Phase transfer and its applications in nanotechnology

Abstract

As nanoparticle syntheses in aqueous and organic systems have their own merits and drawbacks, specific applications may call for the transfer of newly formed nanoparticles from a polar to a non-polar environment (or vice versa) after synthesis. This critical review focuses on the application of phase transfer in nanoparticle synthesis, and features core-shell structures in bimetallic nanoparticles, replacement reactions in organic media, and catalytic properties of various nanostructures. It also describes the reversible organic and aqueous phase transfer of semiconductor and metallic nanoparticles for biological applications, and the use of phase transfer in depositing noble metals on semiconductor nanoparticles (258 references).

The supramolecular approach to the phase transfer of carboxylic calixresorcinarene-capped silver nanoparticles

“…At the other hand, the presence of oppositely charged ligand on the outer layer of nanoparticle's surfaces as well as the growth of it's concentration may lead not only to changes of hydrophobicity/philicity of metal nanoparticles surface but to the modification of their morphology and to produce ordered selfassemblies of metal nanoparticles [3,4,15].…”

“…There are some ways for modification of the hydrophobicity/philicity on metal nanoparticles surface such as ligand exchange, ligand chemical modification, or addition of layers of molecules that stabilize the particles in the desired phase [2,3]. The last one is used in the process of noncovalent modification of noble metals nanoparticle's surface as a result of the formation of ionic associates of nanoparticles ligands with opposite-charged organic molecules and surfactants [4][5][6][7][8][9].…”

“…The method of phase transfer represented an effective way for functionalizing metallic nanoparticles with suitable ligands towards the creation of close-packed, ordered arrays and nanoparticulate thin films. Also phase transfer has always been an important approach for the preparation of organosols of noble metals, since the methods for direct synthesis of noble metal nanoparticles in non-polar organic media were limited due to the poor solubility of the corresponding metal ion precursors [3].…”

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

“…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]. There are also reports presenting the ligands commonly used for surface modification in the phase transfer of metallic nanoparticles [13].…”

Spatial Analysis of Metal–PLGA Hybrid Microstructures Using 3D SERS Imaging

“…[26] However, anisotropic nanoparticles are often grown in water or other solvents with high dielectric constants, which may hinder their encapsulation in polymers. [27][28][29] We present here a universal method to embed metal nanoparticles of various composition, shape and size, in PLGA nanomaterials by means of the so-called electrohydrodynamic (EHD) co-jetting process. This process has been well established for PLGA over the last decade and offers a high throughput method to synthesize PLGA microgels of different sizes and morphologies.…”