Magnetic hydrophobicnanocomposites:Silicaaerogel/maghemite

P. MENDOZA ZÉLIS, M.B.FERNÁNDEZ VANRAAP, L.M.SOCOLOVSKY, A.G.LEYVA, F. H. SÁNCHEZ

PHYSICA B - CONDENSED MATTER

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 407 p. 3113 - 3116

0921-4526

Magnetic hydrophobic aerogels (MHA) in the form of nanocomposites of silica and maghemite (gamma-Fe2O3) were prepared by one step sol–gel procedure followed by supercritical solvent extraction. Silica alcogels were obtained from TEOS, MTMS, methanol and H2O, and Fe(III) nitrate as magnetic precursor. The hydrophobic property was achieved using the methytrimethoxysilane (MTMS) as co- precursor for surface modification. The so produced nanocomposite aerogels are monolithic, hydrophobic and magnetic. The interconnected porous structure hosts 6 nm size gamma-Fe2O3 particles, has a mean pore diameter of 5 nm, and a specific surface area (SSA) of 698 m2/g. Medium range structure of MHA is determinedbySAXS,whichdisplaysthetypicalfractalpowerlawbehaviorwithprimaryparticle radiusof 1 nm.Magneticpropertiesofthenanoparticleensembleshostedinthemarestudiedbymeansofdc-magnetometry.