Stabilizers-Mediated Nanoparticles Syntheses

Abstract

Of the chemical processes, a reverse micelle (w/o microemulsion, a soft template) synthesis has been demonstrated to be a viable method for producing a wide array of noble metals over a relatively narrow particle size distribution. Noble metal colloids can be prepared in metal salt/(non)ionic surfactant/oil/water microemulsions by using both classical and nontraditional reductants. Reduction of metal ions occurred in microemulsions based on some ionic and nonionic surfactants without adding specific reductants. Mostly, the spherical metal nanoparticles are fabricated. A number of nonspherical nanomaterials of aligned noble metal colloids were found in the prolate ionic surfactants micelles. The citrate reduction method is well known for its simple procedure, yielding stable and reproducible gold nanoparticles of narrow size distribution. The coordination of metal ions with functional groups such as NH2 in polymer served as weak cross-linkers to attach polymer chains and formation and stabilization of metal colloids. Gold nanoparticles surrounding with silica shells as a support could be a potentially useful method for the preparation of highly active nanoconjugates assemblies. Laser ablation of solvent-suspended metal powders can be used in for synthesis of gold/silver alloy and core@shell nanoparticles of predetermined composition. The generation of polymer coatings for noble metal nanoparticles (NMNPs) may feature stimulus-responsiveness (pH, temperature, ionic strength, and light) and spontaneously form versatile supramolecular structures. Some of the physical and chemical properties of the core nanoparticles are often imparted to the resulting polymeric shell system, producing hybrid materials with novel properties and functions that are not possible from the single-component structure alone. Various reducing agents introduced into polymer-based micelle systems may result in the formation of NMNPs of various sizes. A new method of producing gold nanoparticles is a surfactant-free synthesis, high variability in the introduction of (functionalized) ligands, and good control over the particle size. Soft-ligand-stabilized nanoparticles can be used as precursors to obtain nanoparticles with different surface chemistry by replacing the soft ligands with other desired ligands. The ionic liquids stabilize the metal nanoparticles noncovalently via electrostatic interactions. They initiated the formation of various nanoparticles such as spherical, oblate, nanorods of different aspect ratios, and sharp-edged nanostructures. The versatility of the micellar nanostructure lies in its capacity to cargo drug molecules and biological macromolecules that are either hydrophilic, therefore entrapped in the liposome inner aqueous core, or hydrophobic, therefore incorporated within the lipid bilayer. PEO-modified noble metal nanomaterials have several attractive characteristics for diagnostic applications, including (1) biocompatibility and stability, (2) unique tunable optical properties, and (3) easy conjugation of biomolecules to the surface for tumor specific targeting.