| Autor: |
Lermusiaux L; University Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, 33600 Pessac, France., Roach L; University Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, 33600 Pessac, France., Lehtihet M; University Bordeaux, CNRS, Solvay, LOF, UMR 5258, 33608 Pessac, France., Plissonneau M; Solvay R&I, 52 rue de la Haie Coq, 93306 Aubervilliers, France., Bertry L; Solvay R&I, 52 rue de la Haie Coq, 93306 Aubervilliers, France., Buissette V; Solvay R&I, 52 rue de la Haie Coq, 93306 Aubervilliers, France., Le Mercier T; Solvay R&I, 52 rue de la Haie Coq, 93306 Aubervilliers, France., Duguet E; University Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, 33600 Pessac, France., Drisko GL; University Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, 33600 Pessac, France., Leng J; University Bordeaux, CNRS, Solvay, LOF, UMR 5258, 33608 Pessac, France., Tréguer-Delapierre M; University Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, 33600 Pessac, France. |
| Abstrakt: |
We describe a new approach to making ultrathin Ag nanoshells with a higher level of extinction in the infrared than in the visible. The combination of near-infrared active ultrathin nanoshells with their isotropic optical properties is of interest for energy-saving applications. For such applications, the morphology must be precisely controlled, since the optical response is sensitive to nanometer-scale variations. To achieve this precision, we use a multi-step, reproducible, colloidal chemical synthesis. It includes the reduction of Tollens' reactant onto Sn 2+ -sensitized silica particles, followed by silver-nitrate reduction by formaldehyde and ammonia. The smooth shells are about 10 nm thick, on average, and have different morphologies: continuous, percolated, and patchy, depending on the quantity of the silver nitrate used. The shell-formation mechanism, studied by optical spectroscopy and high-resolution microscopy, seems to consist of two steps: the formation of very thin and flat patches, followed by their guided regrowth around the silica particle, which is favored by a high reaction rate. The optical and thermal properties of the core-shell particles, embedded in a transparent poly(vinylpyrrolidone) film on a glass substrate, were also investigated. We found that the Ag-nanoshell films can convert 30% of the power of incident near-infrared light into heat, making them very suitable in window glazing for radiative screening from solar light. |
