title: Seed-Mediated Hot-Injection Synthesis of Tiny Ag Nanocrystals on Nanoscale Solid Supports and Reaction Mechanism.
abstract: Controlling the size and shape of noble Ag nanocrystals (NCs) is of great interest because of their unique size- and shape-dependent properties, especially below 20 nm, and because of interesting applications in drug delivery, sensing, and catalysis. However, the high surface energy and tendency of these tiny NCs to aggregate deteriorates their unique properties and limits their applications. To avoid the aggregation of Ag NCs and improve their performance, we report a seed-mediated hot injection approach to synthesize highly dispersed tiny Ag NCs on a nanosized solid CaCO3 support. This simple, low-cost, and effective chemical approach allows for synthesizing highly uniform Ag NCs (∼10 nm) on the surface of presynthesized CaCO3 single NCs (∼52 nm) without any aggregation of the Ag NCs. Viscose fibers were coated with the Ag@CaCO3 composite nanoparticles (NPs) produced, as well as with ∼126 nm Ag NPs for reference. The Ag@CaCO3 composite NPs show excellent UV protection and antibacterial activity against Escherichia coli. In addition, they give a satin sheen gold to a dark gold color to the viscose fibers, while the Ag NPs (∼126 nm) result in a silver color. The proposed synthesis approach is highly versatile and applicable for many other noble metals, like Au or Pt.
authors.affiliation: Physical Chemistry and Polymer Science, Department of Materials and Chemistry, Vrije Universiteit Brussels , Pleinlaan 2, 1050 Brussels, Belgium.|Chemistry Department, Faculty of Science, Helwan University , 11795 Helwan, Cairo, Egypt.|SIM vzw , Technologiepark 935, BE-9052 Zwijnaarde, Belgium.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Barhoum
authors.affiliation: Fraunhofer Institute for Manufacturing Technology and Applied Materials Research , Wiener Street 12, D-28359 Bremen, Germany.|Textile Research Division, National Research Centre , Dokki, Cairo 12311, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Rehan
authors.affiliation: Physical Chemistry and Polymer Science, Department of Materials and Chemistry, Vrije Universiteit Brussels , Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Hubert
authors.initials: H
authors.lastname: Rahier
authors.affiliation: Institut Européen des Membranes, UMR 5635 Université Montpellier CNRS ENSCM , Place Eugene Bataillon, F-34095 Montpellier cedex 5, France.
authors.forename: Mikhael
authors.initials: M
authors.lastname: Bechelany
authors.affiliation: Physical Chemistry and Polymer Science, Department of Materials and Chemistry, Vrije Universiteit Brussels , Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Guy
authors.initials: G
authors.lastname: Van Assche
keywords: calcium carbonate single crystals; citrate reduction mechanism; clusters; heterogeneous nucleation; hot injection; multifunctional fibers; tiny silver nanocrystals