Page 33 - Introduction to Colloid and Surface Chemistry
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24 Kinetic properties
0,08 E
0.06 :
0 0.2 0.4 0.6 0.8 } .0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
Hydration
Mass of water/mass of protein
Figure 2.1 Values of axial ratio and hydration compatible with various frictional
2
ratios (contour lines denote flf n values) (By courtesy of the authors ** and Reinhold
Publishing Corporation)
The motion of individual particles is continually changing direction
as a result of random collisions with the molecules of the suspending
medium, other particles and the walls of the containing vessel. Each
particle pursues a complicated and irregular zig-zag path. When the
particles are large enough for observation, this random motion is
referred to as Brownian motion, after the botanist who first observed
this phenomenon with pollen grains suspended in water. The smaller
the particles, the more evident is their Brownian motion.
Treating Brownian motion as a three-dimensional 'random walk',
the mean Brownian displacement x of a particle from its original
