Abstract
Gold nanoparticles are commonly manufactured by the citrate reduction method, a synthesis method pioneered by Turkevich et al. (1951). Based on their experimental evidence, Turkevich et al. (1951) advanced the organizer theory, a nucleation-growth synthesis mechanism. Subsequently, Kumar et al. (2007) developed a mathematical model for the description of the synthesis, basing it on such a theory. However, this model has not been thoroughly tested. Recently, contrary to the evidence provided by Turkevich et al. (1951), other mechanistic descriptions of the synthesis, which emphasize the role of the pH of the solution, have been advanced in the literature. In this paper, we investigated the model of Kumar et al. (2007) for different conditions of pH, temperature and initial reactant concentrations. To solve the model, we used the numerical code Parsival, which is used for solving population balance equations. We tested the model for different synthesis conditions studied experimentally by various researchers, for which results are available in the literature. The model poorly predicted the experimental data because the Turkevich organizer theory does not account for the acid-base properties of chloroauric acid and sodium citrate. A new model, with a more accurate mechanistic description of the synthesis and of the chemistry involved, is therefore required.
Highlights
Research in nanotechnology is increasing and is prioritized in developed countries such as the United States, the United Kingdom and Japan
We focus on metal and, in particular, gold nanoparticles
We briefly review the mathematical model developed by Kumar et al (2007) for the Gold nanoparticles (GNPs) synthesis by the citrate method
Summary
Research in nanotechnology is increasing and is prioritized in developed countries such as the United States, the United Kingdom and Japan. When performing the synthesis at 75 0C, for initial pH values of the precursor between 3 and 5, Wuithschick et al (2015) reported that nuclei aggregate until forming particles of stable size, which they called seeds Thereafter, these grow into the final GNPs. Thereafter, these grow into the final GNPs This description is referred to as “seed-mediated” mechanism. In a recent publication, Kettemann et al (2016) discussed the importance of the speciation of the precursor and reducing agent at different pH This aspect of the synthesis is not accounted for in the theory of Turkevich et al (1951) and, in the model developed by Kumar et al (2007). We consider factors such as the initial concentrations of the precursor and reducing agent, the initial and final pH of the reaction solution, and the temperature of the latter
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
