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Synthesis of metal-organic frameworks
No full textMetalo-organske mreže (MOF) su posebni materijali koji su savršena poveznica anorganske i organske kemije. Građeni su od centralnog atoma koji je anorganski metal, te organskog liganda. MO mreže tvore novu vrstu poroznih materijala jer se razlikuju zbog svoje velike površine i pora, male gustoće, te velike stabilnosti i funkcionalnosti. Velika primjena metaloorganskih mreža je u petrokemijskoj industriji, biomedicini, katalizama, itd. Sinteza novih metalo-organskih mreža uvelike pospješuje očuvanju ekologije i okoliša budući da se u ovisnosti o veličini pora koriste za skladištenje štetnih plinova i zagađivača u okolišu. Cilj ovog rada bio je sintetizirati metalo-organsku mrežu koristeći heksametilentetraamin kao templat pri sobnoj temperaturi. Korišteni su različiti metali poput Co, Mn i Cr s propanskom kiselinom kao ligandom.Metal-organic framework is a special family of compounds which represents the perfect link between inorganic and organic chemistry. They are made up of a central metal cation and an organic ligand. MO frameworks form a new type of porous material because they have a large surface area and large pores, low density, high stability and functionality. Great applications of metal-organic frameworks are found in petrochemical industry, biomedicine, catalysis, etc. The synthesis of novel metal-organic frameworks greatly contributes to ecology and the preservation of the environment because depending on a pore size, various harmful gases and pollutants can be stored within the pores. In this research, the aim was to synthesize metal-organic frameworks using hexamethylenetetraamine as a template at room temperature. Various metals as Mn, Co and Cr were used in combination with propionic acid as the ligand
Synthesis and characterization of N,o- donor macrocyclic Schiff base complexes
No full textPredmet istraživanja ovog diplomskog rada je sinteza i karakterizacija kompleksnih spojeva s N,O - donornim makrocikličkim Schiffovim bazama. Pripremljene su 4 makrocikličke Schiffove baze (L1, L2, L3, L4) koje su služile kao ligandi tj. kao N,O - donori, kao metalni kationi prijelaznih elemenata koristili su se srebrov nitrat i srebrov perklorat . Priprava kompleksnih spojeva izvedena je uz odgovarajući ligand i metalni kation na temperaturi refluksa uz diklormetan i metanol kao otapalo. Od izvedenih sinteza metodom difuzije uspješno su izolirana i identificirana 3 spoja (, i . Dobiveni spojevi su karakterizirani IR spektroskopijom (FTIR) koja ukazuju na koordinaciju imino skupine sa atomom srebra. Molekulske i kristalne strukture određene su rendgenskom difrakcijom.The subject of this diploma thesis is the synthesis and characterization of N,O - donor macrocyclic Schiff base complexes. 4 macrocyclic Schiff bases (L1, L2, L3, L4) were prepared and used as ligands, ( N,O - donors), silver nitrate and silver perchlorate were used as a metal cations of transition elements. The preparation of complex compounds was performed with the appropriate ligand and metal cation at reflux temperature with dichloromethan and methanol as solvent. From performed syntheses by diffusion method, 3 compounds were successfully isolated and identified (, and . The synthesis compounds were characterized by IR spectroscopy (FTIR) and results indicate coordination of the imino group with the silver atom. Molecular and crystal structure were determined by single-crystal X-ray diffraction
Monitoring of selected water quality parameters of River Drava surface water
No full textStalni porast svjetske populacije zahtijeva sve učinkovitiju proizvodnju hrane i brzu urbanizaciju, zbog čega se na svjetskoj razini može uočiti sve veći utrošak gnojiva. Primjena gnojiva znatno povećava urod, ali znatno povećava i zagađenje prirodnih voda. U radu je prikazana procijena kvalitete površinske vode rijeke Drave u Republici Hrvatskoj, koja se temelji na fizikalno-kemijskim parametrima i aktualnim propisima i regulativama. Uzorci su prikupljani mjesečno u razdobljuod 14 godina (2004. - 2017.), a analizirani parametri su između ostalih bili pH, kemijska potrošnja kisika (KPK-Mn), biokemijska potrošnja kisika , dušikovi spojevi (nitrati, nitriti i ukupni dušik) i spojevi fosfora (ortofosfati i ukupni fosfor). Dobiveni rezultati upućuju na kvalitetu vode koja se može opisati dobrom do vrlo dobrom, ovisno o parametru i godini. Neovisno o tome, kontinuirani monitoring je potrebno nastaviti, kako bi se pratilo stanje površinske vode i primjena mjera zaštite voda od daljnjeg zagađenja. Također, u radu je opisan i metodički dio za nastavnu jedinicu "Voda" za 7. razred Osnovne škole. Metodički dio sadrži pisanu pripremu za nastavni sat, prilog 1, pokus, radni listić te listić za domaću zadaću. Predviđeno je frontalno predavanje, grupni rad te zajedničko ponavljanje naučenog gradiva kroz pitanja na radnom listiću.Ever-increasing world population requires efficient food production and extensive urbanization. Hence, annual increase in implementation of nitrogen fertilizers which increases agricultural yield, but also increases water pollution. This thesis gives an overview and an assessment of water quality of Drava River, based on the analysis of water physico-chemical parameters according to the national laws and regulations. Water samples were collected monthly over a period of 13 years (2004 - 2017). Analysed parameters were, among others, pH, chemical oxygen demand (COD-Mn), five-day biochemical oxygen demand ), nitrogen (nitrates, nitrites, total nitrogen) and phosphorus compounds (orthophosphates, total phosphorus). The obtained results indicate a water quality status between good and very good, depending on the parameter and year. Regardless, continuous monitoring of water quality is necessary in order to ensure adequate implementation of measures for water quality protection. Also, the thesis contains a methodical part regarding class unit "Water" for the 7th grade of elementary school. The methodical part contains written preparation for the class, supplement 1, experimental part, worksheet and homework sheet. The frontal type of class is planned, pupil group work and ending with joint review of the lesson with the help of the worksheet
Covalent functionalization of carbon nanotubes
No full textUgljične nanocjevčice (CNT) su alotropska modifikacija ugljika koje imaju oblik cilindričnih ugljikovih molekula. Njihova svojstva ih čine potencijalno korisnima u različitim područjima kao npr. u nanotehnologiji, elektronici, optici i drugim područjima znanosti o materijalima. One pokazuju izvanrednu snagu i jedinstvena električna svojstva te su učinkoviti vodiči topline. U ovome radu opisana je kvaternizacija NH2 funkcionaliziranih višestjenčanih ugljikovih nanocijevi (MWCNT) u svrhu dobivanja spoja koji će se koristiti u membrani elektrode za detekciju anionskih tenzida. Za pripravu ciljnog produkta predložen je sintetski put koji je podrazumijevao nitriranje MWCNT te redukciju nitro skupina u amino s ciljem priprave NH2 funkcionaliziranih MWCNT.Posljednji korak predloženog sintetskog puta je uključivao kvaternizaciju pripravljenih NH2 funkcionaliziranih MWCNT s metil jodidom. Nakon provedene reakcije nitriranja MWCNT, IR spektroskopijom je ustanovljeno kako nije došlo do funkcionalizacije MWCNT nitro skupinama. Prema tome daljnji koraci u predloženom sintetskom putu nisu provedeni a za pripravu ciljnog produkta korištene su komercijalno dostupne NH2 funkcionalizirane MWCNT. Strukture svih pripravljenih produkata pretpostavljene su IR spektroskopijom.Covalent nanotubes (CNT) are an allotropic carbon modification, and are shaped as cylindrical carbon molecules.They have properties which can potentially be useful in a large spectrum as nanotechnology, electronics, optics and other fields of material science. They show a great amount of strength, unique electrical and thermal properties. This paper describes quaternization of NH2 functionalized multi walled carbon nanotubes (MWCNT)with the aim of preparationa compound which can be used in the membrane of the electrode for the detection of anionic surfactants. For the preparation of target compound synthetic pathway has been proposed which included nitration of MWCNT and reduction of nitro to amino group with the purpose of preparation NH2 functionalized MWCNT. Last step of proposed synthetic route included quaternization of prepared NH2 functionalized MWCNT with methyl iodide. Since nitration of MWCNT was not successful, which was assumed with IR spectroscopy, for the quaternization of NH2 functionalized MWCNT commercially available NH2 functionalized MWCNT were used. The structures of all prepared compounds were assumed with IR spectroscopy
Amination of naphthalic anhydride derivative
No full textU ovom završnom radu opisana je sinteza indikatora u svrhu određivanja koncentracije selenija. Za pripravu ciljnog produkta predložen je sintetski put koji podrazumijeva četiri sintetska koraka. U prvom koraku predloženog sintetskog puta reakcijom elektrofilne aromatske supstitucije dolazi do nitriranja polaznog spoja, 4-brom-1,8-naftalanhidrida, pri čemu nastaje spoj 1 koji u svojoj strukturi sadrži nitro skupinu. Drugi korak podrazumijeva reakciju nukleofilne aromatske supstitucije u kojoj dolazi do supstitucije atoma broma azidnom skupinom pri čemu nastaje spoj 2. Sljedeći korak pretpostavljenog sintetskog puta obuhvaća prevođenje anhidrida, spoja 2, u imid reakcijom s propilaminom pri čemu nastaje spoj 3. Posljednji korak predloženog sintetskog puta podrazumijeva redukciju spoja 3 s hidrazin hidratom i Ra-Ni kao katalizatorom što bi rezultiralo sintezom ciljnog produkta, spoja 4. Budući da sinteza spoja 3 nije bila uspješna, posljednji korak predloženog sintetskog puta koji podrazumijeva redukciju azido i nitro skupine, nije proveden, a ciljni produkt 4 nije sintetiziran. Strukture spojeva 1 i 2 su pretpostavljene IR, i NMR spektroskopijom.In this work, the synthesis of indicator, for determination of selenium concentration, is described. A synthetic pathway, which contains four synthetic steps, has been proposed. In the first step of the proposed synthetic pathway, electrophilic aromatic substitution of starting compound, 4-bromo-1,8-naphthalic anhydride, was carried out. As the result of this reaction compound 2, which contains nitro group in the structure, was synthesized. The second step was nucleophilic aromatic substitution of bromine atom with an azide group which yielded compound 2. Next step of the proposed synthetic route is conversion of anhydride (2) to imide with propylamine in order to form compound 3. The last step involves reduction of compound 3 with hydrazine hydrate and Ra-Ni as catalyst for the purpose of synthesis target compound 4. Since synthesis of compound 3 was not successful, last step of proposed synthetic pathway was not carried out and target compound 4 was not synthesized. Structures of compounds 1 and 2 were assumed with IR, and NMR spectroscopy
Physiological condition of dandelion (Taraxacum officinale Weber) in rural areas assessed by biochemical parameters
No full textMaslačak (Taraxacum officinale Weber) je samonikla biljna vrsta sjeverne polutke. Zbog visoke sposobnosti akumulacije kemijskih elemenata, ispunjava sve uvjete za ispitivanje utjecaja zagađenja te se smatra dobrim bioindikatorom. U ovom radu opisano je istraživanje utjecaja poljoprivrednog zagađenja na biokemijske parametre maslačka što uključuje koncentraciju proteina, klorofila i karotenoida, sadržaj askorbinske kiseline i ukupnih topivih polifenola. Povećana koncentracija proteina u uzorcima prikupljenim na zagađenim lokacijama bila je popraćena smanjenjem ukupnih topivih polifenola i askorbinske kiseline te koncentracije karotenoida i klorofila. Nadalje, došlo je do povećanja ukupne antioksidativne aktivnosti kod uzoraka prikupljenih na zagađenim lokacijama. Metode analize glavnih komponenata i infracrvene spektroskopije Fourierovim transformacijama (FTIR) potvrdile su razlike rezultata dobivenih biokemijskim analizama. To ukazuje da su poljoprivredni zagađivači negativno utjecali na produkciju sekundarnih metabolita unatoč dobrom fiziološkom odgovoru te je maslačak pogodna biljna vrsta za ispitivanje utjecaja poljoprivrednog zagađenja i abiotičkog stresa.Dandelion (Taraxacum officinale Weber) is a wild plant species of the northern hemisphere. Due to its high ability to accumulate chemical elements, it is a good species for the investigation of the impact of pollution and is considered a good bioindicator. This paper describes the impact of agricultural pollution on the biochemical parameters of dandelion, which include the concentration of proteins, chlorophyll and carotenoids, the content of ascorbic acid and total soluble polyphenolics. The increased protein concentration in samples collected at contaminated areas was accompanied by a decrease in total soluble polyphenolics, ascorbic acid, carotenoid and chlorophyll concentrations. Furthermore, there was a significant increase in total antioxidant activity in samples collected at contaminated sites. The principal component analysis and Fourier transform infrared spectroscopy (FT-IR) confirmed the differences in the results obtained by biochemical analyses. This indicates that agricultural pollutants have negatively affected the production of secondary metabolites despite the good physiological condition of the plants and that a dandelion is a suitable plant species for investigation of the impact of agricultural pollution and abiotic stress
In situ istraživanje termičkog raspada epitaksijalnih slojeva GeSn legure transmisijskom elektronskom mikroskopijom
No full textLegura s x> 0,01 termodinamički je metastabilna i Sn na temperaturama iznad ≈230°C teži odvajanju, difundiranju i taloženju kao β-Sn u strukturama nalik kapljicama. In situ eksperimenti žarenja u transmisijskom elektronskom mikroskopu omogućuju promatranje i proučavanje termičkog raspada epitaksijalnih slojeva . Jedan od glavnih zahtjeva za ispitivanja putem TEM-a je uzorak proziran za elektrone. Prema tome priprema uzorka je ključni korak prema TEM pokusima. Postupak pripreme uzorka razvijen je kombinacijom različitih tehnika pripreme. Prvo, MBE sintetizirani i referentni materijal Si (s Ge kvantnim točkama) pripremljeni su tehnikom klinastog poliranja. Nadalje, fokusirani ionski snop (FIB) korištena je za pripremu grijaćeg čipa za in situ eksperiment žarenja. Različite metode mikroskopije korištene su za optimizaciju i validaciju razvijenog postupka pripreme uzorka za in situ TEM eksperiment žarenjaThe alloy with x>0.01 is thermodynamically metastable and Sn tends to diffuse, segregate or precipitate as β-Sn in a droplet-like structure at temperature above ≈230°C. In situ heating experiments via transmission electron microscopy (TEM) allows us to observe and study the decomposition process of . The main requirement for TEM investigation is an electron transparent specimen. Hence, specimen preparation is a key step towards TEM experiments. The sample preparation procedure has been developed using a combination of preparation techniques. The MBE synthesized and reference material Si (with Ge quantum dots) have been prepared with wedge polishing technique. Further, focused ion beam (FIB) has been used to prepare a heating chip for the in situ TEM heating experiment. Various microscopy methods have been used to optimize and validate the developed sample preparation procedure
Crystal structure solution and refinement of N,O - donor macrocyclic compounds
No full textMakrociklički spojevi i njihova svojstva jedno su od popularnijih tema kemijskih istraživanja današnjice. Zbog svoje jedinstvene strukture, koriste se za vezanje specifičnih molekula ili metala te kompleksiranje istih. Predmet ovog rada je rješavanje i utočnjavanje kristalnih struktura 6 -donornih makrocikličkih spojeva. Spojevi kojima je rješavana struktura su mD1 (1,5-diaza-2,4:7,8:16,17-tribenzo-9,15-dioksa-ciklooktadeka-1,5-dien), mD2 (1,5-diaza-2,4:7,8:15,16-tribenzo-9,14-dioksa-cikloheptadeka-1,5-dien), mD3 (1,5-diaza-2,4:7,8:17,18-tribenzo-9,16-dioksa-ciklononadeka-1,5-dien), mD4 (1,5-diaza-2,4:7,8:18,19-tribenzo-9,17-dioksa-cikloikosa-1,5-dien), mD1R (reducirana forma mD1 spoja) i mD4R (reducirana forma mD4 spoja). Za utočnjavanje i rješavanje kristalnih struktura korišteni su programi i Mercury. Spojevima je određena struktura i kristalografski parametri. Sve dobivene strukture su tetradentatni makrociklički ligandi koji sadrže dva atoma kisika i dušika na donornim mjestima. Kako bi mogli razlikovati njihova svojstva, ispitani su strukturni parametri - duljine veza, torzijski kutovi, amplitude nabiranja i veličine šupljina središnjih prstenova. Na temelju ispitanih parametara određena su svojstva svakog spoja poput planarnosti, stabilnosti, jačini vezanja i kompleksiranja pojedinih vrsta.Macrocyclic compounds and their properties are one of the more popular topics of chemical research of today. Due to their unique structure, they are used to bind and complex with specific molecules or metals. The subject of this thesis is the solution and refinement of crystal structures of six specific - donor macrocyclic compounds. The observed compounds are mD1 (1,5-diaza-2,4: 7,8: 16,17-tribenzo-9,15-dioxa-cyclooctadeca-1,5-diene), mD2 (1,5-diaza-2, 4: 7,8: 15,16-tribenzo-9,14-dioxa-cycloheptadeca-1,5-diene), mD3 (1,5-diaza-2,4: 7,8: 17,18-tribenzo-9) , 16-dioxa-cyclononadeca-1,5-diene), mD4 (1,5-diaza-2,4: 7,8: 18,19-tribenzo-9,17-dioxa-cycloeicosa-1,5-diene) , mD1R (reduced form of the mD1 compound) and mD4R (reduced form of the mD4 compound). For solving and refinement of crystal structures programs and Mercury were used. The structure and crystallographic parameters of the compounds were determined. All achieved structures were tetradentate macrocyclic ligands containing two oxygen and nitrogen atoms at the donor sites. In order to be able to distinguish their properties, structural parameters were examined - bond lengths, torsion angles, puckering amplitudes and hole sizes of central rings. Based on examined parameters, the properties of each compound such as planarity, stability, bond strength and specific complexation ability were determined
Determination of cholesterol in eggs enriched with functional ingredients
No full textOdređivana je koncentracija kolesterola u jajima nesilica koje su konzumirale krmnu smjesu obogaćenu funkcionalnim sastojcima te u jajima nesilica koje su konzumirale krmnu smjesu koja nije obogaćena i jajima proizvedenim na obiteljskom poljoprivrednom gospodarstvu. Uz ostale funkcionalne sastojke, u krmnu smjesu za nesilice dodavano je riblje ulje koje ima povoljan utjecaj na povećanje razine omega-3 masnih kiselina. U odnosu na ukupan sadržaj ulja, dodano je 0,3; 0,9; i 1,5% ribljeg ulja. Pripremljeni uzorci žumanjaka jaja analizirani su tekućinskom kromatografijom visoke razlučivosti s UV detekcijom. Najveća koncentracija kolesterola, u odnosu na literaturne podatke, određena je u domaćim jajima a nešto niža u jajima nesilica koje su konzumirale krmnu smjesu koja nije obogaćena funkcionalnim sastojcima. U jajima nesilica koje su konzumirale krmu smjesu obogaćenu funkcionalnim sastojcima, najniža koncentracija kolesterola nađena je kod jaja nesilica koje su konzumirale smjesu s 0,3% ribljeg ulja a najviša koncentracija u jajima nesilica koje su konzumirale smjesu s 1,5% ribljeg ulja. Usporedbom dobivenih rezultata može se vidjeti da je u jajima nesilica koje su konzumirale krmnu smjesu s dodatkom ribljeg ulja koncentracija kolesterola nešto niža u odnosu na jaja nesilica koje su konzumirale smjesu koja nije obogaćena, ali ne značajno. Jaja proizvedena na obiteljskom poljoprivrednom gospodarstvu imaju najvišu razinu kolesterola.The concentration of cholesterol in laying hens eggs that consumed feed mixture enriched with functional ingredients, laying hens eggs that consumed feed mixture that was not enriched and eggs produced on the family farm was determined. In addition to other functional ingredients, fish oil has been added to the feed mixture for laying hens, which has a beneficial effect on increasing the level of omega-3 fatty acids. In relation to the total oil content 0.3, 0.9 and 1.5% fish oil was added. Prepared egg yolk samples were analyzed by high performance liquid chromatography with UV detection. The highest concentration of cholesterol, in relation to the literature data, was determined in eggs produced on family farm and lower concentration in the eggs of laying hens that consumed feed mixture that was not enriched with functional ingredients. In laying hens that consumed feed mixture enriched with functional ingredients, the lowest concentration of cholesterol was found in laying hens eggs that consumed mixture with 0.3% fish oil and the highest concentration in laying hens that consumed mixture with 1.5% fish oil. Comparing the obtained results, it can be seen that in the eggs of laying hens that consumed feed mixture with the addition of fish oil, the cholesterol concentration is slightly lower compared to the eggs of laying hens that consumed mixture that was not enriched but not significantly. Eggs produced on a family farm have the highest cholesterol level
Determination of vitamin E in eggs enriched with functional ingredients
No full textVitamin E je vitamin topiv u mastima i izvrstan je biološki antioksidans. Izuzetno je važan za čovjekovo zdravlje te je ključan dodatak hrani za životinje zbog jačanja imunološkog statusa, poboljšanja kvalitete hrane i na taj način povećavanja unosa vitamina E u organizam čovjeka. Cilj ovog istraživanja bio je tekućinskom kromatografijom visoke razlučivosti odrediti sadržaj vitamina E u jajima dobivenim od nesilica koje su hranjene krmnim smjesama obogaćenim funkcionalnim sastojcima. Određivana je koncentracija vitamina E u jajima dobivenim od nesilica hranjenih standardnom krmnom smjesom, u jajima dobivenim od nesilica hranjenih smjesom s dodatkom vitamina E, komercijalno dostupnim jajima te jajima dobivenim od nesilica s obiteljskih poljoprivrednih gospodarstava. Analizirani su pripremljeni uzorci žumanjaka i izmjerene su vrijednosti koncentracija vitamina E. Najveća koncentracija vitamina E, u odnosu na literaturne podatke, izmjerena je u skupini jaja nesilica čija je prehrana bila obogaćena vitaminom E. Nešto niža koncentracija izmjerena je u jajima nesilica s obiteljskih poljoprivrednih gospodarstava koje su hranjene raznolikom hranom. Prosječna vrijednost vitamina E u jajima nesilica hranjenih standardnom krmnom smjesom iznosila je 34 % manje u odnosu na literaturne podatke. Najniža koncentracija izmjerena je u komercijalno dostupnim jajima. Prosječna vrijednost je bila znatno manja u odnosu na literaturne podatke i na podatke izmjerenih vrijednosti ostalih skupina. Usporedbom podataka vidljivo je da će dodatak vitamina E u hranu nesilica povećati njegov sadržaj u jajima. Također je vidljivo da sadržaj vitamina E u jajima ovisi o hrani kojom su nesilice hranjene.Vitamin E is a fat-soluble vitamin and is an excellent biological antioxidant. It is extremely important for human health and is a key additive to animal feed due to the strengthening the immune status, improving food quality and thus increasing the intake of vitamin E in the human body. The aim of this study was to determine the content of vitamin E in eggs obtained from laying hens fed with feed mixtures enriched with functional ingredients using high-resolution liquid chromatography. The concentration of vitamin E was determined in eggs obtained from laying hens fed with a standard feed mixture, in eggs obtained from laying hens fed with feed mixture enriched with vitamin E, commercially available eggs and eggs obtained from laying hens from family farms. The prepared yolk samples were analyzed and the values of vitamin E concentrations were measured. The highest concentration of vitamin E, compared to the literature data, was measured in the group of laying eggs whose diet was enriched with vitamin E. Slightly lower concentration was measured in eggs obtained from family farms where hens are fed with variety of foods. The average value of vitamin E in laying hens fed with standard feed mixture was 34% lower compared to literature data. The lowest concentration was measured in commercially available eggs. The average value was significantly lower in relation to the data found in literature and to the data of measured values of other groups. A comparison of the obtained data showed that the addition of vitamin E to the feed of laying hens will increase its content in eggs. It is also evident that the content of vitamin E in eggs depends on the food on which the laying hens are fed