Nanosized Particles Made in Colloidal Assemblies

Abstract

In this feature article, syntheses of nanosized particles by using colloidal assemblies as a template are described. We asked ourselves the following question: What parameters play a role in the control of the size, shape, and polydispersity? We know that parameters such as the shape of colloidal assemblies, the hydration of the head polar group, the water molecules bounded to the interface, etc. play a major role. However, there are a number of exceptions preventing any generalization. It is shown that the chemical mechanism in nanoparticles production in colloidal assemblies can differ from those usually observed in homogeneous solution. This shows that the solution chemistry cannot always be transferred to colloidal systems. It is possible to select the size and markedly reduce the polydispersity by a surface treatment of the nanoparticles. This favors formation of mono-and multilayers made of nanoparticles, and it is found that these particles form crystals organized in a three-dimensional face-centered cubic superlattice.

Block copolymer-mediated synthesis of silver nanoparticles from silver ions in aqueous media

“…Alcohols are very often used as reducing agents for the synthesis of metal nanoparticles [1,3,19]. However, in our experiments, the reduction of Ag + ions and Ag nanoparticle formation are not observed in aqueous solutions containing alcohols (e.g., methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol and glycerol) at concentrations that are consistent with the PEO-PPO block copolymer concentration range used in our work.…”

“…(a) Alcohol (hydroxyl) functionality of a PEO-PPO block copolymer molecule for metal ion reduction [1,3].…”

Hydrogen-assisted fabrication of spherical gold nanoparticles through sonochemical reduction of tetrachloride gold(III) ions in water

“…Methodology to selectively synthesize metal nanoparticles with a particular size and shape enables rational control the properties of metal nanoparticles. Thus, a number of works have focused on the development of synthetic methods for the preparation of metal nanoparticles in a size or shape-selected and -controlled manner [13][14][15][16][17][18][19][20][21][22][23][24]. In addition, the synthetic strategy of metal nanoparticles in view of environmental concerns (e.g., utilization of non-toxic chemicals, environmentally benign solvents, and renewable materials) is emerging an issue that merit important consideration [25,26].…”

“…Conventional methods of metal nanoparticle synthesis from metal ion reduction in solutions require capping agents (e.g., alkylthiols, surfactants and amphiphilic polymers) and reducing agents (e.g., NaBH4, hydrazine and citric acid) to achieve the controlled synthesis of metal nanoparticles [13][14][15][16][17][18][19][20][21][22][23][24]. Numerous reports have described the size-and shape-control of metal nanoparticles in terms of molecular characteristics of capping agents and kinetics of metal ion reduction by reducing agents [13][14][15][16][17][18][19][20][21][22][23][24].…”

“…Numerous reports have described the size-and shape-control of metal nanoparticles in terms of molecular characteristics of capping agents and kinetics of metal ion reduction by reducing agents [13][14][15][16][17][18][19][20][21][22][23][24]. On the other hand, we have recently investigated the synthesis of gold nanoparticles (AuNPs) through the sonochemical reduction of tetrachloride gold(III) ions ([AuCl4] -) in aqueous solutions in the absence of any additional reducing and capping agents [27].…”