title: Ultrafast and continuous synthesis of crystalline ferrite nanoparticles in supercritical ethanol.
abstract: Magnetic nanoparticles (NPs) are of increasing interest in various industrially relevant products. For these, the development of greener and faster approaches facilitating scaling-up production is of paramount importance. Here, we report a novel, green and potentially scalable approach for the continuous and ultrafast (90 s) synthesis of superparamagnetic ferrite NPs (MnFe(2)O(4), Fe(3)O(4)) in supercritical ethanol (scEtOH) at a fairly moderate temperature (260 °C). ScEtOH exhibits numerous advantages such as its production from bio-resources, its lack of toxicity and its relatively low supercritical coordinates (p(c) = 6.39 MPa and T(c) = 243 °C), being therefore appropriate for the development of sustainable technologies. The present study is completed by the investigation of both in situ and ex situ NP surface functionalization. The as-obtained nanoparticles present good crystallinity, sizes below 8 nm, superparamagnetic behavior at room temperature and high saturation magnetization. Moreover, depending on the capping strategy, the ferrite NPs present extended (for in situ coated NPs) or short-term (for ex situ coated NPs) colloidal stability.
authors: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, E08193, Bellaterra, Spain.
authors: Oana
authors: O
authors: Pascu
authors: Samuel
authors: S
authors: Marre
authors: Cyril
authors: C
authors: Aymonier
authors: Anna
authors: A
authors: Roig
mesh_terms: D003460:Crystallization; D000431:Ethanol / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D013501:Surface-Active Agents; C001215:ferrite; D000431:Ethanol