How Do Nano Particles Enhance Material Properties?

[ajayguhan]

I know what is lattice constant but it has been given that nano particles have reduced lattice constant due to huge fraction of atoms being in surface. How come the lattice constant of nano particles reduced due to high number of atoms present in surface?

Why do the surface area, hardness, strength, corrosion resistance, wear resistance, electrical resistance all these properties increase in cases nano particles? There maybe some exception but this is the general trend is there any reason behind it?

 

[UltrafastPED]

Surface forces result in changes to the structure of a crystal due to un-paired bonds at the surface.

As particles grow smaller the surface area to volume ratio increases ... and so you end up with different properties due to the surface forces.

 

[ajayguhan]

Why does the surface area increase as the nano particle grows smaller in size.

 

[UltrafastPED]

Ratio of surface atoms to total atoms. In the limit they are all on the surface as with a buckyball.