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| Type |
Poster Presentation |
| Area |
Physical Chemistry |
| Room No. |
Exhibition Hall 2+3 |
| Time |
10월 20일 (금요일) 13:00~14:30 |
| Code |
PHYS.P-89 |
| Subject |
The Surface of Acidic and Basic Water |
| Authors |
MdAlMamunur Rashid, Cheol Ho Choi*
Department of Chemistry, Kyungpook National University, Korea
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| Abstract |
Controversies on the acid-base properties of water surface were theoretically addressed with the help of large scale quantum mechanical molecular dynamics simulations (QMMD) on the water surface model systems with excess hydroniums or hydroxides. It was revealed that thermodynamic surface structures of these ions strongly depend on their surface location and dipole orientation. Hydronium is not only thermodynamically stable at the water surface, but it can also kinetically penetrate into the bulk via a fast proton transfer (PT) channel. On the other hand, the surface hydroxide is not as stable as hydronium. In addition, it can only take a slow molecular rotation as their major penetration mechanisms. Fast hydronium diffusion by PT establishes a wider kinetic depth distribution, while slow hydroxide is shallowly trapped below the outermost molecular layer (3~4 Å). On the basis of these, the enhanced acidity of water surface can be attributed in large part to the kinetic depth profile of the ion density in addition to static thermodynamic origin. Furthermore, the different depth profiles of the two ions may differently affect the surface-sensitive spectroscopic observations. |
| E-mail |
ndcmamun@gmail.com |
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120th General Meeting of the KCS