Bolaamphiphile

Bolaamphiphiles (also called " Bolatenside " or simply " bolas ") is a special type of amphiphilic molecules; they have at least two hydrophilic head groups, which are separated by a sufficiently long hydrophobic moiety. The name " Bola " has its origin in the similarity of the molecular shape to a throwing weapon of indigenous peoples and was introduced in 1951 by Raymond M. Fouss and David Edelson.

Structure

The molecules are divided according to their membership of the surfactants in hydrophilic and hydrophobic regions. Hydrophilic units are, in essence, carboxyl, ammonium, polyethoxy groups, as well as sugar monomers, while the hydrophobic moiety of alkyl and phenyl groups is formed. Of particular importance have the synthetic bolas, which are obtained by condensation and coupling reactions.

Properties

Bolatenside surfactants have, in comparison to using a single head group to a higher solubility in water, a greater critical micelle concentration (CMC) as well as a lower average aggregation number. In aqueous solution, concentration-dependent micelles and vesicles can be formed in different ways. Bolaamphiphiles that exist because of a join on phenyl rings in a relatively rigid conformation, the possibility to produce fiber-like micelles, which are characterized by a high degree of helicity. Also in this case, the formation of stable, transparent gels are observed in aqueous solution.

Applications

It is possible to recreate the monolayer membranes of archaebacteria with bolas. After the covalent bonding of a hydrophilic group to a solid substrate to be used as a coating material for electrodes. By further chemical derivatization of the functional group remaining Bolas find application in processes that rely on molecular recognition.