Figure 8. Bundles of aligned filaments of hydroxyapatite prepared with high concentrations of AOT [sodium bis-(2-ethylhexylsulfosuccinate)] and a low concentration of water, with a small quantity of m-xylene co-solvent. Insert: Electron diffraction pattern of the bundles showing (arrow) an arc pattern, confirming the alignment of the hydroxyapatite filaments. (Reprinted from Fowler et al., 2005, with permission from The Royal Society of Chemistry.)