ABSTRACT
Nanotechnology researchers
share their views on the definition, shape, and sizes of nano-objects. They
state that nano-objects can be in the form of a colloidal suspension, an
aggregated powder, or supported on some surface, and that imaging and size
characterization results do not represent these objects in their native state.
Nano-objects in a colloidal suspension are kinetically stabilized against
aggregation by a coating of charged species, organic ligands, or polymer. The
volume fraction and thickness of such a coating can be significantly large when
the nano-object is less than 10 nm in size. The researchers state that the size
of a nano-object needs to include the coating thickness. Nano-objects that are
permanently in aggregated form, such as those prepared through gas-phase
methods, have an additional length scale to consider, including the size of the
aggregated particle.
