研究目的
To investigate the structure and dynamics of water at oppositely charged hydrophobic interfaces using two-dimensional heterodyne-detected vibrational sum frequency generation (2D HD-VSFG) spectroscopy.
研究成果
The 2D HD-VSFG study demonstrated that the sign of the interfacial charge significantly affects the structure and dynamics of water at hydrophobic interfaces. At the anionic TPB-/water interface, distinct π-hydrogen bonded OH groups were identified, in addition to usual hydrogen bonded OH groups, which were hidden in the steady-state spectrum. In contrast, the cationic TPA+/water interface only showed the presence of usual hydrogen bonded OH groups. The findings highlight the decisive role of the charge in governing the structure and dynamics of water molecules facing hydrophobic regions.
研究不足
The study's limitations include the time-resolution (~200 fs) of the present 2D HD-VSFG experiments, which may not directly detect ultrafast hydrogen-bond fluctuation (~60 fs). Additionally, the use of isotopically diluted water, while beneficial for suppressing vibrational couplings, may not fully represent the natural state of water in all environments.
