Synthesis and characterization of DL-thioctic acid (DLTA)-Fe3O4 nanocomposite

DL-Thioctic acid (DLTA) coated magnetite (Fe3O4) NP's have been prepared by the co-precipitation of iron oxide in the presence of DLTA. The product identified as magnetite, which has an average crystallite size of 7 +/- 2 nm as estimated from X-ray line profile fitting. Particle size was estimated as 11 +/- 1 nm from TEM micrographs. FT-IR analysis showed that the binding of DLTA on the surface of iron oxide is through carboxyl group is bidentate. VSM analysis explained the super-paramagnetic nature of the nanocomposite. TG analysis showed that the 80% of the nanocomposite was DLTA and 10% was Fe3O4, respectively. The conductivity measurements displayed the magnetic transition at similar to 60 degrees C for DLTA-Fe3O4 NPs. Analysis of the conductivities reveals the fact that the a. c. conductivity shows a frequency-dependent behavior while d.c. electrical conductivity is strongly temperature dependent and is classified into two regions over a limited temperature range of up to 120 degrees C. Toxicity was tested measured by LDH assay. (C) 2011 Elsevier B. V. All rights reserved.