Silica matrices for embedding of magnetic nanoparticles

Influence of polyols on the formation of nanocrystalline nickel ferrite inside silica matrices

“…In case of the composite obtained with 1,4-butanediol some structures appear, while in case of the composites NiFePVSi and NiFePVBDSi, the morphology of the silica matrix show spherical silica particles with diameters below 40 nm. Thus polyvinyl alcohol has a significant influence on what concern the formation of silica matrix [19].…”

“…Thus, for particles of 8.9 nm average size, they found = ⋅ K 1. 19 10 J/m eff 5 3 , which leads to 11.8 nm critical size (beyond which the particles will exhibit hysteresis). In addition, the contribution of the internal stresses (possibly of different extent for different synthesis reactions) are expected to lead to a further increase of K eff .…”

“…Nickel ferrite/silica nanocomposites have been obtained starting from different tetraethoxysilane without [16], or with modifiers as formamide [17], citric acid [11] and PVA [18]. Our previous studies have shown that polyols are efficient modifiers for the silica matrix, leading to obtaining homogenous magnetic ferrite/silica nanocomposites [19]. The polyols generate hybrid gels by chemical bonding of C-OH groups through condensation with the Si-OH groups from the siloxane network, affecting the final silica matrix structure and morphology [19].…”

“…Our previous studies have shown that polyols are efficient modifiers for the silica matrix, leading to obtaining homogenous magnetic ferrite/silica nanocomposites [19]. The polyols generate hybrid gels by chemical bonding of C-OH groups through condensation with the Si-OH groups from the siloxane network, affecting the final silica matrix structure and morphology [19]. Furthermore, due to their interaction with the metal nitrates, when M(II) and M(III) carboxylates form as precursors of ferrite nanoparticles, the polyols also have an influence on the formation of ferrite nanoparticles.…”

Synthesis of Magnetic Nanoparticles Incorporated Smart Gel

“…[14][15][16] Chemical crosslinking is a highly versatile method to modify PVA with improved mechanical, thermal and chemical stability. 17 PVA, with its good gel forming capability, is an ideal candidate for the synthesis of hybrid gels such as ferrogels and organic-inorganic hybrids. 18 A great number of methods have been developed for the immobilization of MNPs on supporting polymer materials.…”