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Published online 17 November 2014
Researchers have devised a new technique that allows the exchange of two different organic molecules (ligands) on the surface of silver molecular nanoparticles. This technique, described in the Journal of the American Chemical Society1, creates surface-modified silver nanoparticles that can be used to fabricate optoelectronic devices.
Chemical agents and solvents are usually used to make noble metal molecular nanoparticles. But these nanoparticles must be processed into smooth thin films to fabricate devices.
Researchers from King Abdullah University of Science and Technology (KAUST), Saudi Arabia and University of Mississippi, USA, have managed to modify molecular silver nanoparticles by synthesising them with surface-attached 5-mercapto-2-nitrobenzoic acid (MNBA) in water at ambient conditions.
They then substituted all the MNBA molecules attached to the surface of the nanoparticles with molecules of aryl thiol. Spectroscopic analyses revealed that the substitution process was complete in less than 30 seconds. When deposited on oxide surfaces, the aryl thiol-attached nanoparticles formed smooth thin films usable in device fabrication.
“The modified silver molecular nanoparticles are stable and can be stored for more than a year. These stored nanoparticles can undergo modifications through molecular exchange strategy whenever device fabrication is needed,” said Osman Bakr, a senior author of the study.