1. High oxygen barrier chitosan films neutralized by alkaline nanoparticlesUrška Jančič, Mojca Božič, Silvo Hribernik, Tamilselvan Mohan, Rupert Kargl, Karin Stana-Kleinschek, Selestina Gorgieva, 2021, original scientific article Abstract: The most frequent neutralisation procedure, applied on chitosan (CS) films includes treatment with NaOH base. Such treatment endows CS films with stability in water, yet, same can significantly decrease the film performance. In the present paper, we investigate Mg(OH)2 nanoparticles as a neutralisation agent for CS solutions followed by casting into films. This is combined and compared with classical casting and film drying from nonneutralized solutions followed by NaOH treatment after film formation. The influence on the properties of resulting films is investigated in detail and large differences are found for structure and barrier properties. The stable, opaque-to-transparent CS films (depending on Mg(OH)2 content and post-treatment) were obtained by facile casting method of neat CS or CS–Mg(OH)2 dispersions, in the complete absence of cross-linkers and plasticizers. FTIR data demonstrate
the Mg(OH)2 and NaOH deprotonation effect, and strongly suggest intensive H-bonding interaction between CS and Mg(OH)2. X-ray photoelectron spectroscopy showed differences in the hydroxide content and protonation of CS nitrogen. The reduction of surface roughness and increase of homogeneity, the tensile strength and elongation, as well as thermal stability and excellent oxygen barrier properties were measured for CS enclosing the Mg(OH)2 nanoparticles. Further treatment with 1 M NaOH causes repacking of CS polymer chains, improving the crystallinity and water vapour barrier properties, degrading the mechanical properties by increasing the films brittleness and increasing the char formation due to reduced thermal stability.
Keywords: CS films, Mg(OH)2, neutralization, oxygen barrier properties
Published in DKUM: 14.10.2025; Views: 0; Downloads: 2
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2. Investigation of the influencing parameters of the ▫$H_2O_2-assisted$▫ photochemical treatment of waste liquid from the hydrothermal carbonization process in a microreactor flow systemAleksandra Petrovič, Tjaša Cenčič, Silvo Hribernik, Andreja Nemet, 2025, original scientific article Abstract: Due to its complex composition and toxicity, the waste liquid from hydrothermal carbonization (HTC) poses a serious environmental challenge that must be addressed before disposal. In this study, the photochemical treatment of HTC liquid in a microreactor flow system was investigated. The effects of wavelength, the presence of atmospheric oxygen, oxidizing agent (H2O2) and catalyst (FeSO4), residence time and pH on the efficiency of the photo-treatment were investigated. In addition, the influence of the addition of deep eutectic solvent (DES) on photo-treatment was studied. The results showed that the photochemical treatment was more efficient at 365 nm than at 420 nm, and that the acidic conditions gave better results than the basic ones. UV365 treatment in the presence of H2O2 (at a dosage of 1 vol%) resulted in removal efficiencies of 31.6% for COD, 17.6% for TOC, 16.9% for NH4-N and 17.2% for PO4-P. The addition of FeSO4 caused coagulation/flocculation effects, but improved phosphorus removal. The addition of DES resulted in slight discolouration of the liquid and proved unsuccessful in COD removal. The GC-MS analysis and 3D-EEM spectra showed significant changes in the fate of organics and in the fluorescence intensity of aromatic proteins and humic acid-like substances. Photochemical treatment in a microreactor flow system in the presence of H2O2 under the selected operating conditions reduced the content of organics and nutrients in the HTC liquid, but the process liquids still showed toxic effects on the organisms V. fischeri and Daphnia magna.
Keywords: hydrothermal treatment, waste process liquid, photochemical treatment, hydrogen peroxide, microreactor flow system
Published in DKUM: 25.09.2025; Views: 0; Downloads: 4
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3. Metallisation of textiles and protection of conductive layers: An overview of application techniquesAlenka Ojstršek, Olivija Plohl, Selestina Gorgieva, Manja Kurečič, Urška Jančič, Silvo Hribernik, Darinka Fakin, 2021, review article Abstract: The rapid growth in wearable technology has recently stimulated the development of
conductive textiles for broad application purposes, i.e., wearable electronics, heat generators, sensors,
electromagnetic interference (EMI) shielding, optoelectronic and photonics. Textile material, which
was always considered just as the interface between the wearer and the environment, now plays
a more active role in different sectors, such as sport, healthcare, security, entertainment, military,
and technical sectors, etc. This expansion in applied development of e-textiles is governed by a
vast amount of research work conducted by increasingly interdisciplinary teams and presented
systematic review highlights and assesses, in a comprehensive manner, recent research in the field of
conductive textiles and their potential application for wearable electronics (so called e-textiles), as
well as development of advanced application techniques to obtain conductivity, with emphasis on
metal-containing coatings. Furthermore, an overview of protective compounds was provided, which
are suitable for the protection of metallized textile surfaces against corrosion, mechanical forces,
abrasion, and other external factors, influencing negatively on the adhesion and durability of the
conductive layers during textiles’ lifetime (wear and care). The challenges, drawbacks and further
opportunities in these fields are also discussed critically.
Keywords: metallization, conductive textiles, e-textiles, coatings techniques, protective coatings, durability
Published in DKUM: 16.06.2025; Views: 0; Downloads: 10
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4. New approach for adsorptive removal of the antibiotic ciprofloxacin: carboxymethyl-dextran-functionalised magnetic iron oxide nanomaterialsErik Mihelič, Lidija Fras Zemljič, Marjana Simonič, Sašo Gyergyek, Alenka Vesel, Silvo Hribernik, Matej Bračič, Ivan Anžel, Olivija Plohl, 2025, original scientific article Abstract: Antibiotic residues in environmental media pose a significant health, social and economic problem and require effective removal strategies. This study presents a novel approach for the removal of the antibiotic ciprofloxacin from water sources using magnetic iron oxide nanoparticles (MNPs) synthesised by co-precipitation, and subsequently functionalised with the polysaccharide carboxymethyl-dextran (CMD). The prepared nanoadsorbent was characterised extensively by various physicochemical analyses, to evaluate its morphology, crystal structure, surface chemistry, electrokinetic properties, thermogravimetric properties and magnetic features. These analyses confirmed the successful functionalisation of the MNPs with CMD highlighting its potential for effective adsorption applications. The stability of CMD coating on MNPs was evaluated in terms of total carbon content, an important, yet often overlooked factor. The adsorption performance of MNPs@CMD for ciprofloxacin was investigated systematically by studying the effects of adsorbent dosage, pH, initial ciprofloxacin concentration, ionic strength, adsorption time and kinetics, temperature, and reusability. Under optimal conditions, nanoadsorbent exhibited a satisfactory maximum adsorption capacity of 14.71 mg/g, and maintained a removal eff iciency of 79 % after four cycles, with minimal desorption of CMD layer on the MNPs. These findings demonstrate the potential of this magnetic polysaccharide nanoadsorbent for effective removal of ciprofloxacin from aqueous environments, enabling magnetic recovery and reuse.
Keywords: Carboxymethyl-dextran-MNPs, ciprofloxacin, adsorption
Published in DKUM: 26.05.2025; Views: 0; Downloads: 18
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5. 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: 19
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6. 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: 11
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7. 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: 19
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8. 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: 83
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9. 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: 26
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10. 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: 38
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