An incredibly light new material that can reduce aircraft engine noise and improve passenger comfort has been developed. The graphene oxide-polyvinyl alcohol aerogel weighs 2.1 kg per cubic meter, making it the lightest sound insulation ever manufactured. It could be used as insulation within aircraft engines to reduce noise by up to 16 decibels — reducing the 105-decibel roar of a jet engine taking off to a sound closer to that of a hairdryer.
The aerogel’s meringue-like structure makes it extremely light, meaning it could act as an insulator within aircraft engine nacelles with almost no increase in overall weight. The material is currently being further optimized to offer improved heat dissipation, offering benefits to fuel efficiency and safety. The material could be applied in a number of ways, initially in aerospace but potentially in many other fields such as automotive and marine transport as well as in building and construction.
The extremely low density was achieved by using a liquid combination of graphene oxide and a polymer that are formed with whipped air bubbles and freeze casted. The technique can be compared with whipping egg whites to create meringue, which is solid but contains a lot of air, so there is no weight or efficiency penalty to achieve big improvements in comfort and noise.
Although the team’s initial focus is working with partners in aerospace to test the material as a sound insulator in airplane engines, it could also be used to create panels in helicopters or car engines.