A new study from researchers at the University of California, Berkeley, has found that carbon nanotubes have a love/hate relationship with water. On the one hand, they are hydrophobic, meaning that they repel water. On the other hand, they also have a strong attraction to hydrogen bonds, which are the bonds that hold water molecules together.
This love/hate relationship has a number of implications for the use of carbon nanotubes in water-based environments. For example, it means that carbon nanotubes can be used to create water-resistant materials. However, it also means that carbon nanotubes can be damaged by water.
The researchers found that the hydrophobic nature of carbon nanotubes is due to the presence of carbon-carbon bonds on their surface. These bonds are non-polar, meaning that they do not have a net electrical charge. As a result, they do not interact strongly with water molecules.
On the other hand, the attraction of carbon nanotubes to hydrogen bonds is due to the presence of oxygen atoms on their surface. These oxygen atoms are polar, meaning that they have a net electrical charge. As a result, they can form hydrogen bonds with water molecules.
The strength of the interaction between carbon nanotubes and water depends on the relative proportions of carbon and oxygen atoms on the nanotube surface. The more carbon atoms there are, the more hydrophobic the nanotube will be. The more oxygen atoms there are, the more hydrophilic the nanotube will be.
The researchers say that their findings could help to improve the design of carbon nanotubes for water-based applications. By understanding the interactions between carbon nanotubes and water, scientists can design nanotubes that are either more hydrophobic or more hydrophilic, depending on the desired application.
The study was published in the journal Nature Materials.
