The document discusses the ball milling method for producing nano materials. It involves using a ball mill, which rotates around a horizontal axis partially filled with the material to be ground plus grinding media like balls. The balls crush the solid material into nano crystallites due to the gravity and kinetic forces as they rotate at high energy inside the container. Some examples given are using ball milling to produce carbon nanotubes, boron nitride nanotubes, metal oxide nano crystals like cerium oxide and zinc oxide. Ball milling of graphite can also produce nanostructured graphite for hydrogen storage applications.

1. BALL MILLING METHOD
By
Aravind N. B

2.  Nano materials can be defined as those
materials which have structured
components with size less than 100nm at
least in one dimension.
 Nanotechnology is an advanced
technology, which deals with the synthesis
of nano-particles, processing of the nano
materials and their applications.

3.  Begin with atoms and
molecules(bottom), which react under
chemical and physical circumstances to
form nanostructure.
 Eg. Chemical Vapor
Deposition(CVD), Atomic Layer
Deposition(ALD), Crystal Growth ,etc

4.  Begin with Bulk Materials(Top) that are
subsequently reduced into
Nanostructures(Down) by the way of
physical, chemical and mechanical
processes.
 Eg: Mechanical-ball milling
, extrusion, grinding,etc

5.  Ball milling is a method of production of
nano materials.
 This process is used in producing metallic
and ceramic nano materials.
 These mills are equipped with grinding
media composed of wolfram carbide or
steel.
 Ball mills rotate around a horizontal axis
,partially filled with the material to be
ground plus the grinding medium.

7.  The balls rotate with high energy inside a container
and then fall on the solid with gravity force and kinetic
and hence crush the solid into nano crystallites.

10.  Generation of curved or closed-shell carbon
nanostructures by ball-milling of graphite
 Carbon scrolls produced by high energy ball
milling of graphite
 Nanoporous carbon produced by ball milling
 The nucleation and growth of carbon
nanotubes in a mechano-thermal process.
 Carbon nanotubes formed in graphite after
mechanical grinding and thermal annealing.

11.  Carbon microspheres produced by high
energy ball milling of graphite powder
 Carbon tubes produced during high-
energy ball milling process
 Highly curved carbon nanostructures
produced by ball-milling
 Low energy pure shear milling: A
method for the preparation of graphite
nano-sheets

12.  The significant advantage of this method is
that it can be readily implemented
commercially.
 Ball milling can be used to make carbon
nanotubes and boron nitride nanotubes.
 It is a preferred method for preparing metal
oxide nano crystals like Cerium(CeO2) and
Zinc Oxide (ZnO).

13.  Ball milling of graphite under a hydrogen
atmosphere is an effective method of
producing nanostructured graphite which is
able to store an appreciable amount of
hydrogen.
 Nanostructured graphite has potential for
use as a low-cost in energy store, for vehicles
and stationary hydrogen-energy
applications.