The use of organic templates to develop biomimetic chain structures of magnetic nanoparticles

The double-tailed surfactants AOT (bis 2-ethylexyl sodium sulfosuccinate) and lecithin (phosphatidylcholine) self-assemble in the presence of water and a hydrocarbon to form fluid microstructures. The nanostructure of this gel appears to be made up of bicontinuous networked channels of water and the hydrocarbon phase, α-Fe nanoparticles are synthesized via reducing the ferrous salt in the aqueous microphase of the gel. Transmission electron microscopy of these particles reveals nanospheres with a uniform size distribution ranging from 15 to 18 nm in diameter. An interesting observation is that these nanoparticles appear to be synthesized in the form of entangled chains reminiscent of magnetic nanoparticles in magnetobacteria. Destruction of the gel phase still leaves the aggregation structure largely intact, implying a clear templating role of the surfactant microstructure. Magnetic properties of these particles were characterized using a SQUID susceptometer. The hysteresis loops at ambient temperature reveals a saturation magnetization of 190 emu/g and a coercivity of 240 G, indicating that the nanoparticles are ferromagnetic. The results indicate the possibility of nanoscale engineering of these materials with biomimeticproperties.