What is Carbon ?

** Carbon can be made in numerous allotropic 

types: crystalline diamond, graphite, noncrystalline 

glassy carbon, and quasicrystalline pyrolitic 

carbon.

** The crystalline structure of carbon, as utilised in 

implants, is alike to the graphite structure.

** The bonding between the levels is more

 powerful than the van der Waals force, it has been 

proposed that the layers are cross-linked.

Some allotropes of carbon: 

 a) diamond; 

 b) graphite; 

 c) lonsdaleite;

 d–f) fullerenes (C60, C540, C70);

 g) amorphous carbon; 

 h) carbon nanotube.

** The hexagonal layers are not flawlessly 

organised. 

** Properties of individual crystallites appear to be 

highly anisotropic. although, if the crystallites are 

randomly dispersed, the aggregate becomes 

isotropic.