Water in Carbon Nanotubes: The Peculiar Hydrogen Bond Network Revealed by Infrared Spectroscopy
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- 作者：Simona Dalla Bernardina ; Erwan Paineau ; Jean-Blaise Brubach ; Patrick Judeinstein ; Stéphan Rouzière ; Pascale Launois ; Pascale Roy
- 刊名：Journal of the American Chemical Society
- 出版年：2016
- 出版时间：August 24, 2016
- 年：2016
- 卷：138
- 期：33
- 页码：10437-10443
- 全文大小：461K
- 年卷期：0
- ISSN：1520-5126
文摘
A groundbreaking discovery in nanofluidics was the observation of the tremendously enhanced water permeability of carbon nanotubes, those iconic objects of nanosciences. The origin of this phenomenon is still a subject of controversy. One of the proposed explanations involves dramatic modifications of the H-bond network of nanoconfined water with respect to that of bulk water. Infrared spectroscopy is an ideal technique to follow modifications of this network through the inter- and intramolecular bonds of water molecules. Here we report the first infrared study of water uptake at controlled vapor pressure in single walled carbon nanotubes with diameters ranging from 0.7 to 2.1 nm. It reveals a predominant contribution of loose H bonds even for fully hydrated states, irrespective of the nanotube size. Our results show that, while the dominating loosely bond signature is attributed to a one-dimensional chain structure for small diameter nanotubes, this feature also results from a water layer with “free” OH (dangling) bonds facing the nanotube wall for larger diameter nanotubes. These experimental findings provide a solid reference for further modeling of water behavior in hydrophobic nanochannels.