What happens to nanoparticles in the environment?
What is a nanoparticle? What role do nanoparticles play in technology? Why is it important to be responsible when using them? Let’s find out more!
Tiny “nano” particles are found in many areas of our everyday lives, from cosmetics to electronics.
But what is a nanoparticle? First, it is really, really tiny. Nanoparticles are so small that you can fit 1,000 of them across a human hair.
Nanoparticles can help improve our manufactured products and technology, like batteries in our phones, computers, and electric cars. But how?
To answer that question, let’s do an experiment. Which do you think will dissolve faster in water: a whole bubbly antacid tablet, like Alka-Seltzer, or the same tablet that’s been crushed up?
If you answered the crushed tablet, you are correct! Although both tablets are the same amount of material, the crushed tablet is in smaller pieces, so it has a higher surface area.
Higher surface area increases the contact between the tablet and water. Smaller pieces have more surface area to perform reactions, so they dissolve faster and make more bubbles.
Like the crushed-up tablets, nanoparticles have a high surface area because they’re so small. This makes them more reactive than larger versions of the same materials.
The high reactivity of nanoparticles makes them awesome materials for phone batteries!
Nanoparticles found in phone batteries, like Lee here, are often made of compounds like lithium cobalt oxide.
Lee is made of layers with spaces big enough to store charged molecules called ions, such as lithium.
Giving and taking lithium ions from these layers is how batteries work, and this is the reaction that supplies your devices with power!
As a nanoparticle, Lee’s large surface area increases their reactivity, meaning they can quickly give and take lithium ions. This makes Lee a super battery material!
While Lee is great at their job in a battery, their amazing powers can become a problem, even dangerous, in the wrong environment.
For example, what happens to Lee if a broken phone ends up in a lake?
Lee has entered a new environment with plants, fish, and small creatures called microbes.
Because of their nano size, Lee is able to explore all parts of the environment, even places as small as living cells. Let’s find out how Lee’s super small size affects a fish!
A fish is covered by protective scales, but the gills it uses to breathe are exposed. The gills give Lee an entryway into the fish.
In the battery, Lee was great at giving and taking lithium ions, but Lee’s super ability as a nanoparticle wasn’t meant for other environments.
Inside the fish’s gills, Lee starts to give away all of their ions, both lithium and cobalt. So, how do cobalt ions affect the fish’s gill cells?
Cobalt is a heavy metal, like lead, and its ions can poison living creatures in the environment.
Lee and their cobalt ions can also produce free radicals that damage fish cells, particularly the DNA inside cells. (Free radicals are why people take antioxidants and eat “superfoods.”)
The cobalt ions and free radicals work together to damage the fish’s gill cells. This makes it harder for the fish to breathe, which can make the fish sick.
Fish aren’t the only creatures Lee might hurt. Lee can also interact with plants, bugs, and microbes, which all depend on one another to make a healthy ecosystem.
To protect all of these important creatures, it is our responsibility to make sure that Lee never enters the environment at all.
So what can we do when it’s time to dispose of devices with rechargeable lithium-ion batteries, like our phones? Don’t throw them in the trash!
If we recycle our batteries instead of throwing them into the garbage, Lee won’t end up in our lakes or rivers. In fact, they may even get another chance to be in a battery, which makes everyone happy!
- Use call2recycle to find locations in your area to dispose of Li ion batteries.
- Use battery manufacturer resources to properly dispose of batteries. For example, you could Google “Apple battery recycling.”
- Contact your local solid waste district.
If you’re interested in learning more about the sustainable use of nanoparticles in technology, check out our blog at sustainable-nano.com!
Remember, nanoparticles are safe and helpful when used responsibly!
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Miriam is the Director of Education, Outreach, and Diversity for the NSF Center for Sustainable Nanotechnology. She earned her BA in geology from Pomona College and her PhD in Speech-Language-Hearing Sciences from the University of Minnesota.
Mike is the Managing Director of the NSF Center for Sustainable Nanotechnology.
This material is based upon work supported by the National Science Foundation under the NSF Center for Sustainable Nanotechnology, grant number CHE-2001611.Learn more