Effect of a two-phase boundary in D2O/triethylamine solution: An 1H NMR study.

1 H NMR spectra were recorded in triethylamine (D 2 O/triethylamine) binary aqueous solution which had a lower critical point of the liquid–liquid phase transition. The spectra in the phase with predominant content of triethylamine molecules were found to get broaden inhomogeneously above the critical temperature. It is hypothesized that D 2 O/triethylamine system at 10 −3 ≤ (T–T c )/T c ≤ 10 −1 falls into the area of long-wave fluctuations of the order parameter. The revealed broadening can be attributed to the intermolecular interaction between triethylamine and water in the vicinity of the two-phase boundary. [ABSTRACT FROM AUTHOR]