Biology Reference
In-Depth Information
FIGURE 2.4
Agnes Pockles (1862
e
1935). Courtesy of the Archive of Braunschweig Technical University.
Soon after her death in 1935 Nobel Laureate Irving Langmuir, 'The Dean of Surface Chem-
ists', stated that her methodology 'laid the foundation for nearly all modern work with films
on water'.
Irving Langmuir: (1917)
At a time when nearly all world-renowned scientists were European, Irving Langmuir
(
Figure 2.5
) was born in America and did his work while employed by General Electric
(GE) in Schenectady, New York. While at GE he became famous for developing the nitrogen
filled incandescent light bulb. Because of the large income the new bulb made for GE, he was
allowed free reign to experiment on just about whatever he pleased, including oil/water
interface physics.
In 1917, Langmuir also repeated the Franklin experiment and reported the molecular
size of triolein to be 13
˚
[9]
. Langmuir is credited with refining air/water interface
studies into a precise science. For this contribution he was awarded the 1932 Nobel Prize
in Chemistry
[10]
. Langmuir was one of the first to understand that molecules were not
just simple spheres. He envisioned the asymmetric molecular shape of surfactants (mole-
cules that accumulate at the air/water interface) having a dual personality
with one
region being hydrophobic and another being hydrophilic. In his 1917 Journal of the
American Chemical Society paper he wrote 'Oleic acid on water forms a film one molecule
e
