• CNU

• Physique/Matière Condensée/Science des matériaux
  

Over the past decade, significant effort has been directed towards the elucidation of synthesis/structure/function correlations to guide the development of synthetic strategies for controlling the composition, size and shape of nanomaterials. In this context, organic–inorganic nanohybrids incorporating bridged silsesquioxanes have been of particular interest, due to their versatility and the structural control that can be achieved through independent modulation of the properties of the organic bridge and inorganic moieties. Such strategies have also been applied to the production of thin films on a variety of substrates, driven by the continuing need to develop new and enhanced materials with nanostructures engineered over multiple length scales for applications in electronics, optics, sensing, ferromagnetics, shape-selective membranes, etc. In this talk, I will first describe the mechanisms that control the evolution of the organized solid from energy efficient sol−gel processing: self-assembly, hydrolysis, polycondensation of precursor molecules, and nucleation and growth of the hybrid solid in solution. The preparation of thin films will be then given [1,2]. The influence of key chemical (particularly pH and ageing time) and physical parameters (spinning speed) on the morphology of the resulting coatings will be depicted, and a model describing the structural evolutions of the coatings will be presented as a general approach for producing self-structured coatings under far-from-equilibrium conditions [3]. Finally I will present application of these nanomaterials in the domain of transparent luminescent solar concentrators. [3] [1] Langmuir 2013, 29, 5581−5588 [2] Physical Chemistry Chemical Physics 2019 accepted DOI: 10.1039/C8CP06625F [3] Physical Chemistry Chemical Physics 2016 18, 7946 [4] ACS Appl. Mater. Interfaces 2015 7(16), 8770 -8778

Over the past two decades significant efforts have been directed towards the elucidation of synthesis/structure/function correlations to guide the development of synthetic strategies for controlling the composition, size and shape of nanomaterials. In this context, organic–inorganic nanohybrids incorporating bridged silsesquioxanes have been of particular interest, due to their versatility and the structural control that can be achieved through independent modulation of the properties of the organic bridge and inorganic moieties. Such strategies have also been applied to the production of thin films on a variety of substrates, driven by the continuous need to develop new and enhanced materials with nanostructures engineered over multiple length scales for applications in electronics, optics, sensing, ferromagnetic, shape-selective membranes, etc. In this talk, I will first present a fundamental study of the nanostructuring mechanisms of model hybrid silica. Our experimental investigation was performed using an in operando approach (vibrational spectroscopies under pressure, light diffusion, microscopy) coupled with DFT calculations. Parameters controlling the evolution of the system during sol−gel processing: supramolecular interactions, hydrolysis, polycondensation, and nucleation and growth of the hybrid solid in solution were investigated. The relation between structural properties and applications will be then highlighted1-4.