Graphene has arrived at just the right time to meet the needs of nanotechnology. With extraordinary properties that have surprised researchers over the last two decades, it is very close to being the component of a multitude of objects and machines of the latest generation, from the structure of ultralight aircraft to high-capacity batteries.
Essayons de comprendre
With the same chemical composition as diamond and graphite (pure carbon), it has a single-layer lamellar structure with hexagonal cells. This structure gives it extraordinary mechanical and electrical properties, it is transparent, flexible, dozens of times lighter and stronger than a hypothetical steel sheet of the same thickness and can transport and store electrical charge with great efficiency.
This is not the first time that a material with extraordinary properties and the potential to become a universal panacea has appeared. In its time, plastic played this role and today we have a huge unsolved environmental problem. Will the same happen with graphene?
Risks of Graphene
Very little has been researched and published on the environmental risks of graphene. From the processes of obtaining it using strong oxidizers and reductants to its disposal as a waste material, both workers and the environment will be exposed to risks that are not clearly defined at this time.
A multidisciplinary group at Brown University found that graphene nanoparticles have very hard, jagged edges that can easily rupture lung cell membranes. The risk from inhalation and ingestion must be carefully considered. Read here.
Another group from Riverside’s Bourns College of Engineering (University of California) has studied the behavior of graphene oxide nanoparticles in water. They have found that their persistence and mobility depend on ionic charge and organic matter content. In hard water with very little organic load (groundwater) they are not very stable and tend to disappear, but in water with a higher organic matter content and less hard (surface water) the particles are much more stable and can remain in the current. Persistence and mobility in surface water are factors that aggravate the risk to animals and plants.
Considered irritating to eyes and skin, it is recommended to prevent inhalation and ingestion, but there is no official information on the toxicity and/or carcinogenic effects of graphene.