Sheets exfoliated

Fig. 8.6 TEM images of (A) exfoliated sheets of AMP in water (scale bar = 200 nm), and (B) cryo-TEM image of exfoliated AMP organoclay sheets viewed edge-on (scale bar = 50nm).

Nanoparticles of metals such as Au, Ag, Pd and Pt embedded in exfoliated sheets of aminociays of the type R8Si8Mgs0lfi-(OH)4, where R = CH2CH2NH2 are entirely water soluble. These sheets of the composite come to the organic-aqueous interface on addition of alkane thiols to the aqueous layer. 

In the present study the property of the aminociays wherein protonation of the amino groups in water is accompanied by exfoliation has been exploited.15 Thus metal nanoparticle composites formed by the exfoliated aminoclay sheets by carrying out the reduction of metal precursors in the presence of the clay have been investigated. Besides being entirely water soluble, the exfoliated sheets of aminoclay-Au nanoparticle composites move to the organic/aqueous interface in the presence of an alkanethiol. 

In conclusion, exfoliated sheets of Mg-phyllo(organo)silicates containing pendant amino groups have been used to stabilize Au, Ag, Pd and Pt nanopartides. The nanoparticle-decorated day sheets can be easily dispersed in water. These metal nanopartides... 

Layered compounds provide unique character for electron-transfer processes owing to their low dimensionality. Especially layered materials with ion-exchange and/or intercalation capabilities show behavior that is not seen in so-called bulk-type materials. Layered materials, which have been often used in studies of photoelectron transfer as well as photocatalysis, may be classified into two groups compounds in which the host layers work as an active component for the photoexcitation and electron-transfer reactions, and materials in which the layers are inert for electron-transfer processes. Examples of the former are layered titanates and niobates and of the latter are clays. In the latter case, photoactive materials are intercalated in the interlayer spaces. Recently, the exfoliation of various layered compounds has become possible and artificial assemblies consisting of these exfoliated sheets have been formed. Electron transfer in such assemblies is also an attractive subject in this field. 

Fig. 11 (a) Chemical structure of a tetrafluoro-triptycene-based monomer (fantrip) and the corresponding 2D-polymer, poly(fantrip). (b) A single crystal of the monomer before and after irradiation (223 K, 460 nm, 80 min), (c) A single crystal of the monomer before and after irradiation (223 K, 460 run, 150 min) followed by a second irradiation (223 K, 400 nm, 70 min). The bottom panel shows SEM and AFM images of exfoliated sheets. Reproduced with permission from [72], Copyright 2014 Macmillan Publishers Ltd... 

Polymer melt intercalation (involving a polymer and a layered siUcale mixture heated under discontinuous or continuous shear above the softening point of the polymer thus, the polymer chains diffuse from the molten polymer into the silicate galleries and form intercalated or exfoliated sheets). 

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