1. Sustainable hydrothermal co-carbonization of residues from the vegetable oil industry and sewage sludge : hydrochar production and liquid fraction valorisationAleksandra Petrovič, Tjaša Cenčič, Jelena Parlov Vuković, Tomislav Jednačak, Silvo Hribernik, Sabina Vohl, Danijela Urbancl, Marina Tišma, Lidija Čuček, 2024, izvirni znanstveni članek Opis: In this study, the hydrothermal co-carbonization (co-HTC) of residues from the vegetable oil industry (pumpkin oil cake– PC, hemp oil cake– HC) and sewage sludge (SS) was investigated for the first time. The co-HTC was performed at 250 C and atreatment time of 5 h. The effects of the mass ratio of the feedstocks (1:1, 1:3 and 3:1) on the properties of the HTC products were investigated using various analytical methods (NMR, XRD, 3D-EEM, FTIR, etc.). The co-HTC of SS with oil cakes resulted in improved fuel properties of the hydrochar and an increase in C content from 36.9 to 53.7 wt%, and an increase in the higher heating value (HHV) from 14.8 to 23.6 MJ/kg. The combination with HC gave hydrochars with a higher HHV and higher C content than the combination with PC. The hydrochar yield varied in the range of 39.4–55.3 wt%. NMR analysis revealed a higher proportion of aliphatic (~60 %) than aromatic compounds (~35 %) in the hydrochars, as well as a high content of orthophosphate and unsaturated fatty acids. The liquid fractions were rich in nutrients and organic compounds, but toxic to aquatic organisms. The hydrochars and liquid fractions performed well in the germination test with plant species.
Ključne besede: hydrothermal co-carbonization, sewage sludge, vegetable oil industry residues, hydrochar, liquid fraction, valorisation
Objavljeno v DKUM: 17.01.2025; Ogledov: 0; Prenosov: 4
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2. Grafična zasnova in tisk prevodne matrice za izdelavo senzorskih tekstilijTaja Kerčmar, 2024, diplomsko delo Opis: V okviru diplomskega dela smo izdelali fleksibilno mišično opornico, osnovano na fleksibilni pletenini z visoko stopnjo raztezka, katera služi kot nosilni substrat za dva sistema prevodnih matric, ki skupaj tvorita senzorski sistem in prevodne povezave za prenos signalov do konektorjev. Najprej smo se lotili grafičnega oblikovanja vzorca prevodnih linij in senzorske matrice za mišično opornico zasnovano v okviru projekta Wibrant. Po oblikovanju vzorca smo se lotili testnega tiska ravnih črt na hidrofobni papir, kjer smo bolj podrobno spoznali delovanje inkjet tiskalnika in preverili vpliv števila slojev nanosa tiskarskega fluida na električno upornost, čemur je sledil testni tisk na pletenino. Pri tem smo določili parametre tiskanja. Sledila je izvedba tiska grafičnega prevodnega vzorca in senzorske matrice na pletenino. Po uspešno izvedenem tisku smo natisnjene linije in vzorce fiksirali in izmerili električno upornost. Izvedena je bila še mikroskopska analiza natisnjenih vzorcev in analiza pralnih obstojnosti tiska. Določeni optimalni pogoji tiskanja s komercialnim prevodnim fluidom zagotavljajo zadovoljivo stopnjo prevodnosti in predstavlja osnovo za nadaljnji razvoj nosljivih tekstilnih senzorskih naprav.
Ključne besede: pametni tekstil, e-tesktil, prevodni materiali, inkjet tisk, prevodne paste, senzorske tekstilije, prevodnost
Objavljeno v DKUM: 19.07.2024; Ogledov: 245; Prenosov: 72
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3. Advance analysis of the obtained recycled materials from used disposable surgical masksAlen Erjavec, Julija Volmajer Valh, Silvo Hribernik, Tjaša Kraševac Glaser, Lidija Fras Zemljič, Tomaž Vuherer, Branko Neral, Mihael Brunčko, 2024, izvirni znanstveni članek Opis: The production of personal protective equipment (PPE) has increased dramatically in recent years, not only because of the pandemic, but also because of stricter legislation in the field of Employee Protection. The increasing use of PPE, including disposable surgical masks (DSMs), is putting additional pressure on waste collectors. For this reason, it is necessary to find high-quality solutions for this type of waste. Mechanical recycling is still the most common type of recycling, but the recyclates are often classified as low-grade materials. For this reason, a detailed analysis of the recyclates is necessary. These data will help us to improve the properties and find the right end application that will increase the value of the materials. This work represents an extended analysis of the recyclates obtained from DSMs, manufactured from different polymers. Using surface and morphology tests, we have gained insights into the distribution of different polymers in polymer blends and their effects on mechanical and surface properties. It was found that the addition of ear loop material to the PP melt makes the material tougher. In the polymer blends obtained, PP and PA 6 form the surface (affects surface properties), while PU and PET are distributed mainly inside the injection-molded samples.
Ključne besede: mechanical recycling, disposable surgical mask, morphology, surface properties, mechanical properties, nonwoven materials, PPE
Objavljeno v DKUM: 09.04.2024; Ogledov: 232; Prenosov: 15
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4. Pullulan-based films impregnated with silver nanoparticles from the Fusarium culmorum strain JTW1 for potential applications in the food industry and medicineMagdalena Wypij, Mahendra Rai, Lidija Fras Zemljič, Matej Bračič, Silvo Hribernik, Patrycja Golińska, 2023, izvirni znanstveni članek Opis: Introduction: Biopolymers, such as pullulan, a natural exopolysaccharide from Aureobasidium pullulans, and their nanocomposites are commonly used in the food, pharmaceutical, and medical industries due to their unique physical and chemical properties.
Methods: Pullulan was synthesized by the A. pullulans ATCC 201253 strain. Nanocomposite films based on biosynthesized pullulan were prepared and loaded with different concentrations of silver nanoparticles (AgNPs) synthesized by the Fusarium culmorum strain JTW1. AgNPs were characterized by transmission electron microscopy, Zeta potential measurements, and Fourier-transform infrared spectroscopy. In turn, the produced films were subjected to physico-chemical analyses such as goniometry, UV shielding capacity, attenuated total reflection–Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy, and their mechanical and degradation properties were assessed. The antibacterial assays of the nanoparticles and the nanocomposite films against both food-borne and reference pathogens, including Listeria monocytogenes, Salmonella infantis, Salmonella enterica, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, were performed using standard methods.
Results: AgNPs were small (mean 15.1 nm), spherical, and displayed good stability, being coated with protein biomolecules. When used in higher concentrations as an additive to pullulan films, they resulted in reduced hydrophilicity and light transmission for both UV-B and UV-A lights. Moreover, the produced films exhibited a smooth surface. Therefore, it can be concluded that the addition of biogenic AgNPs did not change the morphology and texture of the films compared to the control film. The nanoparticles and nanocomposite films demonstrated remarkable antibacterial activity against both food-borne and reference bacteria. The highest activity of the prepared films was observed against L. monocytogenes.
Discussion: The obtained results suggest that the novel nanocomposite films prepared from biosynthesized pullulan and AgNPs can be considered for use in the development of medical products and food packaging. Moreover, this is the first report on pullulan-based nanocomposites with mycogenic AgNPs for such applications.
Ključne besede: Aureobasidium pullulans, pullulan, nanocomposite films, silver nanoparticles, mycosynthesis, nanobiotechnology, applied microbiology, antibacterial activity
Objavljeno v DKUM: 08.09.2023; Ogledov: 469; Prenosov: 33
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5. Fabrication of polysaccharide-based halochromic nanofibers via needle-less electrospinning and their characterization: a study of the leaching effectBeste Elveren, Silvo Hribernik, Manja Kurečič, 2022, izvirni znanstveni članek Opis: Responsive materials, i.e., smart materials, have the ability to change their physical or chemical properties upon certain external signals. The development of nanofibrous halochromic materials, specifically combining the pH-sensitive functionality and unique nanofiber properties, could yield interesting new applications, especially when the common problem of dye leaching is successfully tackled. Therefore, in this article, we studied the fabrication process of polysaccharide-based halochromic nanofibrous materials by using a combination of various halochromic dyes (bromothymol blue, bromocresol green, and thymol blue) and cellulose acetate in a spinning solution using a one-pot strategy. The inhibition of leaching was addressed by using a complexing agent: poly-diallyl-dimethylammonium chloride (PDADMAC). The preparation of hybrid spinning solutions, their characterization, and ability to form continuous nanofibers were studied using a high production needle-less electrospinning system. The produced hybrid solutions and nanofibers were characterized, in terms of their rheological properties, chemical structure, morphology, and functionality. Fabricated nanofibrous halochromic structures show a clear color change upon exposure to different pH values, as well as the reduced leaching of dyes, upon the addition of a complexing agent. The leaching decreased by 61% in the case of bromocresol green, while, in the case of bromothymol blue and thymol blue, the leaching was reduced by 95 and 99%, respectively.
Ključne besede: halochromism, responsive polymers, polysaccharides, electrospinning
Objavljeno v DKUM: 31.07.2023; Ogledov: 424; Prenosov: 55
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9. Funkcionalizacija tekstilij z nano $TiO_2$ in $SiO_2$ prevlekamiNika Veronovski, Silvo Hribernik, Majda Sfiligoj-Smole, 2008, pregledni znanstveni članek Opis: Funkcionalizacija različnih materialov z uporabo prevlek iz nanodelcev je v zadnjem času predmet mnogih raziskav, vendar pa to tehnologijo na tekstilnem področju uporabljajo le v omejenem obsegu, in to kljub njenemu velikemu potencialu. Članek zajema pregled raziskav s področja nanoprevlek vlaken z delci titanovega in silicijevega dioksida, treba pa je poudariti, da so prevleke iz drugih anorganskih nanodelcev na vlaknih prav tako pomembne, saj z njimi dosegamo nove funkcionalne lastnosti tekstilij.
Ključne besede: nanotehnologija, nanoprevleke, $TiO_2$, nanodelci, $SiO_2$, $SiO_2$ nanodelci
Objavljeno v DKUM: 31.08.2017; Ogledov: 1137; Prenosov: 123
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10. Naravno obnovljiva rastlinska tekstilna vlaknaPetra Gašparič, Zala Urisk, Andreja Križanec, Marko Munda, Silvo Hribernik, Manja Kurečič, Tatjana Kreže, Majda Sfiligoj-Smole, 2012, pregledni znanstveni članek Opis: Zaradi čedalje globlje ekološke ozaveščenosti in okoljevarstvenih zahtev obravnavamo v sodobnem času izdelavo, uporabo in odstranjevanje materialov veliko bolj kritično. Naravna celulozna vlakna so v tem pogledu izkazala svojo kakovost in popolnoma izpolnila vse ekološke kriterije. Naravna celulozna vlakna uporabljamo za tekstilne in tekstilnotehnične namene. To so vlakna iz ličja stebel, ki tvorijo vlaknate snopiče v notranjem ličju stebel dvokaličnic, in listna vlakna, ki tečejo po dolžini listov enokaličnic, ter semenska vlakna in vlakna iz plodov. Lan, konopljo, juto, ramijo, sisal ter kokos uporabljamo predvsem za tehnične namene. V zadnjem času pa izjemno narašča zanimanje za obnovljive surovinske vire tudi na področju vlaken. V ospredju so vlakna rastlinskega izvora. Pri iskanju novih surovinskih virov se proučujejo številne rastline, ki ne spadajo med tradicionalne vire vlaken, da bi iz njihovih stebel ali listov izolirali vlakna uporabnih lastnosti. Pri izolaciji vlaken pridobimo tehnična vlakna, kar pomeni, da so celulozna vlakna večcelične strukture, pri katerih so posamezne celice vezane v snopiče. Poleg konvencionalnih načinov izolacije vlaken se uporabljajo tudi številni sodobni postopki, kot so biotehnološki z uporabo encimov, itd. Način, kako vlakna izoliramo, vpliva na površinsko morfologijo vlaken. V prispevku so predstavljena nekatera vlakna, ki jih pridobivamo iz kmetijskih odpadkov, kot so slama žitaric, listi ananasa, sladkorni trs, hmeljeva stebla, kinoa, vlakna iz različnih trav itd.
Ključne besede: tekstilna vlakna, celulozna vlakna, lignocelulozna vlakna, rastlinska vlakna, naravno obnovljiva vlakna, netradicionalna vlakna
Objavljeno v DKUM: 10.07.2015; Ogledov: 2716; Prenosov: 188
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