Publication details
The Orientation and Charge of Water at the Hydrophobic Oil Droplet-Water Interface
| Authors | |
|---|---|
| Year of publication | 2011 |
| Type | Article in Periodical |
| Magazine / Source | Journal of the American Chemical Society |
| MU Faculty or unit | |
| Citation | |
| Web | http://dx.doi.org/10.1021/ja202081x |
| Doi | http://dx.doi.org/10.1021/ja202081x |
| Field | Biophysics |
| Keywords | SUM-FREQUENCY GENERATION; 2ND-HARMONIC GENERATION; AQUEOUS-SOLUTIONS; LIQUID WATER; VIBRATIONAL SPECTROSCOPY; MOLECULAR-DYNAMICS; HYDRATED PROTON; HYDROXIDE IONS; NEAT WATER; IN-WATER |
| Attached files | |
| Description | We established the charge and structure of the oil/water interface by combining zeta-potential measurements, sum frequency scattering (SFS) and molecular dynamics simulations. The SFS experiments show that the orientation of water molecules can be followed on the oil droplet/water interface. The average water orientation on a neat oil droplet/water interface is the same as the water orientation on a negatively charged interface. pH dependent experiments show, however, that there is no sign of selective adsorption of hydroxide ions. Molecular dynamics simulations, both with and without intermolecular charge transfer, show that the balance of accepting and donating hydrogen bonds is broken in the interfacial layer, leading to surface charging. This can account for the negative surface charge that is found in experiments. |