TY - JOUR AU - Chodkowski, Michał AU - Terpiłowski, Konrad AU - Románszki, Loránd AU - Klébert, Szilvia AU - Mohai, Miklós AU - Károly, Zoltán TI - Effect of Non‐Thermal Sulfur Hexafluoride Cold Plasma Modification on Surface Properties of Polyoxymethylene JF - CHEMPHYSCHEM: A EUROPEAN JOURNAL OF CHEMICAL PHYSICS AND PHYSICAL CHEMISTRY J2 - CHEMPHYSCHEM PY - 2024 PG - 14 SN - 1439-4235 DO - 10.1002/cphc.202300709 UR - https://m2.mtmt.hu/api/publication/34762097 ID - 34762097 AB - X‐ray photoelectron spectroscopy was employed to reveal the differences in the chemical structure of the topmost layer after plasma modification. It was found out that changes in the surface properties of the polymer could be observed even after 20 seconds of treatment. The surface becomes hydrophobic or superhydrophobic, with the water contact angles up to 160 degrees. Morphological changes and increased roughness can be observed only in the nanoscale, whereas the structure seems to be unaffected in the microscale. As a result of plasma modification a permanent hydrophobic effect was obtained on the polyoxymethylene surface. LA - English DB - MTMT ER - TY - JOUR AU - Fronczak, Maciej AU - Károly, Zoltán AU - Banković, Predrag AU - Mojović, Zorica TI - The influence of precursor selection on electrochemical properties of radiofrequency thermal plasma synthesized graphene JF - MICROCHEMICAL JOURNAL J2 - MICROCHEM J VL - 199 PY - 2024 PG - 10 SN - 0026-265X DO - 10.1016/j.microc.2024.110079 UR - https://m2.mtmt.hu/api/publication/34561545 ID - 34561545 LA - English DB - MTMT ER - TY - JOUR AU - Bódis, Eszter AU - Károly, Zoltán TI - Zirconia-Toughened Alumina (ZTA) Nanoceramics with a Gradient Microstructure: A Comparative Study of ZTA Ceramics with Fibrous and Granular Morphology JF - MICROMACHINES J2 - MICROMACHINES-BASEL VL - 14 PY - 2023 IS - 9 PG - 15 SN - 2072-666X DO - 10.3390/mi14091681 UR - https://m2.mtmt.hu/api/publication/34125469 ID - 34125469 AB - ZrO2-toughened Al2O3 (ZTA) ceramic composites with a porosity gradient and with improved mechanical properties have a wide range of possible applications. We fabricated nanofibrous and nanogranular Y-ZTA and Ce-ZTA composites with a gradient microstructure by creating a temperature gradient during SPS sintering, with the use of asymmetric graphite tool arrangement (ASY). In this study, we examined the morphology effect of the starting materials on the sintering process and on the final microstructure, as well as the mechanical properties of the composites. A large temperature difference was established for both the granular and fibrous samples fabricated in the ASY configuration, which resulted in gradient porosity along the ceramics bodies: the upper part of the ceramics showed a highly porous fine microstructure, while the opposite side was highly densified. The final microstructure of the composites can be tailored by varying the morphology of the starting ceramics or the graphite configuration. A highly porous skeleton-like structure was formed by sintering fibres in the ASY configuration, whereas the granular precursors resulted in a much less porous composite. The microstructure affected the mechanical properties of the composite. Improved hardness and more than 50% higher compression strength were obtained for the granular Ce-ZTA samples as compared to the fibrous sample. Gradient porosity with fibrous or granular morphology promotes the penetration of bioactive nanosized hydroxyapatite (HAp) into the pore structure. Fibrous ZTA absorbs HAp more effectively due to its higher porosity as well as its bimodal pore structure. LA - English DB - MTMT ER - TY - JOUR AU - Martiz Chalen, Jose Alejandro AU - Károly, Zoltán AU - Nagyné Bereczki, Laura AU - Trif, László AU - Farkas, Attila AU - Kállay-Menyhárd, Alfréd AU - Kótai, László TI - Carbonization of Zr-loaded thiourea-functionalized styrene-divinylbenzene copolymers: An easy was to synthesize Nano-ZrO2@C and Nano-(ZrC, ZrO2)@C composites JF - JOURNAL OF COMPOSITES SCIENCE J2 - J COMPOSITES SCI VL - 7 PY - 2023 PG - 15 SN - 2504-477X DO - 10.3390/jcs7080306 UR - https://m2.mtmt.hu/api/publication/34077482 ID - 34077482 N1 - Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok krt. 2, Budapest, H-1117, Hungary Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, Műegyetem rakpart 3, Budapest, H-1111, Hungary Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rakpart 3, Budapest, H-1111, Hungary Deuton-X Ltd, Selmeci u. 89, Érd, H-2030, Hungary Export Date: 4 September 2023 Correspondence Address: Kótai, L.; Institute of Materials and Environmental Chemistry, Magyar Tudósok krt. 2, Hungary; email: kotai.laszlo@ttk.hu LA - English DB - MTMT ER - TY - PAT AU - Bódis, Eszter AU - Fazekas, Péter AU - Károly, Zoltán AU - Keszler, Anna Mária AU - Klébert, Szilvia AU - Kótai, László AU - Szépvölgyi, János TI - Eljárás mikroméretű nikkel-cink-ferrit (NixZn1-xFe2O4, 0 < x < 1) előállítására CY - Country:10001(1) PY - 2023 UR - https://m2.mtmt.hu/api/publication/33620312 ID - 33620312 AB - Jelen találmány tárgya eljárás nikkel-cink-ferrit (NixZn1-xFe2O4, 0