Aqueous−Organic Phase Transfer of Gold Nanoparticles and Gold Nanorods Using an Ionic Liquid

Abstract

The water-immiscible ionic liquid, [C4MIM][PF6], is a solvent medium that allows complete transfer of gold nanoparticles from an aqueous phase into an organic phase. Both spherical and rod-shaped gold nanoparticles are efficiently transferred from an aqueous solution into the organic phase without requiring the use of thiols. The sizes and shapes of the gold nanoparticles were preserved during the phase-transfer process when a surfactant was added to the ionic liquid. This process offers a simple approach for obtaining solutions of differently sized and shaped gold nanoparticles in ionic liquids.

Ionic Liquids as Designer Solvents for the Synthesis of Metal Nanoparticles

“…However, sometimes additional stabilizing agents are required for metal nanoparticles stabilization in IL, which provide additional flexibility for the phase transfer of metal nanoparticles to different solvent media. Stabilizing agents such as citrate (Wei et al, 2004), oleic acid (Wang & Yang, 2006), dendrimers (Ou et al, 2008), phenanthroline (Huang et al, 2003), bipyridine (Leger et al, 2008), poly(vinylpyrrolidone) (Yang et al, 2008), and IL-like polymers have been used during metal nanoparticles synthesis in ILs. Despite these studies, it is still not encouragingly clear how ILs and additional stabilizing agents interact with metal nanoparticles surface.…”

Ionic liquids in sample preparation

“…Wei et al [98,99] . The authors attributed this extraction to a cation-exchange process at the water-IL interface, and they estimated that the distribution ratio is larger than 10 4 .…”

Aqueous-Organic Phase Transfer of Gold and Silver Nanoparticles Using Thiol-Modified Oleic Acid

“…Each environment presents its unique advantages and disadvantages [5][6][7]. Nevertheless, in general, the synthesis of metallic nanoparticles in organic solvents is very sensitive and thus requires considerable effort to develop convenient size-and shape-controllable processes, while the synthesis of those in aqueous solutions has many well-defined preparation procedures [8]. In many cases, the transfer of gold nanoparticles between polar and non-polar environments is necessary to increase the applications of the particles, as well as to obtain advantages of the manufacturing process.…”

“…In many cases, the transfer of gold nanoparticles between polar and non-polar environments is necessary to increase the applications of the particles, as well as to obtain advantages of the manufacturing process. The phase transfer of gold nanoparticles from polar to non-polar solvents has been studied using ionic liquids [8], phenolic hydroxyl groups [9], thiol ligands [10,11], etc. There are various reports that present many particular methodologies that have been established for the metallic nanoparticles phase transfer from an aqueous phase to an organic medium or vice versa [12].…”