Preparation Of Monodispersed Nickel Boride Catalysts Using Reversed Micellar Systems

Nagy, J.B.; Gourgue, A.; Derouane, Éric G.

doi:10.1016/s0167-2991(09)60021-5

Cited by 34 publications

(8 citation statements)

References 9 publications

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“…To take into account the influence of droplet size, we have introduced in the simulation a parameter q which restricts the maximum number of products P (and therefore the maximum particle size) which can be carried by a droplet. It should be noted that, as it was experimentally observed, ,− the final size of the particles may be slightly bigger or smaller than the droplet size, depending on the flexibility of the surfactant film and/or the surfactant adsorption. In this paper, we restrict our study to the case of very big droplet sizes ( q = 5000 units per droplet), so that this variable does not affect our results.…”

Section: Simulation Proceduresmentioning

confidence: 77%

Kinetics of the Formation of Particles in Microemulsions

et al. 1997

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In this paper the kinetics of the formation of nanoparticles in microemulsions is studied by Monte Carlo computer simulation. It is observed that compartmentalization of the reactants induces a separation of the nucleation and growth processes, which is more clearly observed when the concentration of reactants is relatively high. It is also observed that growth by autocatalysis and by ripening overlaps at low concentrations but occurs on different time scales at high concentration. A comparison between the results of these simulations and those from Smoluchowski's rapid-coagulation mechanism is made, showing that this theory is adequate to model the kinetics of these reactions.

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Section: Simulation Proceduresmentioning

confidence: 77%

Kinetics of the Formation of Particles in Microemulsions

et al. 1997

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“…The so-obtained nanoparticles are thermodynamically stabilized by the surfactants. Another model could explain the formation of monodisperse nanoparticles according to the LaMer diagram. , In this model, monodisperse nanoparticles can be formed if the nucleation is controlled, short, and separated from the growth phase. An experiment can be imagined which permits formation of a maximum of nuclei in a minimum of time and thus the nanoparticles obtained should have smaller sizes.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Organic Nanoparticles in Different W/O Microemulsions

et al. 2000

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Organic nanoparticles of cholesterol, Rhovanil, and Rhodiarome have been synthesized in different microemulsions (AOT/heptane/water; Triton/decanol/water; CTABr/hexanol/water) by direct precipitation of the active compound in aqueous core under continuous ultrasound treatment. Generally, the size of the nanoparticles depends on different parameters such as the concentration of the organic molecules and the diameter of the water cores which is related to the ratio R ) [H2O]/[surfactant]. The nanoparticles are observed by transmission electron microscope after a treatment with iodine vapor. The particles remain stable for months. The influence of the concentration of the organic molecules in the range between 50 and 400 g/L is studied. The average diameter of the nanoparticles does not vary much and is between 50 and 70 Å. The average size of the particles does not change much as a function of the ratio R (except in the case of cholesterol nanoparticles) or the concentration of the organic molecules. This can be explained by the thermodynamic stabilization of a preferential size of the particles. The reaction of precipitation has also been carried out using a magnetic stirrer. The size of nanoparticles is somewhat greater than that obtained by using a ultrasound bath. Different solvents are used to solubilize the organic molecules, but the average diameter of the particles does not change. The solvents are considered as a carrier vector for the organic molecules and do not influence the precipitation in a significant way.

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“…the maximum number of P units allowed in any single droplet. It should be noted that, as was experimentally observed, [26][27][28][29][30] the final size of the particles may be slightly bigger or smaller than the droplet size, depending on the flexibility of the surfactant film and/or the surfactant adsorption.…”

Section: Simulation Detailsmentioning

confidence: 97%

Preparation of Nanoparticles in Microemulsions: A Monte Carlo Study of the Influence of the Synthesis Variables

1997

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Monte Carlo simulations were performed to study the formation of nanoparticles in microemulsions. The influence of the following parameters on particle size distribution (PSD) was investigated: number of reagent molecules per droplet, surfactant film flexibility, droplet size, presence or absence of autocatalysis by the product, and the fraction of bulk volume made up by droplets. It was found that autocatalyzed reactions with high reagent concentrations and low surfactant film flexibility afforded bimodal PSDs. Particle size increased with reagent concentration when this was low, but at higher reagent concentrations it depended chiefly on droplet size. The dependence of PSD on reaction time confirmed the successive occurrence of well-defined nucleation and growth processes. We have compared the simulation results with experimental data taken from different authors and carried out in our laboratory. Good agreement between both kind of results supports the conclusions of this paper.

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Preparation Of Monodispersed Nickel Boride Catalysts Using Reversed Micellar Systems

Cited by 34 publications

References 9 publications

Kinetics of the Formation of Particles in Microemulsions

Kinetics of the Formation of Particles in Microemulsions

Synthesis of Organic Nanoparticles in Different W/O Microemulsions

Preparation of Nanoparticles in Microemulsions: A Monte Carlo Study of the Influence of the Synthesis Variables

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