Characteristics of flexible supramolecular assembly of dioleyldimethylammonium ion confined in a two dimensional nanospace studied by the host-guest reactions

Organophilic Clay with Useful Whiteness

An organophilic clay was obtained by the intercalation of dioctadecyldimethylammonium ions into the interlayer space of a purified bentonite. The organophilic clay was characterized by its excellent whiteness, which originated from the used purified bentonite with a low content of colored impurities, suitable for its practical application in paints, cosmetics, polymer additives, etc. The dioctadecyldimethylammonium-bentonite clay was applied as a support to accommodate polyaromatic molecules to afford luminescent hybrids with high luminescence efficiency, showing its usefulness as a component of photofunctional hybrid materials.

Intercalation of a Cationic Cyanine Dye Assisted by Anionic Surfactants within Mg-Al Layered Double Hydroxide

An original route for the intercalation of a 1,1'-diethyl-2,2'-cyanine iodide (PIC) cationic dye, through the use of anionic surfactants as vector/carrier phases, within Mg-Al layered double hydroxide (LDH) was investigated. From the data acquired from complementary techniques (X-ray diffraction, infrared and UV-visible spectroscopies, thermogravimetry, and fluorimetry), it appears that both the intercalation and aggregation states of the cationic dye within the internal structure of LDH mainly depend on both the surfactant state (monomer form or spherical micelle) and its amount. The intercalation of PIC at a low molar ratio to the anionic surfactant leads to the formation of J-aggregates with singular fluorescence properties that mainly depend on the nature of the anionic surfactant used for the co-intercalation process. The results obtained in this study open new routes for the intercalation of cationic species, assisted by anionic surfactants, within LDHs.

Highly Luminescent Inorganic-Organic Hybrids with Molecularly Dispersed Perylene

A highly photoluminescent material was obtained by the incorporation of perylene into an inorganic-organic hybrid film. Octosilicate, a layered alkali silicate, was modified with a cationic surfactant, dioleyldimethylammonium ion, to accommodate perylene molecularly and uniformly. The perylene-doped dioleyldimethylammonium octosilicate films were fabricated by simply casting the toluene solution of perylene with dispersed dioleyldimethylammonium octosilicate on substrates. Near-unity photoluminescence quantum efficiency was achieved for hybrids containing a high concentration of perylene.

Efficient Negative Photochromism by the Photoinduced Migration of Photochromic Merocyanine/Spiropyran in the Solid State

Efficient negative photochromism was achieved by the photoinduced migration of merocyanine in mesoporous silica to an organophilic clay as spiropyran. Depending on the nature of the organophilic clays (dioctadecyldimethylammonium and dioleyldimethylammonium clays), important differences in the negative photochromisms and the thermal coloration were observed; the dioleyldimethylammonium clay gave a higher yield (98%) and faster reaction (half-life t_1/2 = 2.8 h) than the dioctadecyldimethylammonium clay (94% and t_1/2 = 3.2 h) of the negative photochromism, indicating the important role of the surfactant assembly to control the molecular diffusion.