Carbon nanotube sponge can potentially clean up oil spills
A carbon nanotube sponge that can
soak up oil in water with unparalleled efficiency has been developed with help
from simulations performed at the Oak Ridge National Laboratory.
Carbon nanotubes, which consist of atom-thick sheets of carbon rolled into cylinders, have captured scientific attention in recent decades because of their high strength, potential high conductivity and light weight. But producing nanotubes in bulk for specialised applications was often limited by difficulties in controlling the growth process as well as dispersing and sorting the produced nanotubes.
ORNL’s Bobby Sumpter was part of the research team that set out to grow large clumps of nanotubes by selectively substituting boron into pure carbon, to understand how the addition of boron would affect the carbon nanotube structure.
“Any time you put a different atom inside the hexagonal carbon lattice, which is a chicken wire-like network, you disrupt that network because those atoms don’t necessarily want to be part of the chicken wire structure,” Sumpter said.
Simulations and lab experiments showed that the addition of boron atoms encouraged the formation of so-called “elbow” junctions that help the nanotubes grow into a 3D network. The team’s results are published in Nature Scientific Reports.
Further experiments showed the material is extremely efficient at absorbing oil from seawater because it attracts oil and repels water.
“It loves carbon because it is primarily carbon,” Sumpter said. “Depending on the density of oil to water content and the density of the sponge network, it will absorb up to 100 times its weight in oil.”
“You can reuse the material over and over again because it’s so robust,” he said. “Burning it does not substantially decrease its ability to absorb oil, and squeezing it like a sponge doesn’t damage it either.”
Carbon nanotubes, which consist of atom-thick sheets of carbon rolled into cylinders, have captured scientific attention in recent decades because of their high strength, potential high conductivity and light weight. But producing nanotubes in bulk for specialised applications was often limited by difficulties in controlling the growth process as well as dispersing and sorting the produced nanotubes.
ORNL’s Bobby Sumpter was part of the research team that set out to grow large clumps of nanotubes by selectively substituting boron into pure carbon, to understand how the addition of boron would affect the carbon nanotube structure.
“Any time you put a different atom inside the hexagonal carbon lattice, which is a chicken wire-like network, you disrupt that network because those atoms don’t necessarily want to be part of the chicken wire structure,” Sumpter said.
Simulations and lab experiments showed that the addition of boron atoms encouraged the formation of so-called “elbow” junctions that help the nanotubes grow into a 3D network. The team’s results are published in Nature Scientific Reports.
Further experiments showed the material is extremely efficient at absorbing oil from seawater because it attracts oil and repels water.
“It loves carbon because it is primarily carbon,” Sumpter said. “Depending on the density of oil to water content and the density of the sponge network, it will absorb up to 100 times its weight in oil.”
“You can reuse the material over and over again because it’s so robust,” he said. “Burning it does not substantially decrease its ability to absorb oil, and squeezing it like a sponge doesn’t damage it either.”
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