Controlling the Deposition Process of Nanoarchitectonic Nanocomposites Based on {Nb6−xTaxXi12}n+ Octahedral Cluster-Based Building Blocks (Xi = Cl, Br; 0 ≤ x ≤ 6, n = 2, 3, 4) for UV-NIR Blockers Coating Applications

Abstract

The antagonism between global energy needs and the obligation to slow global warming is a current challenge. In order to ensure sufficient thermal comfort, the automotive, housing and agricultural building sectors are major energy consumers. Solar control materials and more particularly, selective glazing are part of the solutions proposed to reduce global energy consumption and tackle global warming. In this context, these works are focused on developing new highly ultraviolet (UV) and near-infrared (NIR) absorbent nanocomposite coatings based on K4[{Nb6-xTaxXi12}Xa6]. (X = Cl, Br, 0 ≤ x ≤ 6) transition metal cluster compounds. These compounds contain cluster-based active species that are characterized by their strong absorption of UV and NIR radiations as well as their good transparency in the visible range, which makes them particularly attractive for window applications. Their integration, by solution processes, into a silica-polyethylene glycol or polyvinylpyrrolidone matrices is discussed. Of particular interest is the control and the tuning of their optical properties during the integration and shaping processes. The properties of the solutions and films were investigated by complementary techniques (UV-Vis-NIR spectrometry, ESI-MS, SEM, HRTEM, etc.). Results of these works have led to the development of versatile solar control coatings whose optical properties are competitive with commercialized material.

High performance {Nb 5 TaX 12 }@PVP (X = Cl, Br) cluster-based nanocomposites coatings for solar glazing applications

“…We assumed that these mass results confirm the other complementary results, especially the Raman and optical absorption. Indeed, the evolution of the optical absorption in water of the whole series from x = 0 to 6 confirmed without ambiguity the presence of the main targeted cluster in the solution [ 41 ].…”

“…The flexibility of homometallic octahedral niobium or tantalum cluster compounds in terms of composition and oxidation state, as well as their nanometric sizes and high solubility make them unique inorganic objects [ 40 , 41 , 45 , 46 ]. The chemical nature of the metallic cluster and the ligands to which it is bound as well as the VEC value make it possible to modulate the optical properties to absorb UV and NIR radiations [ 35–41 ].…”

From Solid-State Cluster Compounds to Functional PMMA-Based Composites with UV and NIR Blocking Properties, and Tuned Hues

“…The strategy presented here can be now extended to the integration in a PMMA matrix of the whole family of [{Nb 6-x Ta x }X i 12 X a 6 ] n− building blocks (X i = Cl, Br; 0 ≤ x ≤ 6, n = 2, 3, 4) starting from the corresponding K 4 [{Nb 6-x Ta x }X i 12 X a 6 ] solid-state precursors [ 16 ]. In particular, it has been recently shown that the [{Nb 5 Ta}Cl i 12 Cl a 6 ] 4− building block exhibits high absorption properties suitable for solar control applications which are complementary to that of ITO [ 65 ].…”

“…Composites were obtained by direct integration of colloidal solutions, containing dispersed K 4 [{Nb 6−x Ta x X i 12 }X a 6 ], in polyethyleneglycol-silicium dioxide (PEG-SiO 2 ) and polyvinylpyrrolidone (PVP) matrices. The use of the latter matrices shows significant drawbacks which are prohibitive for potential applications: (i) after aging, the oxidation of building blocks is observed in PEG-SiO 2 and (ii) PVP is a water-soluble matrix [ 16 , 17 ].…”

A review on functional nanoarchitectonics nanocomposites based on octahedral metal atom clusters (Nb 6 , Mo 6 , Ta 6 , W 6 , Re 6 ): inorganic 0D and 2D powders and films

“…Depending on the application or the property that needs to be enhanced, MC can simply be associated with a binder [80,92,144,[105][106][107] to facilitate the chemical solution deposition (CSD) process or it can be part of a more elaborate devices including several layers, [107,156,160] ink, [187] polymer dispersed liquid crystal, [101] quantum dots and nanocrystals [102,171,192] or DSSC electrodes. [93, 97]…”