The temperature-dependent conformational states of a monolayer film of ethylene glycol monododecyl ether (C12E1) at the air/water interface have been investigated using ellipsometry, surface tension, external reflection-absorption FTIR spectroscopy and two-dimensional infrared (2DIR) correlation analysis. The ellipticity coefficients and the entropy associated with C12E1 adsorption changed almost discontinuously at certain temperatures, which manifested the interfacial phase transitions. The phase transition and coexistence of two phases were further clarified using 2DIR correlation analysis with temperature perturbation. The asynchronous correlation maps revealed that both bands of asymmetric and symmetric C-H stretching vibration in one-dimensional IR were split into two components, which confirmed the coexistence of two phases at the interface.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Polymers and Plastics
- Colloid and Surface Chemistry
- Materials Chemistry