Amorphous carbon nanorings have been obtained from carbon nanostructures derived from the carbonization of Pluronic P123 polymer inside mesoporous SBA-15 rods grown in a porous alumina membrane. The presence of the alumina and the silica walls restricts the diffusion of oxygen during calcination and facilitates the carbonization of Pluronic P123. The resulting carbonized nanostructures self-assemble around the water droplets in the presence of CCl4, and form ring structures with diameters between 2 and 10 mu m and a rim thickness of similar to 50 nm. (c) 2006 Elsevier B.V. All rights reserved.