Teflon mark II to weather the storm in space
If you think the weather at your place is bad there’s no way it can compare with “space weather.” The International Space Station (ISS), which travels at about 27,700 kph (17,212 mph), is exposed to extreme levels of ultraviolet radiation and temperatures ranging from -40 to 60 degrees Celsius (-40 to 140 degrees Fahrenheit). These extreme conditions might not make for great holiday weather, but it does provide a good way to test the performance of new nanomaterials. That’s why samples of new nanocomposites - including an improved form of Teflon - will be mounted onto the ISS’s outer hull in a Passive Experiment Carrier (PEC), and exposed to the rigors of outer space.
It’s a common myth that polytetrafluoroethylene (PTFE), also known as Teflon, was the result of the space program. That may not be true, but the development of a stronger, more durable PTFE could result from the upcoming tests. A new wear-resistant, low-friction nanocomposite, created by mixing nanoscale alumina particles with PTFE has already proven to have a wear rate four times of magnitude lower than pure PTFE in a laboratory setting. The small amount of additive was also found to reduce wear without affecting the PTFE’s coefficient of friction.
According to its creators, the gained benefit of the new material is the difference between PTFE that can survive sliding along a surface for a few kilometers before wearing away, and a nanocomposite that could slide across a surface for more than 100,000 kilometers before wearing away. PTFE is often used to coat the surface of moving parts in different devices so the less friction on the surface of these moving parts, the less energy is required to move the parts.
The nanocomposite, which was developed at Rensselaer Polytechnic Institute, will be mounted on a tribometer, an instrument that measures the friction of a material’s surface. A control sample of the material, protected in a vacuum chamber in the PEC, will also be tested. The apparatus will send data in real-time to the ISS laboratory, which in turn will be forwarded to the research team.
During the loading of the tribometers into the PEC for space travel, an opportunity arose to also test the conductivity of carbon nanotube-filled polyamideimide and liquid crystalline polymers as a function of space exposure. This last minute opportunity meant that the conductive composites to be tested had to be developed in less than a week.
The experimental nanomaterials will be aboard the Space Shuttle Atlantic when it blasts off on November 16 on its way to the ISS.