Transparent Polysilsesquioxane Films Obtained from Bridged Ureasil Precursors: Tunable Photoluminescence Emission in the Visible Region and Filtering of UV‐Radiation

Abstract

Bridged ureasil precursors were synthesized by the reaction of either ethylenediamine (1 mol) or m‐xylylenediamine (1 mol) with isocyanatepropyltriethoxysilane (2 mol). Transparent polysilsesquioxane films were obtained by the hydrolytic condensation of the pure precursors or their co‐condensation in a 50:50 molar ratio. Films based on pure ureasil precursors showed a blue photoluminescent emission band assigned to the photoinduced proton‐transfer among H‐bonded urea groups and the subsequent radiative recombination of ionized groups. Films synthesized by the co‐condensation of both precursors exhibited a significant red‐shift of their absorption, excitation, and emission spectra, associated to de‐localization of H‐bonds, and a high absorption of UV‐radiation.

Dispersion of gold dodecanethiolate in a silsesquioxane film with pendant dodecyl chains: from photoluminescent materials to gold nanocomposites

“…As silsesquioxanes show photoluminescence [21,[28][29][30], this property was analyzed in the synthesized films. Absorption spectra of the films are shown in Fig.…”

Clean Singlet Oxygen Production by a ReI Complex Embedded in a Flexible Self-Standing Polymeric Silsesquioxane Film

“…One of the most-studied properties of SSO films is their capacity for emitting light in the visible range of the electromagnetic spectrum upon optical or electrical excitation. Strategies for tuning the photophysical and mechanical properties of SSO materials usually involve the modification of the composition of its organic bridging moieties, variation of the synthesis conditions, and the incorporation of nonbound matrix dopants such as organic dyes, Eu 3+ , and other lanthanides, among others. Also, the ability of SSO films to efficiently and homogeneously disperse a large number of dopants such as Au , and Ag nanoparticles, porphyrins, and other organic dyes within its polymeric matrix can be tuned by introducing alkyl pendant groups.…”

Efficient synthesis of SiOC glasses from ethane, ethylene, and acetylene-bridged polysilsesquioxanes

“…These materials were used as received without purification. Bis(triethoxysilyl)acetylene was prepared as reported previously [16]. Solid state magic angle spinning (MAS) 13 C and 29 Si NMR spectra were obtained on a Varian 600PS spectrometer using a 6 mm ϕ spinner.…”

“…Of those, organically bridged polysilsesquioxanes, which are synthesized via the sol-gel process of organic group-bridged trialkoxysilanes [(R′O) 3 SiRSi(OR′) 3 ] have attracted recent attention. In these materials, the organic unit (R) bridging two Si atoms expands silica network as a spacer, leading to the use for various functional materials, such as catalysts, low density materials, and separation membranes [15][16][17][18][19][20]. The bridged polysilsesquioxanes have been also investigated as precursors of SiOC glasses [21,22].…”