Waste tires are are a major pain to recycle and usually end up in landfills or being burned for fuel/heat. They are especially popular with the poor because they take a while to burn and thus give heat for a longer duration. Unfortunately, the process is also very polluting and the smoke from these fires is especially bad for the environment (and for the folks breathing it in). However, there are not many uses for these tires at scale that are not more polluting, but that changes now. Thanks to research by Rice researchers, we now have a way to convert waste rubber into turbostratic graphene, which can be employed to strengthen concrete.
Most conventional production processes for graphene are time-consuming, solvent-intensive, and energetically demanding. To circumvent these limitations for mass production, flash Joule heating (FJH) has been shown to be an effective method to synthesize graphene. Here, methods for optimizing production of graphene from rubber waste feedstocks are shown. Through careful control of system parameters, such as pulse voltage and pulse time, turbostratic flash graphene (tFG) can be produced from rubber waste. It is characterized by Raman spectroscopy, X-ray diffraction and thermogravimetric analysis. The resulting tFG can be easily exfoliated and dispersed into various solvents because of its turbostratic arrangement. Addition of tFG into Portland cement results in a significant increase in the compressive strength of the composite. From a materials perspective, FJH offers a facile and inexpensive method for producing high quality tFG from rubber waste materials, which would otherwise be disposed of in landfills or burned for fuel. FJH allows for upcycling of low-value rubber waste into high-value carbon nanomaterials for use as reinforcing additives.
The researchers estimate that the conversion process’s electricity would cost about $100 per ton of starting carbon. It is great that more people are focusing on alternate uses / conversion of these ‘unusable’ items to more useable stuff.
More details are available here: Flash graphene from rubber waste
– Suramya