Aerogel Can Now be Formed From Waste Paper
As previously reported on by Interesting Engineering, airloys and aerogels are proving to be the future of super-materials. In recent developments, scientists can now make the incredibly light solid out of cellulose fibers from recycled paper, making it biodegradable. Typically, aerogels and airloys are expensive to make due to their usual composition of silica gel and the process required to create the solid. This new method offers up a cheap, green alternative to the aerogel industry, possibly bringing the material's usefulness to the next level.
The process to make the new aerogel is surprisingly simple, involving the breakdown of paper shreds into cellulose using water, developed by the National University of Singapore. Once broken down, water and polymer resin is added to begin forming the shape and rigidity of the solid. Water is then extracted from the mix using a high-frequency sound machine. From this point, the material is subjected to freezing for 24 hours, then air-drying, with the process finishing with curing in an oven at 114 °C for 3 hours.
This process results in a cellulose-based aerogel that is 98.2 % air, yet still flexible and super insulative. A chemical coating can also be applied to make the material hydrophobic.
One possible application of the new material is cleaning up oil spills. The porous solid can soak up as much as 90% of its dry weight in crude oil without a drop of water due to its hydrophobic coating. However, 99% of the absorbed oil can be rung out, allowing for reuse in the cleaning process.
Among other industries, the product could be used as super-thin building insulation that also is moisture resistant and can hold load. If during the production it is not chemically coated to make it hydrophobic, the cellulose aerogel becomes extremely hydrophilic (water-absorbing) and can be used in diapers or hygiene products.
Unfortunately, it is unclear when the material will be available to consumers due to the recency of the discovery. This green, economical and useful material could reshape the practicality of the aerogel industry. While super materials still have a long way to go before they are cheap enough to build everything with, the future is drawing near.