Raman studies of cation–surfactant interactions in alkylpolyoxyethylene surfactant aqueous solutions

Abstract

Raman studies are reported of conformational change in an alkyl polyoxyethylene non-ionic surfactant associated with coordination to alkali and alkaline earth metal cations. This surfactant has a simpler mix of conformers (with TZT relatively unimportant) compared with non-ionic surfactants incorporating an aromatic ring in the bydrophobic head-group. This relatively simple conformational pattern facilitates the interpretation of the 868 cm-band assigned to a TGITGT (T, tram; G , gauche; G, gauche minus) for the 4 C H z C H z O C H z C H z~ polyoxyethylene sequence associated with surfactant-cation complexes. Counter anions such as halides appeared to have a negligible effect on complex formation.

Conformational Analysis of Nonionic Surfactants in Water by a Selective Monodeuteration Method. C−D Stretching Infrared Spectroscopy of α-Monodeuterododecyl-ω-hydroxytris(oxyethylene)s

“…By using these marker bands, detailed conformational analysis is possible even for complex systems. We have studied by Raman spectroscopy the molecular conformation of a series of C n E m surfactants ( n = 1−16 and m = 1−8) in the solid state and have clarified the relation between the conformation and the chain length. − Vibrational spectroscopy has been applied extensively to aqueous solutions of C n E m and other related surfactants. − In most of these studies, the molecular structure has been discussed in relation to the phase transitions in the surfactant−water systems. The phase and conformational transitions in lipids and biomembranes have also been studied by vibrational spectroscopy…”

“…[18][19][20][21] Vibrational spectroscopy has been applied extensively to aqueous solutions of C n E m and other related surfactants. [22][23][24][25][26][27][28][29][30][31][32][33][34] In most of these studies, the molecular structure has been discussed in relation to the phase transitions in the surfactant-water systems. The phase and conformational transitions in lipids and biomembranes have also been studied by vibrational spectroscopy.…”