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Ionic bis-nanoparticle networks.

Neouze MA, Litschauer M, Puchberger M, Bernardi J - Monatsh. Chem. (2012)

Bottom Line: Although some nanoparticle networks have been reported, few works are addressing the highly exciting problem of forming bis-nanoparticle assemblies in which two different types of nanoparticles are present.In this article we report an original synthesis pathway for the formation of an ionic bis-nanoparticle network, silica/silver, based on the formation of an imidazolium bridging unit.This composite formation is therefore very general and could be extended to other metal/metal oxide composites. .

View Article: PubMed Central - PubMed

Affiliation: Institute of Materials Chemistry, Vienna University of Technology, Vienna, Austria.

ABSTRACT

Abstract: A newly arising challenge in the field of nanoparticle research concerns the control and the understanding of the interparticle interactions and interparticle properties. This should allow the development of materials based on nanoparticle assemblies which represents a great opportunity to exploit nanoparticle collective properties. Although some nanoparticle networks have been reported, few works are addressing the highly exciting problem of forming bis-nanoparticle assemblies in which two different types of nanoparticles are present. In this article we report an original synthesis pathway for the formation of an ionic bis-nanoparticle network, silica/silver, based on the formation of an imidazolium bridging unit. The reaction used for the formation of the bridging imidazolium can be considered as click-like chemistry. The synthesis of the metal/metal oxide hybrid composite material starts from the formation of a metal oxide nanoparticle modified with an imidazole ligand. This composite formation is therefore very general and could be extended to other metal/metal oxide composites.

Graphical abstract: .

No MeSH data available.


Top1H NMR spectra of, from top to bottom, N-methylimidazole, mercaptopropionic acid and thio-imidazolium carboxylate. Bottom reaction scheme
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Fig1: Top1H NMR spectra of, from top to bottom, N-methylimidazole, mercaptopropionic acid and thio-imidazolium carboxylate. Bottom reaction scheme

Mentions: The imidazole functional group on the surface of the nanoparticle is then modified to introduce thiol functional groups, which are preferential grafting functionalities for the coordination to metal surfaces [16]. This modification is aided by the basicity of the imidazole groups. On addition of mercaptopropionic acid to the imidazole-functionalized nanoparticle suspension, the acidic protons of the carboxylic acid group will be transferred to the nitrogen of the imidazole unit. This reaction, in the liquid state, so without nanoparticles, can be followed by 1H NMR. In the NMR spectrum (Fig. 1, top), the formation of the imidazolium unit is characterized by a 1 ppm shift toward lower field of the aromatic protons. In addition, the carboxylic acid proton of the precursor, around 12 ppm, can no longer be observed, whereas a strongly broadened peak in the same region can be identified, characteristic of a labile, exchangeable proton, as is reported for such imidazolium carboxylate units [17].Fig. 1


Ionic bis-nanoparticle networks.

Neouze MA, Litschauer M, Puchberger M, Bernardi J - Monatsh. Chem. (2012)

Top1H NMR spectra of, from top to bottom, N-methylimidazole, mercaptopropionic acid and thio-imidazolium carboxylate. Bottom reaction scheme
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4495052&req=5

Fig1: Top1H NMR spectra of, from top to bottom, N-methylimidazole, mercaptopropionic acid and thio-imidazolium carboxylate. Bottom reaction scheme
Mentions: The imidazole functional group on the surface of the nanoparticle is then modified to introduce thiol functional groups, which are preferential grafting functionalities for the coordination to metal surfaces [16]. This modification is aided by the basicity of the imidazole groups. On addition of mercaptopropionic acid to the imidazole-functionalized nanoparticle suspension, the acidic protons of the carboxylic acid group will be transferred to the nitrogen of the imidazole unit. This reaction, in the liquid state, so without nanoparticles, can be followed by 1H NMR. In the NMR spectrum (Fig. 1, top), the formation of the imidazolium unit is characterized by a 1 ppm shift toward lower field of the aromatic protons. In addition, the carboxylic acid proton of the precursor, around 12 ppm, can no longer be observed, whereas a strongly broadened peak in the same region can be identified, characteristic of a labile, exchangeable proton, as is reported for such imidazolium carboxylate units [17].Fig. 1

Bottom Line: Although some nanoparticle networks have been reported, few works are addressing the highly exciting problem of forming bis-nanoparticle assemblies in which two different types of nanoparticles are present.In this article we report an original synthesis pathway for the formation of an ionic bis-nanoparticle network, silica/silver, based on the formation of an imidazolium bridging unit.This composite formation is therefore very general and could be extended to other metal/metal oxide composites. .

View Article: PubMed Central - PubMed

Affiliation: Institute of Materials Chemistry, Vienna University of Technology, Vienna, Austria.

ABSTRACT

Abstract: A newly arising challenge in the field of nanoparticle research concerns the control and the understanding of the interparticle interactions and interparticle properties. This should allow the development of materials based on nanoparticle assemblies which represents a great opportunity to exploit nanoparticle collective properties. Although some nanoparticle networks have been reported, few works are addressing the highly exciting problem of forming bis-nanoparticle assemblies in which two different types of nanoparticles are present. In this article we report an original synthesis pathway for the formation of an ionic bis-nanoparticle network, silica/silver, based on the formation of an imidazolium bridging unit. The reaction used for the formation of the bridging imidazolium can be considered as click-like chemistry. The synthesis of the metal/metal oxide hybrid composite material starts from the formation of a metal oxide nanoparticle modified with an imidazole ligand. This composite formation is therefore very general and could be extended to other metal/metal oxide composites.

Graphical abstract: .

No MeSH data available.