Ultrafast and continuous synthesis of crystalline ferrite nanoparticles in supercritical ethanol

Oana Pascu (1) , Samuel Marre (2) , Cyril Aymonier (2) , Anna Roig (1)

1 ICMAB - Institut de Ciència de Materials de Barcelona
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

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.

Mots clés: Supercritical fluids; Ethanol; Nanoparticles; Ferrites

Domaines: Matériaux

Oana Pascu, Samuel Marre, Cyril Aymonier, Anna Roig. Ultrafast and continuous synthesis of crystalline ferrite nanoparticles in supercritical ethanol. Nanoscale, 2013, 5 (5), pp.2126-2132. ⟨10.1039/c3nr33501a⟩. ⟨hal-00789786⟩