Phase transfer protocols in nanoparticle synthesis

Development of synthesis protocols for realizing nanomaterials over a range of sizes, shapes and chemical compositions is an important aspect of nanotechnology. A number of recipes have been developed for the synthesis of metal nanoparticles in polar (for example, water) and non-polar organic solvents, each method accompanied by characteristic advantages and disadvantages. Specific applications often require the transfer of already formed nanoparticles from a polar to non-polar environment (and vice versa), thereby maximizing the advantages of both methods. In this article, I discuss how such nanoparticle phase transfers may be accomplished through imaginative use of capping molecules that modify the hydrophilicity/ hydophobicity of the nanoparticle surface.