https://zenodo.org/record/1000724/files/article.pdf

An evidence-based environmental perspective of manufactured silver nanoparticle in syntheses and applications: a systematic review and critical appraisal of peer-reviewed scientific papers.

Stable colloidal suspension of magnetic nanoparticles is challenging owing to both van der Waals forces and magnetic dipolar interactions. Thus, it is essential to coat magnetic nanoparticles with ...

Interaction of Fatty Acid Monolayers with Cobalt Nanoparticles

This paper describes a simple and convenient procedure based on the Tollens process for the preparation of silver nanoparticles with a relatively narrow distribution in size. The starting reagents were similar to those commonly used in the electroless deposition of silver. Only under appropriate conditions, mixing of these reagents was able to generate stable aqueous dispersions of silver colloids rather than thin films of silver deposited on the surfaces of objects immersed in the plating solution (including the interior surface of the container). We have demonstrated the capability and feasibility of this approach by forming silver nanoparticles with dimensions in the range of 20–50 nm. These silver nanoparticles could exist as very stable dispersions in water, or as submonolayer coating on microscale colloids. We have also explored the use of light scattering simulation to study the oxidation (by air) of these nanoparticles.

Synthesis and characterization of stable aqueous dispersions of silver nanoparticles through the Tollens process

▪ Abstract This review focuses on the preparation of capped nanoparticles of inorganic materials, classified by composition. The materials described include elemental metals and metalloids (semiconductors), chalcogenide II–VI and IV–VI semiconductors, III–V semiconductors, and oxides (both of simple- and multitransition metal). Although particular emphasis is placed on methods that yield large volumes of nanoparticles, recent novel methods that may not necessarily be scalable are also reviewed. The review makes apparent the richness of chemistry that has become routine to practitioners in the field; diverse inorganic systems with distinct chemistry require distinct methods of preparation.

Synthesis routes for large volumes of nanoparticles

We demonstrate that the amino acid tyrosine is an excellent reducing agent under alkaline conditions and may be used to reduce Ag+ ions to synthesize stable silver nanoparticles in water. The tyrosine-reduced silver nanoparticles may be separated out as a powder that is readily redispersible in water. The silver ion reduction at high pH occurs due to ionization of the phenolic group in tyrosine that is then capable of reducing Ag+ ions and is in turn converted to a semi-quinone structure. These silver nanoparticles can easily be transferred to chloroform containing the cationic surfactant octadecylamine by an electrostatic complexation process. The now hydrophobic silver nanoparticles may be spread on the surface of water and assembled into highly ordered, linear superstructures that could be transferred as multilayers onto suitable supports by the versatile Langmuir-Blodgett technique. Further, tyrosine molecules bound to the surface of Au nanoparticles through amine groups in the amino acid may be used to selectively reduce silver ions at high pH on the surface of the Au nanoparticles, thus leading to a simple strategy for realizing phase-pure Au core-Ag shell nanostructures.

Synthesis of aqueous Au core-Ag shell nanoparticles using tyrosine as a pH-dependent reducing agent and assembling phase-transferred silver nanoparticles at the air-water interface.

We study the preparation and capping of silver nanoparticles by several unsaturated long-chain carboxylates UV−visible and FTIR spectroscopy and high-resolution electron microscopy are used to characterize the effect of the chain length, its configuration, and the degree of unsaturation on the size distribution of the nanoparticles Langmuir layers and Langmuir−Blodgett films are used to study the adsorption of these carboxylates on the particles We find that unsaturated carboxylates in the cis configuration are useful stabilizers for the control of particle size and its surface properties

Silver Nanoparticles Capped by Long-Chain Unsaturated Carboxylates

We study the in situ fabrication of copper sulfide nanoparticles within a three-dimensional (3D) organic-layered solid crystal of alkylammonium−metal complexes by their reaction with H2S gas. UV−vis spectroscopy and high-resolution electron microscopy are used to monitor the formation of the nanoparticles and to characterize them. The overall two-dimensional-layered structure of the alkylammonium is preserved during the reaction as seen by FTIR, though deformations near the particles are expected. The reaction kinetics for different chain lengths and metal ions (Cu, Mn, and Cd) have been measured and discussed in terms of the rigidity of the layered 3D structures.

Xiao Chen

Papers

Silver Nanoparticles Capped by Long-Chain Unsaturated Carboxylates

Fabrication of Semiconductor Nanoparticles in a Three-Dimensional Organic-Layered Solid Crystal