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Rapid continuous microwave-assisted synthesis of silver nanoparticles to achieve very high productivity and full yield: from mechanistic study to optimal fabrication strategy.

Dzido G, Markowski P, Małachowska-Jutsz A, Prusik K, Jarzębski AB - J Nanopart Res (2015)

Bottom Line: Systematic studies of silver nanoparticle synthesis in a continuous-flow single-mode microwave reactor using polyol process were performed, revealing that the synthesis is exceptionally effective to give very small metal particles at full reaction yield and very high productivity.Owing to its much higher reactivity, silver acetate was shown to be far superior substrate for the synthesis of small (10-20 nm) spherical silver nanoparticles within a few seconds.The performed studies indicate an optimal strategy for the high-yield fabrication of metal particles using polyol method.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering and Process Design, Faculty of Chemistry, Silesian University of Technology, Ks. M. Strzody 7, 44-100 Gliwice, Poland.

ABSTRACT

Systematic studies of silver nanoparticle synthesis in a continuous-flow single-mode microwave reactor using polyol process were performed, revealing that the synthesis is exceptionally effective to give very small metal particles at full reaction yield and very high productivity. Inlet concentration of silver nitrate or silver acetate, applied as metal precursors, varied between 10 and 50 mM, and flow rates ranged from 0.635 to 2.5 dm(3)/h, to give 3-24 s reaction time. Owing to its much higher reactivity, silver acetate was shown to be far superior substrate for the synthesis of small (10-20 nm) spherical silver nanoparticles within a few seconds. Its restricted solubility in ethylene glycol, applied as the solvent and reducing agent, appeared to be vital for effective separation of the stage of particle growth from its nucleation to enable rapid synthesis of small particles in a highly loaded system. This was not possible to obtain using silver nitrate. All the observations could perfectly be explained by a classical LaMer-Dinegar model of NPs' formation, but taking into account also nonisothermal character of the continuous-flow process and acetate dissolution in the reaction system. The performed studies indicate an optimal strategy for the high-yield fabrication of metal particles using polyol method.

No MeSH data available.


Related in: MedlinePlus

EDX analysis for the silver NPs (T9)
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Fig3: EDX analysis for the silver NPs (T9)

Mentions: Preliminary experiments showed that for the continuous-flow synthesis of silver NPs in 3–24 s under continuous MW heating (thus nonisothermal conditions), the exit temperatures had to be held in the ranges of 150–180 °C and 90–175 °C, for silver nitrate and silver acetate, respectively. This allowed the region of the colloidal system formation to be kept within a microwave cavity, as could be checked from the silver ions’ content as determined by DPV measurements. In this way, we could conveniently control the process. EDX analysis of the colloidal mixture confirmed the abundant presence of silver particles, as deduced from the spectrum displayed in Fig. 3, where the C and Cu peaks come from the carbon-coated copper TEM grid. In addition, UV-absorption spectra of the colloidal systems, examined for the presence of surface plasmon resonance (SPR) bands of AgNPs at ~419 nm, corroborated silver NPs’ formation (Creighton and Eadon 1991; Mulvaney 1996). Selected samples were also examined using TEM and XRD. The obtained patterns appeared to exhibit pronounced peaks, which were found to correspond with crystallographic planes of face-centered cubic silver NPs. These patterns were also used to evaluate the size of crystalline particles from Scherrer equation. DLS analysis of the selected colloidal systems (T9, T14) after 1-month storage confirmed their quite good stability. Moreover, using the same procedure as applied for the preparation of TEM samples, we obtained solid samples, which could easily be redispersed in the liquid.Fig. 3


Rapid continuous microwave-assisted synthesis of silver nanoparticles to achieve very high productivity and full yield: from mechanistic study to optimal fabrication strategy.

Dzido G, Markowski P, Małachowska-Jutsz A, Prusik K, Jarzębski AB - J Nanopart Res (2015)

EDX analysis for the silver NPs (T9)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4300398&req=5

Fig3: EDX analysis for the silver NPs (T9)
Mentions: Preliminary experiments showed that for the continuous-flow synthesis of silver NPs in 3–24 s under continuous MW heating (thus nonisothermal conditions), the exit temperatures had to be held in the ranges of 150–180 °C and 90–175 °C, for silver nitrate and silver acetate, respectively. This allowed the region of the colloidal system formation to be kept within a microwave cavity, as could be checked from the silver ions’ content as determined by DPV measurements. In this way, we could conveniently control the process. EDX analysis of the colloidal mixture confirmed the abundant presence of silver particles, as deduced from the spectrum displayed in Fig. 3, where the C and Cu peaks come from the carbon-coated copper TEM grid. In addition, UV-absorption spectra of the colloidal systems, examined for the presence of surface plasmon resonance (SPR) bands of AgNPs at ~419 nm, corroborated silver NPs’ formation (Creighton and Eadon 1991; Mulvaney 1996). Selected samples were also examined using TEM and XRD. The obtained patterns appeared to exhibit pronounced peaks, which were found to correspond with crystallographic planes of face-centered cubic silver NPs. These patterns were also used to evaluate the size of crystalline particles from Scherrer equation. DLS analysis of the selected colloidal systems (T9, T14) after 1-month storage confirmed their quite good stability. Moreover, using the same procedure as applied for the preparation of TEM samples, we obtained solid samples, which could easily be redispersed in the liquid.Fig. 3

Bottom Line: Systematic studies of silver nanoparticle synthesis in a continuous-flow single-mode microwave reactor using polyol process were performed, revealing that the synthesis is exceptionally effective to give very small metal particles at full reaction yield and very high productivity.Owing to its much higher reactivity, silver acetate was shown to be far superior substrate for the synthesis of small (10-20 nm) spherical silver nanoparticles within a few seconds.The performed studies indicate an optimal strategy for the high-yield fabrication of metal particles using polyol method.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering and Process Design, Faculty of Chemistry, Silesian University of Technology, Ks. M. Strzody 7, 44-100 Gliwice, Poland.

ABSTRACT

Systematic studies of silver nanoparticle synthesis in a continuous-flow single-mode microwave reactor using polyol process were performed, revealing that the synthesis is exceptionally effective to give very small metal particles at full reaction yield and very high productivity. Inlet concentration of silver nitrate or silver acetate, applied as metal precursors, varied between 10 and 50 mM, and flow rates ranged from 0.635 to 2.5 dm(3)/h, to give 3-24 s reaction time. Owing to its much higher reactivity, silver acetate was shown to be far superior substrate for the synthesis of small (10-20 nm) spherical silver nanoparticles within a few seconds. Its restricted solubility in ethylene glycol, applied as the solvent and reducing agent, appeared to be vital for effective separation of the stage of particle growth from its nucleation to enable rapid synthesis of small particles in a highly loaded system. This was not possible to obtain using silver nitrate. All the observations could perfectly be explained by a classical LaMer-Dinegar model of NPs' formation, but taking into account also nonisothermal character of the continuous-flow process and acetate dissolution in the reaction system. The performed studies indicate an optimal strategy for the high-yield fabrication of metal particles using polyol method.

No MeSH data available.


Related in: MedlinePlus