introduction to nanomaterials materials & nanotechnology dr raymond whitby
Post on 19-Dec-2015
217 views
TRANSCRIPT
Introduction to NanomaterialsMaterials & Nanotechnology
Dr Raymond Whitby
“We define (the nanoscale) to be from 100nm down to the size of atoms (approximately 0.2nm) because it is at this scale that the properties of materials can be very different from those at a larger scale”
The Royal Society
Geometry
x
y
z
Nanomaterials are materials that have a structural component smaller than 100 nanometers (nm) in at least one dimension
100nm
Componentry
atom cluster / particle
Single polymerstrand
benzene
At present there is no clear differentiation between nanomaterials and molecules, therefore, traditional chemistry can be viewed as a form of nanoscience.
Deciding factors? Stability, chemical reactivity or inertness, solubility, inorganic materials?
Two main reasons cause nanomaterial properties to significantly change from their bulk scale equivalents, those being an increase in the relative surface area and quantum effects. These can led to dramatic changes or enhancement of their fundamental properties such as material strength, electrical or thermal characteristics and heightened (bio)chemical reactivity.
Importance of nano (1)
30nm = 5% of atoms on surface
10nm = 20% of atoms on surface
3nm = 50% of atoms on surface
N.B. not to scale!