Chemistry Reference
In-Depth Information
Figure 2.8.
Typical surfactant structure with common hydrophile and hydrophobe structures.
each of these classi
c structure on the
hydrophile (e.g., sulfonate and carboxylate) or other structural features (e.g., block
copolymers) [34]. The hydrophobic part of the surfactant, frequently called the tail,
consists of linear or branched alkyl groups, substituted alkyl aryl groups, hydrophobic
oligomers of alkylene oxides such as polypropylene oxide (PPO), silicone-containing
oligomers, or per
cations, there are subclasses based on the speci
uorinated alkyls. Surfactants may be produced synthetically, derived
from natural sources (e.g., fatty acid salts), or be present in biological systems naturally
(e.g., bile acid salts). The structures of some common surfactants are shown in Figure 2.9.
2.2.1 Interfacial Properties
One of the characteristic properties of surfactants is their tendency to adsorb at interfaces such
as liquid
-
air, liquid
-
liquid, and solid
-
liquid interfaces. This results in a number of useful
Figure 2.9.
Common surfactant chemical structures.
