The chemistry behind the sol–gel synthesis of complex oxide nanoparticles for bio-imaging applications

Alkoxide-based precursors for direct drawing of metal oxide micro- and nanofibres

“…118 Sn, 13 C and 2 H NMR spectra were recorded with a Bruker AMX 500 FT NMR instrument using CDCl 3 as the solvent and tetramethyl tin as the external standard. 4 .…”

“…This property is explained by the extremely high acidity of metal alkoxides in the Lewis sense, that is the driving force of self-agglomeration [12,13]. Abnormal behaviour of these alkoxides was noticed by Bradly who during the 1950 s proved, using cryoscopic and ebullioscopic molar mass detection methods, that these compounds exist as trimers or tetramers rather than monomers [39].…”

“…Metal oxo-alkoxides are known to consist of nanospheres [12,13,42], and thus the elongated shape can be explained by the formation of secondary particles. Such behaviour of metal alkoxides is well known and could finally lead to the formation of a 3D solid network and 4 .…”

“…R = 0.7 is the mole ratio of the AQ-treated Sn(OBu) 4 sample. gelation [12,13]. NAQ fraction 3 contained clusters up to 2 nm in length.…”

“…It considers metal alkoxides as Lewis acids that undergo one-step polycondensation as soon as water is added. Well-defined oligonuclear oxo-alkoxide species form in this process [13]. Non-aqueous (NAQ) condensation-the Bradly's reaction-proceeds by ether elimination at elevated temperatures [14,15].…”