Japanese scientists have shown how cross-linked polymeric gels can help trap highly volatile liquid fuel molecules, thereby reducing their evaporation rate and preventing an explosion from happening.
According to the team from Tokyo’s Shibaura Institute of Technology (SIT), most liquid fuels possess a high energy density and this makes them essential for applications where chemical energy is converted into controlled motion, such as in rockets, gas turbines, boilers, and certain vehicle engines.
With their combustion characteristics and performance being both volatile and necessary, one needs to guarantee the safety and stability of these fuels when in use as well as during transport and storage.
This is easier said than done as liquid fuels evaporate quickly if given space, producing clouds of highly flammable gases that can cause catastrophic explosions or fire accidents.
Now a team of scientists led by professors Naoki Hosoya and Shingo Maeda from Shibaura Institute of Technology (SIT) and Tokyo Tech respectively, has shown how liquid fuels can be safely stored within polymeric gel networks.
As part of their research, the scientists analyzed the performance, advantages, and limitations of storing ethanol within a chemically cross-linked poly(N-isopropylacrylamide) (PNIPPAm) gel.
They created small spheres of PNIPAAm gel loaded with ethanol and placed them on an electronic scale to record how mass changed as ethanol vaporized.
What they found was that storing ethanol within the polymer gel completely suppressed the fuel’s tendency to rapidly vaporize.
“The polymeric gel contains innumerable three-dimensional polymer chains that are chemically cross-linked in a strong way. These chains bind the ethanol molecules through various physical interactions, limiting its evaporation in the process,” notes Hosoya.
The scientists also sought to examine the actual combustion characteristics of the ethanol in the polymeric gel network to see if they burnt efficiently.
Thanks to this, they were able to determine that the burning of the loaded PNIPAAm gel spheres consists of two phases: a phase dominated by pure ethanol burning, followed by a second phase dominated by the burning of the PNIPAAm polymer itself.
Image and content: Naoki Hosoya/Shibaura Institute of Technology
