Nano in H₂O

How graphene can be used in water filtration

If you’ve heard of graphene and its properties (if you haven’t, check out my article on it!), you should know of its amazing thermal properties, flexibility, and how lightweight it is. This allows graphene to be used for many conductivity-related things, such as batteries, solar panels, and even smartphones. One other bizarre thing it can be utilized in is actually water filtration!

Researchers at Brown University have discovered the filtration properties of graphene and how the 2-D nanomaterial can be used to separate water from harmful substances or particles. This innovation could potentially help make water cleaner and save the lives of people across the world.

Nanomaterials

Fullerene (structure on the left)

One of the things that makes graphene so ideal for water filtration is that it’s a nanomaterial, which means that it’s a nano-sized material that can be used for many things. Nanomaterials are usually measured by nanometers, with one nanometer being one-millionth of a millimeter.

As of right now, there isn’t an exact by-the-book definition of a nanomaterial, but examples of nanomaterials other than graphene that I highly recommend looking into include fullerenes, quantum dots, and silver nanoparticles.

Why Graphene?

The reason graphene in particular can be used for water filtration is because of how tightly bound graphene atoms are. Graphene atoms arrange themselves in a hexagonal shape, which contributes to the strength and flexibility of graphene. In fact, a sheet of graphene is literally an atom thick, making it practically 2-D. This makes the process just a bit quicker in the way that the water doesn’t have to go through a really long system of water filtration (although this does still take some time).

How It Works

The star material of the filter is — you guessed it — graphene! Making the graphene planar would take the water a lot longer to complete its travel through the sheets from start to finish, so the key here is to vertically align the orientation of the sheets perpendicular to the channels. The key to vertically aligning the sheets of graphene is to wrinkle the graphene sheets, which leads to the channels being aligned almost vertically.

After the channels are aligned, the final touches are added — covering the filter in epoxy and trimming away the tops and bottoms, further opening the channel.

As said before, the reason why graphene works so well for water filtration is because of the way the atoms are arranged. Not only do they arrange in a hexagonal shape, but the gaps between them are also incredibly small. This is the key factor in why this works so well.

Although this new graphene technology can truly be evolutional if further developed, there are cons and pros to the invention.

Pros & Cons

Cons

Starting off with the cons, the graphene filter does take a lot of time to filter water. As mentioned before, graphene is 2-D, but the sheets are stacked on top of one another to provide more thorough filtration. The water also has to travel across the entire surface of the graphene in the process of filtration, which means that this method of using graphene to filter water may take some time.

Graphene also does cost a bit of money. In the United States, graphene costs $100 per gram. This is an extremely high price tag, which makes it a bit difficult to consider how it could help third-world countries if it still isn’t affordable.

Although these downsides are a bit of a problem and do need to be considered, there are also upsides on how beneficial the technology could be!

Pros

Despite the price, graphene filters are environmentally friendly! They don’t require any sort of energy or electricity to get them to operate, which makes them a lot more desirable for third-world countries.

Speaking of third-world countries, these filters can also be portable! This means that water from a lake, sea, or really anywhere can be pumped into the filter and drank.

Overall, there are definitely some kinks that need to be worked out in this invention, but with further work, the pros can outweigh the cons. This truly has a ton of potential and can be an amazing resource of water for those who need it in the future.

Hi! I’m a TKS Innovator, and I’m really interested in all things biotech/med and nanotechnology!

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