21. Accuracy of measurements of thermophysical parameters by dual-beam thermal-lens spectrometryVladislav R. Khabibullin, Mladen Franko, Mikhail A. Proskurnin, 2023, izvirni znanstveni članek Opis: Thermal-lens spectrometry is a sensitive technique for determination of physicochemical
properties and thermophysical parameters of various materials including heterogeneous systems
and nanoparticles. In this paper, we consider the issues of the correctness (trueness) of measurements
of the characteristic time of the thermal-lens effect and, thus, of the thermal diffusivity determined
by dual-beam mode-mismatching thermal lensing. As sources of systematic errors, major factors—
radiation sources, sample-cell and detector parameters, and general measurement parameters—are
considered using several configurations of the thermal-lens setups, and their contributions are
quantified or estimated. Furthermore, with aqueous ferroin and Sudan I in ethanol as inert colorants,
the effects of the intermolecular distance of the absorbing substance on the correctness of finding the
thermophysical parameters are considered. The recommendations for checking the operation of the
thermal-lens setup to ensure the maximum accuracy are given. The results obtained help reducing
the impact of each investigated factor on the value of systematic error and correctly measure the
thermophysical parameters using thermal-lens spectrometry.
Ključne besede: thermal-lens spectrometry, accuracy, trueness, mode-mismatched schematic, measurements of thermal diffusivity
Objavljeno v RUNG: 20.01.2023; Ogledov: 2320; Prenosov: 16
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22. Recent progress and applications of thermal lens spectrometry and photothermal beam deflection techniques in environmental sensingMladen Franko, Leja Goljat, Mingqiang Liu, Hanna Budasheva, Mojca Žorž, Dorota Korte, 2023, izvirni znanstveni članek Opis: This paper presents recent development and applications of thermal lens microscopy (TLM) and beam deflection spectrometry (BDS) for the analysis of water samples and sea ice. Coupling of TLM detection to a microfluidic system for flow injection analysis (µFIA) enables the detection of microcystin-LR in waters with a four samples/min throughput (in triplicate injections) and provides an LOD of 0.08 µg/L which is 12-times lower than the MCL for microcystin-LR in water. µFIA-TLM was also applied for the determination of total Fe and Fe(II) in 3 µL samples of synthetic cloudwater.
The LODs were found to be 100 nM for Fe(II) and 70 nM for total Fe. The application of µFIA-TLM for the determination of ammonium in water resulted in an LOD of 2.3 µM for injection of a 5 µL sample and TLM detection in a 100 µm deep microfluidic channel. For the determination of iron
species in sea ice, the BDS was coupled to a diffusive gradient in the thin film technique (DGT). The 2D distribution of Fe(II) and total Fe on DGT gels provided by the BDS (LOD of 50 nM) reflected the distribution of Fe species in sea ice put in contact with DGT gels.
Ključne besede: thermal lens microscopy, beam deflection spectrometry, microfluidic system, microcystin-LR detection, iron species determination, ammonium detection
Objavljeno v RUNG: 03.01.2023; Ogledov: 2900; Prenosov: 41
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23. Synthesis of bio-composite sustainable materials and their applications in environmental technologyMladen Franko, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje) Opis: Organic wastes such as wood, hair, feathers, exoskeletons of crustaceans and molluscs or even water melon rind represent some examples of valuable and abundant sources of natural polymers such as cellulose, keratin and chitin, which were already extensively exploited for preparation of novel bio-composite materials. Application of green chemistry approaches for their synthesis makes such bio-composites really sustainable materials with several interesting properties for different applications, including those in environmental technology. In this review, synthesis of novel bio-composites based on cellulose (CEL), chitosan (CS - chemically modified chitin) or keratin (KER) and their potential for application in environmental technology will be presented.
The synthesis is based on dissolution of bio-polymers in ionic liquids. This is the crucial step in the synthesis of such materials, which at the same time makes the process completely recyclable with regard to the solvents. The tensile strength is regulated by the proportion of CEL in the material, while higher proportions of CS were shown to add to the adsorptive and antimicrobial activity of the material [1]. Antimicrobial activity was also observed for CEL:KER materials and was further improved by decorating the bio-composites with silver or gold nanoparticles [2].
Our research has shown high potential for application of synthesised bio-composites in environmental technologies including removal of toxins or killing of pathogens in water. It was demonstrated that CEL:CS composites can remove up to 96 mg of microcystin per gram of composite, which is almost 5 times higher than best known adsorbent for microcystin [1]. On the other hand CEL:KER composites with incorporated Ag0 nanoparticles have shown up to 6 logs of reduction in the number of bacteria (99.9999% growth reduction) of bacteria such as E. coli which is a frequently encountered pathogen in wastewaters [2].
[1] TRAN, C. D., DURI, S., DELNERI, A., FRANKO, M. (2013), Chitosan-cellulose composite materials: preparation, characterization and application for removal of microcystin, Journal of hazardous materials. 252/253, p 355-366
[2] TRAN, C. D., PROSENC, F., FRANKO, M., BENZI, G. (2016, One-pot synthesis of biocompatible silver nanoparticle composites from cellulose and keratin: characterization and antimicrobial activity, ACS applied materials & interfaces. 8, p 34791-34801
Ključne besede: Trajnostni materiali, biokompoziti, celuloza, hitosan, keratin, sporopolenin, mikrocistin
Objavljeno v RUNG: 06.12.2022; Ogledov: 3509; Prenosov: 0
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24. Amoxicillin doped hyaluronic acid/fucoidan multifunctional coatings for medical grade stainless steel orthopedic implantsMatej Bračič, Sanja Potrč, Matjaž Finšgar, Lidija Gradišnik, Uroš Maver, Hanna Budasheva, Dorota Korte, Mladen Franko, Lidija Fras Zemljič, 2023, izvirni znanstveni članek Ključne besede: orthopedic implant, medical grade stainless steel, amoxicillin, hyaluronic acid, fucoidan, multifunctional coating
Objavljeno v RUNG: 21.11.2022; Ogledov: 3001; Prenosov: 9
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27. Characterization of smart and biocompatible materials based on chitosan:cellulose composites containing sporopollenin exine capsulesHanna Budasheva, Patricia Cazon Diaz, Dorota Korte, Mladen Franko, 2022, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: chitosan:cellulose composites, biocompatible materials, beam deflection spectrometry, porosity determination, structural characterisation, thermal properties
Objavljeno v RUNG: 30.06.2022; Ogledov: 2398; Prenosov: 69
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30. Resolucija o nacionalnem programu visokega šolstva do 2030Zdravko Kačič, Igor Papič, Klavdija Kutnar, Mladen Franko, Ludvik Toplak, Blaž Nardin, Gregor Polančič, Peter Purg, Omar Smajlović, Boštjan Zalar, Boštjan Gorjup, 2022, elaborat, predštudija, študija Ključne besede: visoko šolstvo, Republika Slovenija, nacionalni programi
Objavljeno v RUNG: 17.05.2022; Ogledov: 2686; Prenosov: 0
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