Facile control of morphological characteristics of magnetite aggregates (nFe(3)O(4)) by the addition of bifunctional ligands

Abstract

We demonstrated a facile method to control magnetite clusters with different size and surface morphology by adding bifunctional diamines. First, citrate-capped magnetites (C-Fe3O4) were prepared by adding citrate ions into ferrofluid during the coprecipitation process. The resulting C-Fe3O4 was subsequently treated by diamine molecules with different chain lengths (C-4, C-8, C-12), consequently leading to the formation of diamine-linked magnetite aggregates (D-nFe(3)O(4)) with different size and surface morphology. The longer chain length of diamines increased the particle size of D-nFe(3)O(4) due to the enhanced crosslinking between C-Fe3O4. The excessive addition of C-4 and C-12 diamines induced the significant morphological changes from irregular-shaped C-Fe3O4 to spherical and rod-shaped D-nFe(3)O(4), respectively. Furthermore, D-nFe(3)O(4) retained their initial magnetism under a strong oxidative process, implicating the potential application to recyclable catalyst or active electrode materials in Li-ion batteries. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim