Preparation and photochromic behavior of ormosil containing encapsulated AgTCNQ molecules

Abstract

Abstract. Preparation and photochromic behavior of ormosil containing encapsulated AgTCNQ molecules were studied in this paper. The ormosil resulted from hydrolysis and polycondensation of glycidoxypropyltrimethoxysilane, dimethyldimethoxysilane and methyltrimethoxysilane. The time to add AgNO3 water solution into the resultant sol was a key factor to synthesize AgTCNQ molecules inside ormosil matrix. AgTCNQ molecules encapsulated in the ormosil showed different photochromic behavior compared with pure AgTCNQ film: normal photochromic reaction can be realized, while reverse photochromic reaction can not. The "cage" model was used to explain this phenomenon.

Sol–Gel Synthesis and Characterization of Ag and Au Nanoparticles in SiO2, TiO2, and ZrO2 Thin Films

“…The black precipitate in TiO 2 and ZrO 2 sols was identified by XRD (not shown) as metallic silver, while in the case of SiO 2 the brownish precipitate could not be analyzed, but its color suggests that an Ag ϩ -silane adduct is formed more than metallic Ag, in agreement with the findings of other authors. 26 The brownish color of the sols could then be due to charge transfer absorption in the Ag ϩ -containing adduct, since the electronic spectra of the corresponding SiO 2 sol exhibit a band with a maximum at about 350 nm. For further support of the model of the reduction of Ag ϩ , based on the role of the oxide former (Si, Ti, or Zr) and of the groups bound to it, it must be pointed out that SiO 2 sols were also prepared from a TEOS/MTES (methyltriethoxysilane, CH 3 Si(OC 2 H 5 ) 3 ) system, again without using any ligand for Ag ϩ , and the precipitation was faster and enhanced with respect to the SiO 2 sol prepared from TEOS only.…”