The good heat is what keeps you warm in the cold; the bad heat is what melts your computer’s motherboard. All equipment generates heat and engineers, industrial designers, and others spend a fair chunk of time trying to minimize or remove the amount of ‘bad’ heat that is generated. Researchers at Rice University have developed an oil sprinkled with nanoparticles that could help with dissipating ‘bad’ heat in at least one industry sector. From the Feb. 1, 2012 news item on Nanowerk,
Rice University scientists have created a nano-infused oil that could greatly enhance the ability of devices as large as electrical transformers and as small as microelectronic components to shed excess heat.
Research in the lab of Rice materials scientist Pulickel Ajayan, which appears in the American Chemical Society journal ACS Nano (“Electrically Insulating Thermal Nano-Oils Using 2D Fillers”), could raise the efficiency of such transformer oils by as much as 80 percent in a way that is both cost-effective and environmentally friendly.
The Rice team headed by lead authors Jaime Taha-Tijerina, a graduate student, and postdoctoral researcher Tharangattu Narayanan focused their efforts on transformers for energy systems. Transformers are filled with mineral oils that cool and insulate the windings inside, which must remain separated from each other to keep voltage from leaking or shorting.
I was a little puzzled by that reference to “nano-infused oil”, thankfully an explanation follows,
The researchers discovered that a very tiny amount of hexagonal boron nitride (h-BN) particles, two-dimensional cousins to carbon-based graphene, suspended in standard transformer oils are highly efficient at removing heat from a system.
“We don’t need a large amount of h-BN,” Narayanan said. “We found that 0.1 weight percentage of h-BN in transformer oil enhances it by nearly 80 percent.” ”
And at 0.01 weight percentage, the enhancement was around 9 percent,” Taha-Tijerina said. “Even with a very low amount of material, we can enhance the fluids without compromising the electrically insulating properties.”
Narayanan said the h-BN particles, about 600 nanometers wide and up to five atomic layers thick, disperse well in oil and, unlike highly conductive graphene, are highly resistant to electricity. With help from co-author Matteo Pasquali, a Rice professor of chemical and biomolecular engineering and of chemistry, the team determined that the oil’s viscosity – another important quality – is minimally affected by the presence of the nanoparticle fillers.
I have previously mentioned hexagonal boron nitride in a Mar. 2, 2010 posting (scroll down) about Rice University researchers, h-BN combined with graphene, and a challenge to Moore’s law.