid- base titration. The process of protonation of titanium dioxide surface groups was qualitatively characterized by isothermal titration calorimetry. To determine the surface potential of titanium dioxide, electrodes with titanium plates coated with an oxide layer were made. The surface of the same plates was characterized by atomic force microscopy and optical microscopy. The adsorption of the polycation P4VP was monitored by UV-Vis spectrophotometry and the validity of the adsorption isotherms was tested. The electrokinetic potential and hydrodynamic diameter of titanium dioxide particles with adsorbed P4VP were determined by electrophoretic and dynamic light scattering. The influence of adsorbed P4VP on the surface potential of titanium dioxide and on the topology of titanium dioxide was examined

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