Infrared Spectroscopy of Anionic, Cationic, and Zwitterionic Surfactants

Figure 8

Selected regions of the FTIR spectra for the HPS molecule. (a) C–H stretching vibrational features; (b) methylene scissoring vibration and asymmetric bending mode of the head (N(CH₃)₃) methyl group. (c) CH₂ wagging region; (d) sulfonate vibrational modes. The spectra refer to the HPS packing densities: 9.4×10¹⁵, 3.4×10¹⁶, 6.4×10¹⁶, 1.8×10¹⁷, and 5.4×10¹⁷ molecules cm⁻².

(a)

(b)

(c)

(d)