Analysis of iron(iii) doped silica nanorods synthesized with various iron reagents and TEOS ratios

Abstract

Silica nanorods integrated into materials, such as polymer matrices, may result in new or improved material properties. Desirable properties, like mechanical strength or thermal and electrical conductivity, can be enhanced by uniformly aligning nanorods. Magnetic fields are a promising and non-destructive way to orient nanorods embedded in a system, but silica itself has low magnetic susceptibility. This work investigates multiple reagents to synthesize iron-doped silica nanorods to increase the magnetic rearrangement of otherwise diamagnetic silica nanorods. A variety of nanorods are synthesized using different ratios of tetraethyl orthosilicate (TEOS) and iron-containing reagents. These nanorods are analyzed with scanning electron microscopy (SEM) and x-ray diffractometry (XRD). When compared to a control spectra of magnetite nanoparticles, some of the nanorods exhibit peaks characteristic of magnetite. However, SEM images indicate an amalgamation of rod shapes and irregular clumps. Samples synthesized with iron(iii) ethoxide and lower TEOS ratios demonstrate the most promise of compositional homogeneity and iron incorporation. Future work should harness analysis techniques that can provide compositional data of specific regions, such as backscattered electron imaging (BEI) or energy dispersive x-ray spectroscopy (EDX/EDS).