Synthesis of NaX (X = F, Cl, Br, I) Nanoparticles

Abstract

We report here on the synthesis of nanoparticles (NPs) of sodium halide (NaX; X = F, Cl, Br, I) salts using reverse micelles (water/dioctylsodiumsulfosuccinate/toluene) with the resulting NPs having diameters of 1.5 to 2.5 nm. The initial core of reverse micelle contains a water-soluble salt. After evaporation of the volatile compounds under vacuum (water and toluene), NaX NPs are produced with an AOT surfactant cap. The NaX NPs redisperse in toluene. In contrast to previous syntheses of soluble salt NPs, Na + ions from the surfactant are found to completely exchange with the salt in the initial core of the reverse micelles. The resulting NPs were analyzed with dynamic light scattering (DLS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) which confirmed the exchange mechanism. Experimental results are compared and found to be in agreement with the recently published model by Bandopadhyaya and coworkers.

Composition and Size of Reverse Micelles of Tergitol NP-4 and Tergitol NP-4 + AOT inN-Decane during Evaporation Crystallization of KNO3

“…Total lack of crystallization at evaporation of water from AOT microemulsions agrees with the observations of the author of the procedure for producing “free” nanoparticles of water-soluble salts. − Nanoparticles (or rather a composite consisting of nanoparticles in the matrix of “dry” AOT) were produced under total evaporation of water and volatile solvent (hexane or toluene). However, this procedure cannot be attributed to a microemulsion procedure because, as it was fairly mentioned in ref , during the evaporation of solvent, a microemulsion system passes into a liquid-crystal form.…”

Cs Adsorption and CsCl Particle Formation Facilitated by Amino Talc-like Clay in Aqueous Solutions at Room Temperature

“…The exfoliated basal spacing of LAC@1 may trap Cs + and Cl − ions leading to supersaturation, allowing the nucleation and formation of CsCl particles, especially during the drying process. 26,32 Additionally, Figure S4 shows the Cs uptake by LACs, Mmt, and talc at different contact time intervals. It shows that the Cs uptake by Mmt and talc has reached the maximum Cs uptake at 10 min contact time, while LAC@1 and LAC@2 show longer time to reach the maximum Cs uptake.…”

“…The presence of more −NH 2 was expected to create a large number of hydrogen bonds between the two −NH 2 for LAC@2 than LAC@1 that may prevent the basal spacing exfoliation. The exfoliated basal spacing of LAC@1 may trap Cs + and Cl – ions leading to supersaturation, allowing the nucleation and formation of CsCl particles, especially during the drying process. , …”

Colloidal Synthesis of CsX Nanocrystals (X = Cl, Br, I)

“…Among the successful methods that have been applied in the synthesis of alkali halides are high temperature vapor–liquid–solid techniques, enabling the production of either nanowires [ 16 ] or nanoparticles [ 12 ], a water-based reverse micellar synthetic method [ 17 ] and electrospray techniques [ 18 ]. However, none of these methods have shown the versatility usually provided by colloidal nanocrystal synthesis in organic solutions.…”