1. Synergic effect of large MXene nanosheets and protective coatings on improved electroconductivity and wash durability of MXene/polymer-modified cotton fabricLaura Jug, Silvo Hribernik, Alenka Ojstršek, 2025, original scientific article Abstract: E-textiles and their wearable analogues are finding applications in a myriad of sectors, ranging from sensors to health and sports applications. The development of a truly functional and reusable textile substrate presents a challenging task; its design encompasses the fabrication of optimal functional conductive particles, as well as devising strategies for their application that will ensure their functional properties (e.g. conductivity) are retained in an undiminished state for a foreseeable period. In the presented study, we tackled these two aspects in an interdependent way: i) The enhancement of the electrical conductivity of MXene-modified cotton fabric by increasing the lateral size of nanosheets during the Ti3C2TX synthesis, and ii) The improvement of washing durability of MXenes on the fabric surface by selecting suitable protective coatings. The results of Scanning Electron Microscopy (SEM), X-ray powder Diffraction (XRD), Dynamic Light Scattering (DLS) and Atomic Force Microscopy (AFM) revealed the successful synthesis of large and stable MXene nanosheets with ultrathin flakelike nanostructures, high colloidal stability and delamination yields. Using multiple application procedures of dipping and drying, the MXene nanosheets formed extensive adhesion areas on the cotton fabric and overlapped the fibre pores, thus reducing the interfacial resistance between the sheets and improving the coating uniformity and, consequently, increasing electrical conductivity. Weaker adhesion and depletion of large nanosheets were further effectively prevented by protective polymer coatings. The MXene-coated/protected fabrics had sufficient electrical conductivity, even after 20 laundering cycles. Moreover, the surface hydrophobicity was negligibly reduced, preventing water accessibility and, thus, increasing the oxidation stability of the applied MXenes.
Keywords: Ti3C2TX MXene, synthesis parameters, cotton fabric, electrical conductivity, protective coatings, washing durability
Published in DKUM: 10.03.2025; Views: 0; Downloads: 7
 Full text (8,43 MB)
This document has many files! More... |
2. Nisin-loaded gelatin microparticles for the enhanced bioactivity of bacterial nanocelluloseMaša Hren, Janja Trček, Aleksandra Šakanović, Hristina Obradović, Mateja Erdani-Kreft, Silvo Hribernik, Selestina Gorgieva, 2025, original scientific article Abstract: Bacterial nanocellulose (BnC) is of immense importance in medicine, although its lack of bioactivity present intriguing issue. We propose a method to modify BnC with gelatin and nisin biomolecules, and explore their synergistic effect on the antimicrobial activity. Gelatin microparticles (without/with nisin loading) with a size ~0.5 μm and ~ 1.3 μm were prepared by spray drying and stabilised by dehydrothermal treatment. Modified BnC-based membranes supported the formation of biologically relevant minerals and were non-cytotoxic to human gingival fibroblast cells (HGF). The presence of gelatin microparticles improved the viability of HGF by approximately 20 %, due to the effect of gelatin alone, independent of the addition of nisin. BnC coated with a nisin/gelatin solution reduces the viability of HGF by about 20 %, but this negative effect is not observed by nisin coated gelatin microparticles. The cell viability of BnC membranes was above 90 % in both porcine and human urothelial cells. The antimicrobial activity study confirmed an inhibitory effect of membranes modified with nisin-coated microparticles or a gelatin/nisin solution against Staphylococcus aureus at a non-cytotoxic nisin dose (150 μg/mL). The study demonstrates the structural effects of gelatin and gelatin/nisin mixtures on the bioactivity of BnC and provides a rationale for the modification procedure.
Keywords: bacterial nanocellulose, gelatin, nisin, spray-drying, antimicrobial function, bioactivity
Published in DKUM: 10.03.2025; Views: 0; Downloads: 4
Full text (7,52 MB)
This document has many files! More... |
3. 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, original scientific article Abstract: 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.
Keywords: hydrothermal co-carbonization, sewage sludge, vegetable oil industry residues, hydrochar, liquid fraction, valorisation
Published in DKUM: 17.01.2025; Views: 0; Downloads: 9
Full text (8,68 MB) |
4. Grafična zasnova in tisk prevodne matrice za izdelavo senzorskih tekstilijTaja Kerčmar, 2024, undergraduate thesis Abstract: 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.
Keywords: pametni tekstil, e-tesktil, prevodni materiali, inkjet tisk, prevodne paste, senzorske tekstilije, prevodnost
Published in DKUM: 19.07.2024; Views: 245; Downloads: 74
Full text (2,39 MB) |
5. 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, original scientific article Abstract: 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.
Keywords: mechanical recycling, disposable surgical mask, morphology, surface properties, mechanical properties, nonwoven materials, PPE
Published in DKUM: 09.04.2024; Views: 232; Downloads: 17
Full text (8,08 MB)
This document has many files! More... |
6. 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, original scientific article Abstract: 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.
Keywords: Aureobasidium pullulans, pullulan, nanocomposite films, silver nanoparticles, mycosynthesis, nanobiotechnology, applied microbiology, antibacterial activity
Published in DKUM: 08.09.2023; Views: 469; Downloads: 33
Full text (4,23 MB)
This document has many files! More... |
7. 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, original scientific article Abstract: 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.
Keywords: halochromism, responsive polymers, polysaccharides, electrospinning
Published in DKUM: 31.07.2023; Views: 424; Downloads: 57
Full text (5,54 MB)
This document has many files! More... |
8. |
9. |
10. |
