1. Green mechanochemical synthesis of binary and ternary cadmium chalcogenides with tunable band gapsMatjaž Kristl, Neža Zanjkovič, Jona Kunej, Sašo Gyergyek, Janja Stergar, 2025, original scientific article Abstract: In this work, we report on the mechanochemical preparation and characterization of binary (CdS, CdSe, and CdTe) and ternary (CdS0.5Se0.5, CdS0.5Te0.5, and CdSe0.5Te0.5) cadmium chalcogenides. The compounds were synthesized in a planetary micro mill using a zirconia grinding bowl and zirconia grinding balls. The products were examined by powder X-ray diffraction (pXRD), transmission electron microscopy (TEM), energydispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), UV–Vis spectroscopy, and differential scanning calorimetry (DSC). Interestingly, CdO formed as a by-product only during milling of Cd+S and Cd+Se in air, while it was absent in the Cd+Te and all ternary systems. The materials were obtained in the form of irregularly shaped aggregates measuring up to several hundred nanometers, composed of nearly spherical primary nanoparticles with diameters in the 10–20 nm range. The band gap energies calculated using Tauc plots for CdS0.5Se0.5, CdS0.5Te0.5, and CdSe0.5Te0.5 were 2.01 eV, 1.72 eV, and 1.53 eV, respectively. These results demonstrate the expected tunability of band gaps in ternary cadmium chalcogenides and attest to the potential of such materials for semiconducting applications, particularly in solar cells. The mechanochemical approach is once again shown to be a simple and effective method for the preparation of both binary and ternary chalcogenides, avoiding the use of solvents, toxic precursors, and energy-consuming reaction conditions.
Keywords: cadmium, sulfide, selenide, telluride, ternary compounds, mechanochemistry, band gap
Published in DKUM: 01.12.2025; Views: 0; Downloads: 1
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2. Sinteze in karakterizacija koordinacijskih spojin bakra s fluoropiridinskimi ligandi pod visokotemperaturnimi/hidrotermalnimi pogojiAna Koleša, 2025, undergraduate thesis Abstract: V diplomskem delu opisujemo sintezo in karakterizacijo novih koordinacijskih spojin bakra s fluoropiridinskimi ligandi. Opisujemo tudi sintezo in karakterizacijo nekaterih že poznanih struktur, ki nam jih je uspelo sintetizirati. Sintetizirali smo tri nove koordinacijske spojine: [Cu(4-Fpy)2(NO3)2], [Cu(μ-Ac)4(3-Fpy)2] in [Cu(FBPy)2(NO3)2]. Poleg teh nam je uspelo sintetizirati tri že znane koordinacijske spojine, kot so: tetrakis(μ2-Acetato)-bis(aqua-baker(II)), tetrakis(μ2‑Acetato)‑bis(acetonitril-baker(II)) in tetrakis(μ2‑Acetato)‑bis(metanol-baker(II)).
Prvo spojino, [Cu(μ-Ac)4(3-Fpy)2], smo sintetizirali iz bakrovega(II) acetata monohidrata raztopljenega v etanolu in 3-fluoropiridina. Drugo spojino, [Cu(4-Fpy)2(NO3)2], smo sintetizirali iz bakrovega(II) nitrata trihidrata raztopljenega v etanolu in 3-fluoropiridina. Za ligand tretje nove spojine, [Cu(FBPy)2(NO3)2], smo uporabili 4-bromo-2-fluoropiridin in sol bakrov(II) nitrat trihidrat raztopljeno v acetonitrilu.
Sinteze smo izvajali z mešanjem pri sobni temperaturi in s pomočjo refluksa, pri temperaturi vrelišča uporabljenega topila in z uporabo hidrotermalnega reakorja.
Molekulske strukture smo določili z rentgensko monokristalno analizo in uporabo termogravimetrične analize (TGA).
Keywords: koordinacijske spojine, baker, fluoropiridin
Published in DKUM: 12.09.2025; Views: 0; Downloads: 21
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3. Mixed-ligand copper(ii) complexes derived from pyridinecarbonitrile precursors : structural features and thermal behaviorAmalija Golobič, Matjaž Kristl, Tinkara Marija Podnar, Zvonko Jagličić, Brina Dojer, 2025, original scientific article Abstract: Pyridinecarbonitriles (pyCN), also referred to as cyanopyridines, are promising ligands for the formation of pyridine-based coordination compounds due to their two different N-donor atoms, which enable versatile coordination modes. Copper(II) complexes containing pyCN derivatives are of particular interest for their potential applications in medicinal chemistry and materials science. In this study, the synthesis, structural characterization, and thermal and magnetic properties of three new copper(II) complexes with 3-pyCN, 4-pyCN, and ethyl picolinimidate, obtained in situ by means of alcoholysis of 2-pyCN, are reported: [Cu2(μ-Ac)4(3-pyCN)2] (1), [Cu(H2O)2(Etpic)2]NO3 (2), and [Cu(NO3)2(CH3CN)(4-pyCN)2]·CH3CN (3). Single-crystal X-ray diffraction confirmed that complex 1 features a dinuclear paddle-wheel structure with bridging acetato ligands and monodentate 3-pyCN molecules, coordinated through the ring nitrogen, while complexes 2 and 3 are mononuclear. Thermal analysis showed an intense and highly exothermic decomposition of complex 3, containing nitrate ligands. Magnetic measurements revealed strong antiferromagnetic coupling in the dinuclear complex 1, whereas complexes 2 and 3 displayed paramagnetic behavior with effective magnetic moments ranging from 1.8 μB to 2.0 μB, consistent with isolated Cu(II) centers.
Keywords: copper(II) coordination compounds, cyanopyridines, crystal structure, magnetic properties, thermogravimetric analysis
Published in DKUM: 29.08.2025; Views: 0; Downloads: 5
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4. Sinteza in karakterizacija kobaltovih koordinacijskih spojin z izbranimi cianopiridinskimi ligandiAljaž Čelofiga, 2025, master's thesis Abstract: Smoter magistrskega dela je bil sinteza novih koordinacijskih spojin kobalta z različnimi vezanimi cianopiridini. Za izvedbo sinteze je bil kot vir kobaltovih ionov uporabljen kobaltov(II) acetat tetrahidrat z molekulsko formulo: Co(CH3COO)2 ∙ 4H2O ter trije različni cianopiridini (2-cianopiridin, 3-cianopiridin in 4-cianopiridin) z molekulsko formulo C6H4N2. Skupno je bilo izvedenih 24 sintez, ki so bile opravljene po dveh različnih metodah, in sicer: mešanje pri sobni temperaturi ter sinteza z mešanjem pod refluksom. Sintezirani produkti so bili karakterizirani s pomočjo Fourierjeve transformirajoče infrardeče spektroskopije ter z rentgensko analizo na monokristalu. Podatke o lastnostih in strukturi spojin smo pridobili s pomočjo termogravimetrične analize.Sintetizirana je bila nova kobaltova koordinacijska spojina z vezanim ligandom 4-cianopiridinom in molekulsko formulo: [Co(C2H3O2)2(C6H4N2)(H2O)3].
Keywords: kobaltove koordinacijske spojine, cianopiridini, Fourierjeva transformirajoča infrardeča spektroskopija, rentgenska monokristalna analiza, termogravimetrična analiza
Published in DKUM: 04.07.2025; Views: 0; Downloads: 37
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5. Sinteze in karakterizacija koordinacijskih spojin bakra s fluoropiridinskimi ligandi : diplomsko delo univerzitetnega študijskega programa I. stopnjeAljaž Klavžar, 2024, undergraduate thesis Abstract: Diplomsko delo je bilo osredotočeno na sintezo in karakterizacijo bakrovih koordinacijskih spojin, pri čemer smo uporabili bakrove soli kot vir bakra ter fluoropiridine, kateri so prevzeli vlogo ligandov.
V eksperimentalnem delu je bilo izdelanih veliko različnih vzorcev, le pri nekaterih pa so izpadli lepi kristali, katere smo kasneje karakterizirali. Uspelo nam je sintetizirati že znano spojino tetrakis(mu-2-Acetato)-bis(aqua-copper(ii)) (CUAQAC), katere kristali so nastali pri veliko različnih variacijah bakrovih soli ter izbranih fluoropiridinov. Nastalo je tudi nekaj na pogled obetavnih kristalov, pri katerih se je izkazalo, da gre za bakrovo sol, kar smo tudi šteli kot del ugotovitev. Poleg navedenih komponent, je bila pomembna tudi izbira topila, saj je topnost reagentov močno vplivala na dobljeni končni produkt.
Uporabljena metoda za sintezo je bila mešanje pri sobni temperaturi, metodi za karakterizacijo pa so bili rentgenska monokristalna analiza, ki nam je pomagala pri določitvi strukture kristalov, ter termogravimetrična analiza (TGA), ki nam je opisala spremembo mase vzorca v odvisnosti od temperature.
Keywords: baker, koordinacijske spojine, fluoropiridin, termogravimetrična analiza, rentgenska monokristalna analiza
Published in DKUM: 16.09.2024; Views: 8; Downloads: 47
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6. Sinteza ternarnih kadmijevih halkogenidov s planetarnim mikromlinom : diplomsko delo univerzitetnega študijskega programa I. stopnjeJona Kunej, 2024, undergraduate thesis Abstract: Ternarni kadmijevi halkogenidi, kot so CdSexTe1-x, CdSxSe1-x in CdTexS1-x, so osnova sodobnih elektronskih naprav. Uporabljajo se kot laserji, fotodetektorji, v sončnih celicah, v piezoelektroniki, v svetlečih diodah, itd. Kvartarni halkogenid CdSxTexSe1-2x ima številne zanimive aplikacije zaradi svojih edinstvenih optoelektronskih lastnosti. Tako kot ternarni kadmijevi halkogenidi, se tudi CdSxTexSe1-2x uporablja v fotovoltaiki, zaradi svojih sposobnosti absorbiranja širokega spektra sončne svetlobe in učinkovite pretvorbe te energije v električno energijo, v svetlečih diodah in drugih optoelektronskih napravah, zaradi visoke fotoluminiscence, v različnih vrstah senzorjev in v termoelektričnih napravah.
Pri diplomskem delu smo uporabljali mehanokemijsko sintezo, ki se v zadnjem času uporablja vse več. Z mehanokemijsko metodo, z uporabo planetarnega mikromlina, smo sintetizirali ternarne kadmijeve halkogenide (CdSexTe1-x, CdSxSe1-x, CdTexS1-x) in kvartarni kadmijev halkogenid CdSxTexSe1-2x. Spreminjali smo pogoje uporabljene v predhodnih raziskavah ter ugotavljala kako le-ti vplivajo na sintezo nanodelcev. Karakteristike sintetiziranih nanodelcev smo po koncu sinteze preverili z rentgensko praškovno difrakcijo, z dinamičnim sipanjem svetlobe, z diferenčno dinamično kalorimetrijo in s transmisijsko elektronsko mikroskopijo.
Keywords: nanomateriali, ternarni kadmijevi halkogenidi, mehanokemisjka sinteza, planetarni mikromlin, karakterizacijske metode
Published in DKUM: 12.09.2024; Views: 27; Downloads: 87
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7. Sinteza magnetno zeolitnega nanokompozita : magistrsko deloMelissa Sterniša, 2024, master's thesis Abstract: Magistrsko delo zajema sinteze magnetnih nanodelcev in sinteze magnetno zeolitnih nanokompozitov. Magnetni nanodelci so bili sintetizirani z metodo koprecipitacije oz. s soobarjalno metodo in mikrovalovno metodo. Magnetno zeolitni nankompoziti so nastali z naknadno sintezo in sočasno sintezo. Dobljeni produkti so bili okarakterizirani s Fourierjevo transformirano infrardečo spektroskopijo na oslabljen totalni odboj (ATR-FTIR), termogravimetrično analizo (TGA), dinamičnim sipanjem svetlobe (DLS), Brunauer-Emmett-Tellerjevo metodo (BET), vrstičnim elektronskim mikroskopom (SEM) in rentgensko praškovno difrakcijo (RTG). Rezultati karakterizacijskih metod so pokazali, da je bila uspešnejša sinteza magnetno zeolitnega nanokompozita z naknadno sintezo tako pri soobarjalnih magnetnih nanodelcih kot tudi pri mikrovalovnih. Sintetizirani magnetni nanodelci in nanokompoziti so bili nato še uporabljeni za odstranjevanje mikro in nanoplastike iz vode. Odstranjevanje je potekalo s pomočjo ultrazvočne kopeli in posedanjem na magnetu iz modelne raztopine polietilena. UV/VIS spektroskopija je pokazala, da je bilo najuspešnejše odstranjevanje z magnetnimi nanodelci sintetiziranimi s soobarjalno sintezo.
Keywords: Magnetni nanodelci, zeolit, magnetno zeolitni nanokompozit, mikro in nanoplastika
Published in DKUM: 11.09.2024; Views: 16; Downloads: 38
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8. Korozijske lastnosti cirkonija v umetni slini z dodatkom organskih in ortofosforne kisline : diplomsko delo visokošolskega strokovnega študijskega programa I. stopnjeLaura Kobe Stožinič, 2024, undergraduate thesis Abstract: Zaradi vse pogostejše uporabe cirkonijevih implantatov, je bil namen diplomske naloge raziskati korozijske lastnosti cirkonija v umetni slini z dodatkom organskih in ortofosforne kisline.
Osnovna raztopina, ki je služila kot agresivni medij, je bila umetna slina v prisotnosti najpogostejših kislin, ki jih vnašamo v ustno votlino s hrano in pijačo. Kisline, ki smo jih glede na priporočene dnevne vnose dodajali umetni slini, so bile različne organske: vinska, jabolčna in mlečna ter ortofosforna kislina.
Eksperimentalni del smo izvedli z gravimetrično metodo, pri temperaturi 37 °C, kar je optimalna telesna temperatura človeka in pri atmosferskem tlaku 101,3 kPa, na ta način smo se čim bolj približali pogojem v ustni votlini. Pred samim postopkom gravimetrije smo pripravili raztopino umetne sline s preračunanimi količinami organskih in ortofosforne kisline. Sam postopek gravimetrije je vključeval naslednje korake: vzorce, ki smo jih termostatirali smo predhodno ustrezno pripravili, kar je zajemalo postopke brušenja, poliranja, razmastitve, ultrazvočnega čiščenja in sušenja s komprimiranim zrakom. Tako pripravljene vzorce smo stehtali in termostatirali v raztopinah 24, 48, 72 in 96 h. Po pretečenem času smo korodirane vzorce ponovno ustrezno očistili in stehtali. Na podlagi spremembe mase vzorca pred in po izpostavitvi raztopini smo izračunali korozijsko hitrost. Tako smo ugotovili, katera kislina povzroča največje korodiranje cirkonija oziroma v kateri kislini je cirkonij najbolj odporen in tvori stabilen pasivni film. Z vrstičnim elektronskim mikroskopiranjem smo posneli površine nekaterih vzorcev.
Po 24, 48, 72 in 96 urni pasivaciji, so rezultati pokazali, da na spološno cirkonij tvori najbolj stabilen pasivni film v raztopini umetne sline z dodatkom jabolčne kisline. Najmanj odporen je v raztopini umetne sline z dodatkom mlečne kisline do 48 ur pasivacije, po 48 urah pa korozijske hitrosti cirkonija v raztopini umetne sline z dodatkom mlečne kisline padajo, medtem, ko v raztopini umetne sline z dodatkom vinske kisline naraščajo. Izračunane korozijske hitrosti so v splošnem nizke, kar pomeni, da je cirkonij v kovinski obliki glede korozije primeren material za medicinske vsadke.
Keywords: cirkonij, umetna slina, dentalni implantati, korozija, organske kisline, ortofosforna kislina
Published in DKUM: 10.09.2024; Views: 63; Downloads: 30
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9. Thermal study of APTES-functionalized magnetite nanoparticles with citric acid and polyacrylic acid for advanced forward osmosis systemsMatjaž Kristl, Urška Ostroško, Irena Ban, Irena Petrinić, Janja Stergar, 2024, original scientific article Abstract: Iron-based magnetic nanoparticles (MNPs) have attracted considerable attention as promising draw solutes in forward osmosis processes due to various advantages. In the present study, magnetite (Fe3O4) nanoparticles (MNPs) with diameters in the range of 12±2 nm were synthesized by applying the coprecipitation method and stabilized using (3-aminopropyl) triethoxysilane (APTES). The amino groups of APTES were further functionalized with various amounts of citric acid (CA) and poly(acrylic acid) (PAA) to achieve higher osmotic pressure. The as-prepared and functionalized nanoparticles were characterized using diferent methods: Fourier-transform infrared spectroscopy (FTIR) confrmed the binding of APTES and CA/PAA on the surface of the MNPs, while the size of the particles was determined by transmission electron microscopy (TEM) and X-ray powder difraction. The isoelectric point, zeta potential, and the particle size in suspension were determined by dynamic light scattering (DLS)/zeta potential measuring system. The amount of free –COOH groups was determined by conductometric titrations. The amount of organic matter (APTES, CA, and PAA) bound on the surface was determined by thermogravimetric analysis (TG), giving results between 7.6% for samples stabilized with APTES only and 17.5% for samples functionalized with APTES+PAA. TG provides a simple and efcient method for determining the amount of organic compounds bound to the surface of MNPs. The osmotic pressure measurements of double-layer coated MNPs provided encouraging results of up to 28 bar, enabling using the samples as draw solutions in an experimental forward osmosis system.
Keywords: magnetic nanoparticles, magnetite, citrit acid, poly(acrylic acid), forward osmosis
Published in DKUM: 14.08.2024; Views: 105; Downloads: 80
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10. Harnessing magnetic nanoparticles for the effective removal of micro- and nanoplastics : a critical reviewSabina Vohl, Matjaž Kristl, Janja Stergar, 2024, review article Abstract: The spread of micro- (MPs) and nanoplastics (NPs) in the environment has become a
significant environmental concern, necessitating effective removal strategies. In this comprehensive
scientific review, we examine the use of magnetic nanoparticles (MNPs) as a promising technology for
the removal of MPs and NPs from water. We first describe the issues of MPs and NPs and their impact
on the environment and human health. Then, the fundamental principles of using MNPs for the
removal of these pollutants will be presented, emphasizing that MNPs enable the selective binding
and separation of MPs and NPs from water sources. Furthermore, we provide a short summary of
various types of MNPs that have proven effective in the removal of MPs and NPs. These include
ferromagnetic nanoparticles and MNPs coated with organic polymers, as well as nanocomposites and
magnetic nanostructures. We also review their properties, such as magnetic saturation, size, shape,
surface functionalization, and stability, and their influence on removal efficiency. Next, we describe
different methods of utilizing MNPs for the removal of MPs and NPs. We discuss their advantages,
limitations, and potential for further development in detail. In the final part of the review, we provide
an overview of the existing studies and results demonstrating the effectiveness of using MNPs for
the removal of MPs and NPs from water. We also address the challenges that need to be overcome,
such as nanoparticle optimization, process scalability, and the removal and recycling of nanoparticles
after the completion of the process. This comprehensive scientific review offers extensive insights
into the use of MNPs for the removal of MPs and NPs from water. With improved understanding
and the development of advanced materials and methods, this technology can play a crucial role in
addressing the issues of MPs and NPs and preserving a clean and healthy environment. The novelty
of this review article is the emphasis on MNPs for the removal of MPs and NPs from water and a
detailed review of the advantages and disadvantages of various MNPs for the mentioned application.
Additionally, a review of a large number of publications in this field is provided.
Keywords: magnetic nanoparticles, microplastics, nanoplastics, water treatment, removal
Published in DKUM: 22.07.2024; Views: 166; Downloads: 29
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