This graphene-based aerogel is that the lightest sound insulation material ever manufactured, espacially for jet engine say researchers at the University of Bath, who have demonstrated its ability to damp down noise by up to 16 decibels despite weighing just 2.1 kg per cubic-meter (0.13 lb per cubic foot).
You might not think weight is that much of an element with acoustic foams, but to place this aerogel’s density in context, compare it to a standard polyester urethane sound absorber like Kinetics KUA, which was “developed to soak up maximum acoustical energy using minimum weight and thickness” with a density of 32 kg/m3 (2 lb/ft3). So during a given application, this new “graphene oxide-polyvinyl alcohol aerogel,” squeezed into a Nomex honeycomb, would weigh but one-fifteenth of the same traditional acoustic foam installation.
Nowhere is weight so critical as in aerospace, and therefore the Bath team has identified engine nacelle insulation as a key potential marketplace for the technology, putting forth the instance that it could potentially reduce the cabin noise of a jet airliner from the present 105-dB roar to something closer to a 95-dB hairdryer.
“This is clearly a really exciting material that would be applied in number of the way – initially in aerospace but potentially in many other fields like automotive and marine transport, also as in building and construction,” says Professor Michele Meo, who led the research. “We managed to create such a particularly low-density by employing a liquid combination of graphene oxide and a polymer, which are formed with whipped air bubbles and freeze-casted. On a really basic level, the technique are often compared with whipping egg whites to make meringues – it’s solid but contains tons of air, so there’s no weight or efficiency penalty to get big improvements in comfort and noise.”
In their paper, the researchers say they believe the aerogel having other useful properties, including fire resistance and electromagnetic shielding, and there is also the potential to develop it further to optimize its cooling capabilities, which might be very handy in engine insulation. The team says it might be commercialized and in use within 18 months.
The research published in the journal Nature Scientific Reports.