Transcript Document

An Early Nanotechnologist?
Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773)
...At length being at Clapham, where there is, on the Common, a large
Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I
saw it spread itself with surprising Swiftness upon the Surface ... the Oil
tho' not more than a Tea Spoonful ... which spread amazingly, and
extended itself gradually till it reached the Lee Side, making all that
Quarter of the Pond, perhaps half an Acre, as smooth as a Looking
Glass....
QuickTime™ and a
Motion JPEG OpenDML decompressor
are needed to see this picture.
QuickTime™ and a
Motion JPEG OpenDML decompressor
are needed to see this picture.
... the Oil tho' not more than a Tea Spoonful ...
... perhaps half an Acre
CHALLENGE: How thick was the film of oil?
Volume = (Area)(Thickness)
V=At
It can be determined that the
thickness is about 1 nanometer
(classroom activity)
A monolayer film (single layer of molecules)
Langmuir film
1 nm thick
An Early Nanotechnologist!
... the Oil tho' not more than a Tea Spoonful ...
... perhaps half an Acre
CHALLENGE: How thick was the film of oil?
Volume = (Area)(Thickness)
V=At
t = V/A
V = 1 teaspoonful
A = 0.5 acre
2 cm3
20,000,000 cm2
~ 2 cm3
=
~ 2,000 m2
= 0.0000001 cm
= 1 x 10-7 cm
= 1 x 10-9 m
= 1 nanometer (nm)
20,000,000 cm2
Langmuir
Film
hydrophobic end
e.g., steric acid
pressure
of an amphiphilic
molecule
monolayer film
water
hydrophilic end
QuickTime™ and a
TIFF (LZW) decompressor
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Langmuir-Blodgett Film
Must control movable
barrier to keep constant
pressure
multiple dips multiple layers