Efficient mass transport under continuous and discontinuous graphitic confinement
Event details
| Date | 15.09.2016 |
| Hour | 16:00 › 17:00 |
| Speaker |
Prof. Hyung Gyu Park Department of Mechanical and Process Engineering, ETH Zurich |
| Location | |
| Category | Conferences - Seminars |
Efficient mass transport inside and across nanoscale graphitic surfaces such as carbon nanotubes and graphene, respectively, forms the basis of aqueous "carbon nanofluidic" phenomena for which there are numerous applications in energy and clean technologies. These unique phenomena of nanoscale mass transport has been actively pioneered, and still many questions remain unanswered such as "how fast is fast ?" In this talk, we will first review briefly the nanofluidics of fast water transport in carbon nanotubes and across graphene. Following, we will present our story of water transport measured under these graphitic nanoconfinements. A new scaling for comparing flow enhancement factors in carbon nanotubes will be proposed and discussed. This scaling can reconcile the apparent disagreement between simulations and experiments about how fast water can flow in carbon nanotubes.
Nearly frictionless flows established in carbon nanotubes lead to a question of ultimate permeation speed if one recognizes that having a friction-minimized pore could be equivalent to having no pore wall but only openings. To address this question, graphene serves as a material of choice for its great mechanical strength. We designed and manufactured a porous graphene membrane by direct physical perforation (focused ion beam milling) of freestanding double-layer graphene. When driven by pressure, the values of water permeance across this 2D membrane exceed that of any membrane material of the similar pore sizes and approach Sampson's formula - a theorectical prediction of the ultimate rate of a pressurized flow across a 2D disk
Nearly frictionless flows established in carbon nanotubes lead to a question of ultimate permeation speed if one recognizes that having a friction-minimized pore could be equivalent to having no pore wall but only openings. To address this question, graphene serves as a material of choice for its great mechanical strength. We designed and manufactured a porous graphene membrane by direct physical perforation (focused ion beam milling) of freestanding double-layer graphene. When driven by pressure, the values of water permeance across this 2D membrane exceed that of any membrane material of the similar pore sizes and approach Sampson's formula - a theorectical prediction of the ultimate rate of a pressurized flow across a 2D disk
Practical information
- General public
- Free
Organizer
- Prof. Kumar Varoon Agrawal
Contact
- Evelyn Ludi