Formation of Silver Chloride Nanoparticles in Microemulsions by Direct Precipitation with the Surfactant Counterion

Abstract

Nanoparticles of silver chloride were prepared by direct precipitation of silver ions with the surfactant counterion in the water pools of microemulsions formed by dioctyldimethylammonium chloride in an organic n-decanol/isooctane phase. This work represents a new concept to form nanoprecipitates using a single reverse micellar system. The net result is a fast reaction with less dependency on the intermicellar exchange of solubilizate. The effects of the surfactant and cosurfactant concentrations, of the mole ratio of water to surfactant, R, and of the loading of silver nitrate were evaluated. Increasing the surfactant concentration at fixed values of R and moles of silver nitrate resulted in a higher dependency on the reverse micellar exchange dynamics and increased the particle size. At high n-decanol concentration, the particle size increased due to decreasing the interaction between the nanoparticles and the stabilizing surfactant layer. Similar results were found at high values of R. Increasing the amount of silver nitrate resulted in the formation of more nuclei, and hence in the production of smaller particles. The trends in the particle size and the size distribution were followed using UV spectrophotometry and transmission electron microscope photographs.

Regulations of silver halide nanostructure and composites on photocatalysis

“…So far, quantities of nanoparticles with variable architectures have been successfully fabricated including nanorods [189][190][191], nanocubes [192], nanowires [193,194], nanoplates [195][196][197], and feather or dendrite-like crystal structures [198]. Initially, micelle-based synthesis is capable of preparing AgX nanoparticles through mixing two identical reverse micelles each containing silver ions or halide ions [188,[199][200][201][202][203][204]. Two kinds of reverse micelles after mixing rapidly repeat collide with association and dissociation processes companying reaction ions exchanges.…”

“…In these reverse micelles reaction for AgX, the surfactant molecules have a strong effect on the morphologies of AgX nanostructures through acting as soft templates as well as affecting reaction parameters, such as precursor ions reaction trace and reaction rate [199]. In addition, taking advantage of Br − and Cl − that existed in molecules of cetyltrimethylammonium (CTAB) and cetyltrimethylammonium chloride (CTAC), AgBr and AgCl can be facilely fabricated without addition of external X − resource [147,202,[205][206][207]. Liu group used an oil-in-water mixture microemulsion of CTAC chloroform solution and AgNO 3 aqueous solution to one-pot synthesize two (Fig.…”

Metal‐halide Nanoparticle Formation: Electrolytic and Chemical Synthesis of Mercury(I) Chloride Nanoparticles

“…[7][8][9] Other methods include the controlled precipitation of metal halides in aqueous media, for example, AgBr NP suspensions stabilised in solution by materials such as gelatine [10] and cucurbit[n]uril macrocycles. [11] Although the area has seen significant development, there are few examples for the formation of particles of sizes 20-100 nm without complex multi-step chemical processes and stabilising organic coatings.…”

Formation of silver bromide precipitate of nanoparticles in a single microemulsion utilizing the surfactant counterion

“…Using this technique, for rapid reactions nucleation is controlled by the intermicellar exchange of solubilizate, which is governed by the opening of the surfactant layer [13][14][15][16]. In a previous work [17], we studied the formation of AgCl nanoparticles in a single-microemulsion system by reaction of Ag + with the dioctyldimethylammonium chloride surfactant counterion Cl − . The source of Ag + was an aqueous solution of AgNO 3 added to the microemulsion.…”