Fourier transform infrared spectroscopy was applied to an examination of the phase transition behavior of aqueous bilayer membranes of double-chain ammonium amphiphiles. Large spectral changes were observed at the respective gel-to-liquid crystal phase transitions (Tc) of the bilayers. The frequency change in the antisymmetric CH2 stretching band indicated formation of the gauche conformation at Tc. The ester groups became either hydrated or disordered in the liquid crystalline state, but the amide units remained strongly associated. It is concluded that intermolecular hydrogen bonding is not necessarily weakened at Tc, although the molecular packing is loosened.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry