Photochromism of Clay−Diarylethene Hybrid Materials in Optically Transparent Gelatin Films

Abstract

The dispersion of clay−diarylethene hybrid materials into an ionic biopolymer, gelatin, was investigated for the successful preparation of highly functional photochromic films. A mixture of the gelatin and the clay−diarylethene hybrid material dispersed in aqueous N,N-dimethylformamide (DMF) was cast on a glass plate. The film obtained after drying at 50 °C was transparent in the visible light region and showed highly reversible coloration and decoloration by alternative irradiation with UV light of around 300 nm and visible light of around 600 nm. X-ray diffraction analysis indicated that the diarylethene molecules were able to remain in the clay interlayers without spilling into the bulk gelatin matrix. Moreover, UV−visible polarized spectroscopic analysis revealed the clay−diarylethene hybrid materials to be oriented essentially parallel to the glass plate, indicating that the diarylethene molecules are aligned as inclined interdigitated monolayers within the clay interlayers.

Optical Properties of Functional Hybrid Organic–Inorganic Nanocomposites

“…Transparent thin films were prepared by dispersing fine clay particles intercalated by organic compounds within a gelatin matrix. [125] 4. Nonlinear Optics…”

Photochromic Intercalation Compounds

“…Intercalation of another cationic diarylethene, 1,2-bis(2'-methyl-5'-(1''-methyl-3''-pyridinio)thiophen-3'-yl)-3,3,4,4,5,5-hexafluorocyclopentene (1, the molecular structure is shown in Figure 3a), into montmorillonite was reported [33,144]. As schematically shown in Figure 3b, from XRD and UV-Vis polarized spectroscopy, the cationic diarlyethene 1 was shown to be anistropically accommodated with DMF in a gelatin film involving the dye-montmorillonite hybrid,.…”

Some features associated with organosilane groups grafted by the sol–gel process onto synthetic talc-like phyllosilicate

“…Thus, a mixture of organosilane precursors lead to multifunctional layered magnesium organosilicates [14]. Although the organic moiety attached to the inorganic backbone restricts the use of high temperature, these phyllosilicates can be applied as sorbents, environmental barriers, polymer fillers, catalytic supports or chemical sensors [26]. The ferromagnetic properties in talc-like cobalt phyllosilicates were also determined [27].…”