
Molecular models of nanotube ice produced by engineers at Rice University show how forces inside a carbon nanotube at left and a boron nitride nanotube at right pressure water molecules into taking on the shape of a square tube. The phenomenon is dependent upon the diameter of the nanotube. Courtesy of the Multiscale Materials Laboratory
Rice engineers show how water molecules square up in nanotubes
Here’s one way to fit a square peg into a round hole.
First, according to Rice University engineers, get a nanotube hole. Then insert water. If the nanotube is just the right width, the water molecules will align into a square rod.
Rice materials scientist Rouzbeh Shahsavari and his team used molecular models to demonstrate their theory that weak van der Waals forces between the inner surface of the nanotube and the water molecules are strong enough to snap the oxygen and hydrogen atoms into place.
Shahsavari referred to the contents as two-dimensional “ice,” because the molecules freeze regardless of the temperature. He said the research provides valuable insight on ways to leverage atomic interactions between nanotubes and water molecules to fabricate nanochannels and energy-storing nanocapacitors.
A paper on the research appears in the American Chemical Society journal Langmuir.
Shahsavari and his colleagues built molecular models of carbon and boron nitride nanotubes with adjustable widths. They discovered boron nitride is best at constraining the shape of water when the nanotubes are 10.5 angstroms wide. (One angstrom is one hundred-millionth of a centimeter.)
The researchers already knew that hydrogen atoms in tightly confined water take on interesting structural properties. Recent experiments by other labs showed strong evidence for the formation of nanotube ice and prompted the researchers to build density functional theory models to analyze the forces responsible.
Shahsavari’s team modeled water molecules, which are about 3 angstroms wide, inside carbon and boron nitride nanotubes of various chiralities (the angles of their atomic lattices) and between 8 and 12 angstroms in diameter. They discovered that nanotubes in the middle diameters had the most impact on the balance between molecular interactions and van der Waals pressure that prompted the transition from a square water tube to ice.
“If the nanotube is too small and you can only fit one water molecule, you can’t judge much,” Shahsavari said. “If it’s too large, the water keeps its amorphous shape. But at about 8 angstroms, the nanotubes’ van der Waals force starts to push water molecules into organized square shapes.”
He said the strongest interactions were found in boron nitride nanotubes due to the particular polarization of their atoms.
Shahsavari said nanotube ice could find use in molecular machines or as nanoscale capillaries, or foster ways to deliver a few molecules of water or sequestered drugs to targeted cells, like a nanoscale syringe.
Learn more: Nanotubes change the shape of water
The Latest on: Nanotubes
via Google News
The Latest on: Nanotubes
- Medical X-ray Generators Market To Reach USD 2.27 Billion | SWOT Analysis and Competitive Landscape By 2027on January 13, 2021 at 5:04 am
Technological advances, implementation of carbon nanotubes for accurate diagnosis, easy setup in low-density material are some factors boosting the ...
- Carbon Nanotubes-Based Self-Perceptive Soft Actuator for Underwater Sensingon January 8, 2021 at 7:57 pm
The research has been reported in the journal Nano Energy. The team created a morphable, flexible and conductive film made by embedding conductive carbon nanotubes (CNTs) film between two expandable ...
- Graphene Nanotubes Make Polyamide Paintableon January 5, 2021 at 4:00 pm
Modification of plastics with graphene nanotubes provides impressive results in anti-friction and anti-wear coatings, as well as exterior parts painted using the electrostatic painting method. R&P ...
- Carbon nanotubes begin to gain commercial tractionon January 5, 2021 at 4:00 pm
Carbon nanotubes (CNTs) have been touted as a wonder material for over a decade, but have disappointed commercially, suffering from overcapacity and lack of adoption according to a recent blog posting ...
- Copper + Carbon Nanotubes Yield Lower-Resistivity, Higher-Capacity Conductorson January 5, 2021 at 9:41 am
Steps taken to enhance copper conductivity by adding carbon nanotubes. Test results for conductivity, current-carrying capacity, and tensile strength. We know that copper (Cu) fortunately combines ...
- No Man's Sky Bases: How to build a Base Computer, Construction Research Unit and Base Teleport Moduleon January 4, 2021 at 4:00 pm
To create this the Terrain Manipulator you need: 2 Carbon Nanotubes 2 Di-hydrogen Jelly You should already know how to make these materials as they were important parts of repairing your ship.
- NIOSH Science Blog Reports on Recent Article Concerning Carbon Nanotubes and Nanofibers Used or Produced in U.S. Facilitieson January 4, 2021 at 4:00 pm
On January 5, 2021, the National Institute for Occupational Safety and Health (NIOSH) posted a Science Blog item entitled “Understanding the Broad Class of Carbon Nanotubes and Nanofibers (CNT/F ...
- Black Plastics Can Be Repurposed to Create Carbon Nanotubeson January 3, 2021 at 4:01 pm
Researchers have found a way to reuse black plastics and repurpose carbon materials from them into carbon nanotubes, which are valuable for a range of energy-related applications. (Image source: ...
- RISC-V Uses Carbon Nanotubeson January 2, 2021 at 4:00 pm
In a recent article in Nature, you can find the details of a RISC-V CPU built using carbon nanotubes. Of course, Nature is a pricey proposition, but you can probably find the paper by its DOI ...
via Bing News