Journal: Nanoscale
Article Title: Esterification synthesis of iron oxide nanoparticle tracers for magnetic particle imaging (MPI)
doi: 10.1039/d5nr03157e
Figure Lengend Snippet: Low temperature esterification of Fe( ii ) oleate for synthesis of iron oxide nanoparticles at 290 °C and a precursor addition rate of 0.1 mmol min −1 yields particles that are too small to be effective MPI tracers. (A) Fourier Transform Infrared (FTIR) facilitates tracking of reaction progress, as the main peaks for the reagents (iron oleate and oleyl alcohol) and the ester product can be obtained from reaction aliquots. (B) Tracking FTIR intensity over reaction time demonstrates ester formation (yellow) and alcohol consumption (teal) in region (i) with the addition of 6 mmol of Fe. Further addition, results in iron oleate (brown) accumulation due to the alcohol depletion observed in region (ii). (C) Physical size distributions obtained from analysis of transmission electron microscopy (TEM) images show that polydisperse particles of ∼6 nm quickly form after 5 min of reaction and grow to a size of ∼10 nm after 120 min and 12 mmol Fe is added. Scale bars are 20 nm.
Article Snippet: Oleyl alcohol (80–85% technical grade), hexane (>98.5%, certified ACS), toluene (>99.5%, certified ACS), ethanol (200 proof), and tetrahydrofuran (THF, 99.8% for HPLC) were purchased from Thermo Fisher Scientific (Waltham, MA).
Techniques: Fourier Transform Infrared Spectroscopy, Transmission Assay, Electron Microscopy