Metal-based organogelators

The dye-based organogels also act as stimuh-responsive materials, because they are physically formed by noncovalent interactions, and are responsive to physical or chemical stimuli such as fight, heat, proton, metal, shrinking. 

Double-walled nanotubes of transition metal oxides Ti02, Ta205, and Zr02, as well as binary TiO /ZrO were prepared with a cholesterol-based organogel [27]. The gelator serves as both template and catalyst for the nanostructure formation. The formation of double-walled nanotubes is due to the condensation of the transition metal oxide on both outer and inner surfaces of the tubular structure of gel fibers. 

Nakamura and Matsui [71] prepared silica nanotubes as a spin-off product of sol-gel synthesis wherein tetraethylorthosilicate (TEOS) was hydrolyzed in the presence of ammonia and D, L-tartaric acid. Ono et al. [72] showed that certain cholesterol derivatives can gelate tetraethyl orthosilicate (TEOS) to obtain tubular silica structures. Using cholesterol based gelators nanotubes of transition metal (Ti, V and Ta) oxides can also be prepared. The organogelators used in these processes are chiral diamino... 

Chirality can be induced into the siHca structure by the use of either a cholesterol based gelator with an azacrown moiety in the presence of metal cations [53] or organogels comprised of chiral diaminocyclohexane derivatives [54]. Helical ribbons and double layered nanotubes (diameter 500 nm) composed of titania can also be obtained [55]. 

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