EFFECT OF COMPLEMENTARY HYDROGEN-BONDING ADDITIVES IN SUBPHASE ON THESTRUCTURE AND PROPERTIES OF THE 2-AMINO-4,6-DIOCTADECYLAMINO-1,3,5-TRIAZINE AMPHIPHILE AT THE AIR-WATER-INTERFACE - STUDIES BY ULTRAVIOLET-VISIBLE ABSORPTION-SPECTROSCOPY AND BREWSTER-ANGLE MICROSCOPY
Q. Huo et al., EFFECT OF COMPLEMENTARY HYDROGEN-BONDING ADDITIVES IN SUBPHASE ON THESTRUCTURE AND PROPERTIES OF THE 2-AMINO-4,6-DIOCTADECYLAMINO-1,3,5-TRIAZINE AMPHIPHILE AT THE AIR-WATER-INTERFACE - STUDIES BY ULTRAVIOLET-VISIBLE ABSORPTION-SPECTROSCOPY AND BREWSTER-ANGLE MICROSCOPY, Langmuir, 14(8), 1998, pp. 2174-2186
The present work is focused on the effects of hydrogen bonding on the
2-D properties of aminotriazine amphiphile 1 (2C(18)TAZ) by incorporat
ing different complementary hydrogen bonding components in the subphas
e. The structural organization of 1 at the air-water interface in the
presence of barbituric acid (BA), barbital (BT), and cyanuric acid (CA
) was examined by surface pressure-area isotherm measurements, Ultravi
olet-visible (UV-vis) absorption spectroscopy, and Brewster angle micr
oscopy. UV-vis absorption spectra reveal that amphiphile 1 forms an ir
reversible monolayer at the air-water interface due to its ''auto asse
mbly''. The binding of BA molecules to a 2C(18)TAZ monolayer can be de
tected by UV spectra at BA subphase concentrations as low as 0.01 mM.
Different complementary hydrogen bonding additives in the subphase hav
e different effects on the monolayer structure and properties of 1, wh
ich are likely due to the different structures of hydrogen bonding add
itives at the air-water interface. The effects of organic solvents in
the subphase was also investigated. The strong solvating ability of di
methyl sulfoxide (DMSO) destroyed the hydrogen bonding network whereas
dioxane enhanced the hydrogen bonding between 1 and its hydrogen bond
ing complements.