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Most surfactants are organic compounds with hydrophilic "heads" and hydrophobic "tails." The "heads" of surfactants are polar and may or may not carry an electrical charge. The "tails" of most surfactants are fairly similar, consisting of a hydrocarbon chain, which can be branched, linear, or aromatic. Fluorosurfactants have fluorocarbon chains.
Surfactants are usually composed of a hydrocarbon chain and a polar head group. Increasing the length of the hydrocarbon chain increases the Krafft temperature because it improves Van der Waals forces. Moreover, since Krafft point is related to solid-liquid transition, better-packed polar heads within surfactant crystals increase Krafft ...
The driving mechanism for micellization is the transfer of hydrocarbon chains from water into the oil-like interior. This entropic effect is called the hydrophobic effect . Compared to the increase of entropy of the surrounding water molecules, this hydrophobic interaction is relatively small.
In chemistry, a fatty amine is loosely defined as any amine possessing a mostly linear hydrocarbon chain of eight or more carbon atoms. They are typically prepared from the more abundant fatty acids, with vegetable or seed-oils being the ultimate starting material. [1] As such they are often mixtures of chain lengths, ranging up to about C22.
Alkyl sulfates consist of a hydrophobic hydrocarbon chain, a polar sulfate group (containing an anion) and either a cation or amine to neutralize the sulfate group. Examples include: sodium lauryl sulfate (also known as sulfuric acid mono dodecyl ester sodium salt) and related potassium and ammonium salts.
The anion consists of a nonpolar hydrocarbon chain and a polar sulfate end group. The combination of nonpolar and polar groups confers surfactant properties to the anion: it facilitates dissolution of both polar and non-polar materials.
In addition to a longer hydrocarbon chain in which there must be at least one double bond (hence the name "olefin"), it has an anionic sulfonate headgroup with a sodium ion as a counterion. The sulfonate group is negative in aqueous solution, which is why the α-olefin sulfonates are among the anionic surfactants.
Hydrocarbon-based surfactants are an example group of amphiphilic compounds. Their polar region can be either ionic, or non-ionic. Some typical members of this group are: sodium dodecyl sulfate , benzalkonium chloride , cocamidopropyl betaine (zwitterionic), and 1-octanol (long-chain alcohol, non-ionic). [citation needed]