Hollow containing metal nanoparticles

Many fibers composed of natural polymers contain uniaxially oriented anisotropic hollow spaces in which metal particles can crystallize under appropriate conditions. As a consequence, the impregnated fibers contain anisotropic assemblies of metal nanoparticles that induce anisotropic optical properties... 

Macanas J, Ouyang L, Bruening M L, Munoz M, Remigy J C and Lahitte J F (2010), Development of polymeric hollow fiber membranes containing catalytic metal nanoparticles , Catal Today, 156,181-186. 

Laser ablation of the layered structure under inert atmosphere has been used to prepare IF-M0S2 and WS2 with metal encapsulated and hollow onionlike structures at 450, 650, 850, and 1050°C [66]. The nanoparticles of WS2 grown at 450 and 650°C contain three concentric WS2 outer layers with metals encapsulated within. Laser ablation at higher temperature (1050°C) yields WS2 nanoparticles with hollow closed-cage polyhedral nanotubes these have diameters ranging from 10 to 15 nm and contain 4-8 concentric WS2 shells. Similar results have been obtained for M0S2 at 1050°C. 

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