Polyurethane nanocomposites with high content of red NIR luminescent transition metal clusters are presented. The gas permeability of the hybrid material is controlled by adjusting the hard/soft segment ratio of the organic matrix structure leading to a drastic and reversible enhancement of cluster luminescence depending on the molecular oxygen concentration in its surrounding atmosphere.
International audienceRecently, Nanoarchitectonics has been introducedas a new concept that refers to a technology systemfor arranging nanoscale structural units in a requiredarchitecture. Multifunctional properties are achieved by acombination of several materials in a well-defined architecture.In the frame of this concept, composite nanoarchitecturesrepresent a new class of nanostructured entitiesthat integrate various dissimilar nanoscale building blocksincluding clusters, particles, wires and films. The heterogeneouscomposite nanostructured materials are composedby definition of multi-(nano)components, each tailored toaddress different requirements. As one of the nanocomponents,nanometer sized metal clusters (\2 nm), whichconsist of less than a few dozens of metal atoms, could bedefined as a link between atom and nanoparticle. In thispaper, we will focus on our results on new nano-compositesinvolving Mo6 atom nanosized cluster units for optical,nanobiotechnology, energy and environmental applications
New luminescent poly(methylmethacrylate) (PMMA) nanocomposites with high content of different hexanuclear octahedral cluster building blocks, namely [Mo6I8(C2F5COO6)](2-), [Re6Se8(CN)6](4-) and [W6Cl14](2-) have been prepared by free-radical polymerisation. To do so, cluster complexes bearing a polymerisable ammonium counter-cation have been synthesised. In this way, we demonstrate that ionic assembling is a powerful tool to functionalise easily any type of anionic cluster units to be introduced in a PMMA organic matrix. All samples remain homogeneous, stable during several months, and retain the luminescence properties of the cluster precursor.
Accepted 04 Dec 2013International audienceThe hybrid strategy is a powerful approach to design functional materials by combining inorganic dyes with an organic matrix. However, introducing high contents of inorganic species within the hybrid material is a real challenge that requires a perfect balance between the interactions of both components to avoid mainly phase segregation problems. Based on our demonstration on an anionic molybdenum cluster, we present a general method to introduce high contents of such class of nanometre sized inorganic molecular deep red dyes in a polymer matrix. Our strategy exploits the physical interactions between the organic and inorganic parts of the hybrid material and allows a high cluster rate to be introduced (up to 50 wt%) in the polymer matrix. The resulting hybrids are remarkably stable even after several months of ageing. Moreover, the Mo clusters maintain their intrinsic deep red luminescence properties while the polymer organic matrix fully maintains its processability, thanks to the di-anionic character of the Mo6 clusters. Such materials show promising prospects in applications needing deep red emitters
Drop on Demand inkjet printing is an attractive method for device fabrication. However, the reliability of the key printing steps is still challenging. This explains why versatile functional inks are needed. Epoxy based ink described in this study could solve this critical issue because it can be printed with low drawbacks (satellites droplets, long-lived filaments, etc.). Moreover, a wide concentration range of solute allows the fabrication of films from thin to high aspect ratio. Optimizing experimental parameters (temperature, overlap) and ink composition (single or cosolvent) is useful to tune the film profile. As a result, many shapes can be obtained such as donuts or hemispherical caps for a droplet and smooth or wavy shape for a thin film. This study demonstrates that epoxy based versatile ink can be used in numerous fields of applications (organic electronics, optics, sensors, MEMS, etc.). To prove this assertion, organic field effect transistors and light emitting films have been fabricated.
To cite this version:Chrystelle Neaime, Maria Amela-Cortes, Fabien Grasset, Yann Molard, Stéphane Cordier, et al..Time-gated luminescence bioimaging with new luminescent nanocolloids based on [Mo6I8(C2F5COO)(6)](2-) metal atom clusters.
We report the photoluminescence (PL) and cathodoluminescence (CL) properties of face-capped [Mo6Xi
8La
6]2− (X = Cl, Br, I; L = organic or inorganic ligands) cluster units. We show that the emission of Mo6 metal atom clusters depends not only on the nature of X and L ligands bound to the cluster and counter-cations, but also on the excitation source. Seven members of the AxMo6Xi
8La
6 series (A = Cs+, (n-C4H9)4N+, NH4
+) were selected to evaluate the influence of counter-cations and ligands on de-excitation mechanisms responsible for multicomponent emission of cluster units. This study evaluates the ageing of each member of the series, which is crucial for further energy conversion applications (photovoltaic, lighting, water splitting, etc.).
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