Helical aggregation of chiral amphoteric surfactants containing hydroxyl groups
1991; Elsevier BV; Volume: 58; Issue: 1-2 Linguagem: Inglês
10.1016/0166-6622(91)80193-r
ISSN1873-4340
Autores Tópico(s)Liquid Crystal Research Advancements
ResumoAbstract An amphiphilic associated dimer compound containing both a hydroxy group and an asymmetric carbon atom exists in fibrous helical aggregates in an organic solution, when observed under an electron microscope. l - N -(2-hydroxydedocyl)valine forms fibrous aggregates with a right-handed helicity, whilst those of the d -derivative have a left-handed twist. Chiral N -(2-hydroxydodecyl)tryptophan forms rod-like aggregates with no helicity. Further, as a similar example of the molecular dimer, N , N ′-bis[1-carbonyl- D (or L)-12-hydroxyoctadecyl] alkanediamine exhibits a fibrous twisted aggregate. Amphoteric surfactants (amino acid derivatives) containing a long alkyl group also have thermotropic liquid crystalline properties. Therefore, the −OH group in the 2-hydroxyalkyl chain plays an important role by enabling formation of an intermolecular hydrogen bond.
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