Accueil > articulos > Adjusting the Neel relaxation time of Fe3O4/ZnxCo1-xFe2O4 core/shell nanoparticles for optimal heat generation in magnetic hyperthermia
Resumen: In this work it is shown a precise way to optimize the heat generation in high viscosity magnetic colloids, by adjusting the Neel relaxation time in core/shell bimagnetic nanoparticles, for magnetic fluid hyperthermia (MFH) applications. To pursue this goal, Fe3O4/ZnxCo1-xFe2O4 core/shell nanoparticles were synthesized with 8.5 nm mean core diameter, encapsulated in a shell of similar to 1.1 nm of thickness, where the Zn atomic ratio (Zn/(Zn + Co) at%) changes from 33 to 68 at%. The magnetic measurements are consistent with a rigid interface coupling between the core and shell phases, where the effective magnetic anisotropy systematically decreases when the Zn concentration increases, without a significant change of the saturation magnetization. Experiments of MFH of 0.1 wt% of these particles dispersed in water, in Dulbecco modified Eagles minimal essential medium, and a high viscosity butter oil, result in a large specific loss power (SLP), up to 150 W g(-1), when the experiments are performed at 571 kHz and 200 Oe. The SLP was optimized adjusting the shell composition, showing a maximum for intermediate Zn concentration. This study shows a way to maximize the heat generation in viscous media like cytosol, for those biomedical applications that require smaller particle sizes. Idioma: Inglés DOI: 10.1088/1361-6528/abc386 Año: 2021 Publicado en: Nanotechnology 32, 6 (2021), 065703 [11 pp] ISSN: 0957-4484 Factor impacto JCR: 3.953 (2021) Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 161 / 345 = 0.467 (2021) - Q2 - T2 Categ. JCR: PHYSICS, APPLIED rank: 51 / 161 = 0.317 (2021) - Q2 - T1 Categ. JCR: NANOSCIENCE & NANOTECHNOLOGY rank: 64 / 109 = 0.587 (2021) - Q3 - T2 Factor impacto CITESCORE: 6.2 - Engineering (Q1) - Materials Science (Q1) - Chemical Engineering (Q2)