Fig. 6
FESEM micrographs of nanostructures produced at various rotational speeds during the centrifugal process: 200 (a) low magnification, nanotube (inset); 400 (b) low magnification, nanotube (inset); 800 (c) low, (d) high magnification, nanotube and nanorod (inset); 1000 (e) low magnification, nanotube and nanorod (inset); 2000 (f) low magnification, nanotube and nanorod (inset); 3000 (g) low magnification, nanotube and nanorod (inset); 4000 (h) low magnification with closed-end tips (inset), (i) high magnification with free-standing nanostructures (inset)