20.500.12556/RUL-158503 Surface modification of copper-based flakes for conductive polymer composites The physical properties as well as thermal and electrical stability of copper particles can be improved by surface protection, which mainly depends on the coating material. Our study was, therefore, focused on the rheological, thermal, mechanical and electrical characterization of polymer composites by comparing uncoated (Cu), silver-coated (Cu@Ag) and silica-coated (Cu@Si) copper flakes in low-density polyethylene at various volume concentrations (up to 40%). Interactions among particles were investigated by rheological properties, as these indicate network formation (geometrical entanglement), which is important for mechanical reinforcement as well as establishing an electric pathway (electrical percolation). The results showed that geometrical and electrical percolation were the same for Cu and Cu@Si, ~15%, while, surprisingly, Cu@Ag exhibited much lower percolation, ~7.5%, indicating the fusion of the Ag coating material, which also decreased crystal growth (degree of crystallinity). Furthermore, the magnitude of the rheological and mechanical response remained the same for all investigated materials, indicating that the coating materials do not provide any load transfer capabilities. However, they profoundly affect electron transfer, in that, Cu@Ag exhibited superior conductivity (74.4 S/m) compared to Cu (1.7 × 10$^{−4}$ S/m) and Cu@Si (1.5 × 10$^{−10}$ S/m). The results obtained are important for the design of advanced polymer composites for various applications, particularly in electronics where enhanced electrical conductivity is desired. polymer composites copper flakes silver coating silica coating percolation threshold rheological properties thermal properties mechanical properties electrical properties polimerni kompoziti bakrene luske srebrna prevleka silicijeva prevleka perkolacijski prag reološke lastnosti termične lastnosti mehanske lastnosti električne lastnosti true false true Angleški jezik Slovenski jezik Članek v reviji 2024-06-14 10:29:18 2024-06-14 10:29:20 2025-02-01 04:06:23 0000-00-00 00:00:00 2024 0 0 14 str. iss. 12, art. 1620 Vol. 16 Jun. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 539.3:678 2073-4360 10.3390/polym16121620 198896899 polymers-16-01620-v2.pdf polymers-16-01620-v2.pdf 1 A60D3F8F3E281A7D90F0E4CA5ED695DC 4a0c066795a53bc9b589ea97b1be077f7c06c16c6836eb14d2c5c7729e22d5b2 05c28abc-dfc9-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=199003 https://www.mdpi.com/2073-4360/16/12/1620 1 351e1fb3-2a28-11ef-86fa-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=186161 Fakulteta za strojništvo 0 0 0