Synthesis and analysis of surfactant-capped iron oxide nanoparticles.

摘要

The formation of iron oxide nanoparticles synthesized by thermal decomposition of iron(III) acetylacetonate in the presence of organic reducing surfactants is investigated. The surface composition and surface properties are studied through the use of FT-IR, differential scanning calorimetry, thermogravimetric analysis, and x-ray diffraction. Oleylamine was found to be the most reliable surfactant, and intermediate concentrations of oleylamine and iron precursor produced the highest quality monodisperse particles. Higher temperature generally lead to larger monodisperse particles. UV-vis spectra have shown that during particle growth, amine surfactants likely form a stabilizing monomer complex likely through the formation of an iron-nitrogen bond. When using oleylamine as a surfactant the surface density of molecules was calculated at approximately 1.2 ± 0.5 molecules per square nanometer. Alcohol and amine surfactants were found to show higher affinity to the particle surface than organic acid. Langmuir-Blodgett monolayers were fabricated out of iron oxide particles and were found to be more stable when made from dilute solutions and compressed at slow speed.