Flow Synthesis of Iron Oxide Nanoparticles: Using Multiple Precursor Additions to Improve Size Control

Abstract

Controlling the size of iron oxide nanoparticles while maintaining uniformity in flow-based synthesis systems has been a great challenge in nanoparticle synthesis. Using an Extended LaMer mechanism, we improve both the size and shape uniformity as compared to a conventional flow synthesis. The key to this approach is the injection of additional Fe precursor during the flow reaction, providing extra precursor during the growth process leading to a size focusing step. This approach has also allowed for the systematic variation of the nanoparticle size produced in the flow reaction. These results represent a new synthetic concept for improving the size uniformity of iron oxide nanoparticles in flowbased synthesis and has potential for application across a wide range of nanoparticle systems.