Silica matrices for embedding of magnetic nanoparticles
- 242 Downloads
This paper presents a study regarding the formation of hybrid gels starting from tetraethyl orthosilicate (TEOS), polyvinyl alcohol (PVA) and 1,3-propanediol (PD) and their thermal evolution to mesoporous silica matrices. The possibility of obtaining homogenously dispersed cobalt ferrite inside the silica matrix starting from (TEOS–PVA–PD–Metal Nitrates) gels was also studied. The formation of the hybrid gels TEOS/PVA/PD with different compositions was studied by FT-IR spectrometry and thermal analysis, in order to evidence the interaction between the diol with the organic and the inorganic polymers. Both thermal analysis and FT-IR spectrometry have evidenced the formation of physical and chemical interaction between polyols and the siloxane network. Elemental mapping performed by SEM-EDX technique evidenced the formation of homogenous hybrids both in the presence of the absence of 1,3-propanediol. SEM images of the powders obtained by annealing the hybrid xerogels at 600 °C have evidenced the formation of mesoporous silica. By thermal treatment of the (TEOS–PVA–PD–Metal Nitrates) gels, 30%CoFe2O4/70%SiO2 (mass percent) nanocomposites uniformly dispersed in silica matrix with characteristic magnetic properties, have been successfully synthesized.
KeywordsHybrid gels PVA 1,3-propanediol Silica Cobalt ferrite Nanocomposite
This work was partially supported by the strategic grant POSDRU/21/1.5/G/13798 inside POSDRU Romania 2007–2013, co-financed by the European Social Fund—Investing in People and by the strategic grant POSDRU/88/1.5/S/50783, Project ID50783 (2009), co-financed by the European Social Fund—Investing in People, within the Sectoral Operational Programme Human Resources Development 2007–2013.
- 6.Pereira APV, Wasconcelos WL, Orefice RL (2000) Novel multicomponent silicate-poly(vinyl alcohol) hybrids with controlled reactivity. J Non-Cryst Solids 273:180–185Google Scholar
- 15.Brinker CJ, Scherer GW (1990) Sol-gel science-the physics and chemistry of sol-gel. Processing Academic Press, San DiegoGoogle Scholar
- 17.Ştefănescu M, Stoia M, Ştefănescu O, Davidescu C, Vlase G, Sfîrloagǎ P (2010) synthesis and characterization of poly(vinylalcohol)/ethylene glycol/silica hybrids. Thermal analysis and FT-IR study. Rev Roum Chim 55(1):17–23Google Scholar
- 20.Stoia M, Barvinschi P, Barbu Tudoran L, Barbu M, Stefanescu M (2012) Synthesis of nanocrystalline nickel ferrite by thermal decomposition of organic precursors. J Therm Anal Calorim. doi: 10.1007/s10973-011-1903-0
- 21.Joint Committee on Powder Diffraction Standards-International Center for Diffraction Data. Swarthmore, 1993Google Scholar