Science Buddies: "Ask an Expert"

For the Science Fair I am planning to create my own dual-action water filter. What I mean is that I am going to create a portable water filter that can remove all forms of pathogens, medical residues, even sewage as well as desalinize. I do not know of any water filters that purify and desalinize, it is usually one or the other. New studies have been conducted by MIT researchers on graphene and how it is very useful in the desalinization process. The graphene comes in one atom thick sheets and is perforated to the correct size so that water molecules may pass through, but the salt ions are blocked and stay on one side of the graphene. The inspiration for my filter is the LifeSaver Bottle by Michael Pritchard. It looks like a regular water bottle with a high end filter inside. I want to make something similar to that, but better.
My problem is that I want to purchase a graphene sheet, but when I researched where I could purchase some, there were ten different kinds and they cost upwards of eight hundred dollars. I need help figuring out which type of graphene I need to purchase. I am not yet sure how much graphene I would need, but if I simply knew what kind I need it would be so helpful. Please help
-kellycg95

Hello and welcome to the forums!

While I understand your desire to go right to making a product like the "LifeSaver", usually science progresses from the proof of concept to the finished product over time.
I'm sure you've read the MIT paper, but have you also researched what Lockheed Martin is doing? The reason I ask is that in the article I read, it says this about the graphene used to filter water:

thin carbon membranes with regular holes about a nanometer in size

.

I can find graphene for sale on the Internet, but both MIT and LM say that producing sheets of graphene with regular nanopores is very difficult. I don't know if you can find any available. Have you tried contacting researchers in your area to see about access to their labs and equipment?

If you can't find graphene, can you work on a proof of concept with other materials? Even this approach would benefit from a well outfitted lab.

And finally, if you do find some nanopore graphine, please be very careful when you handle it. A while ago there were news stories about how graphene flakes, when inhaled, might cause lung cancer the same way that asbestos particles do. While this may or may not be true, I would still be very careful in handling the material.

Let us know what you do!
Keith

Hi kelly,

Keith gave some great information already, and I found the same thing he has already gave you - Lockheed Martin has patented this technology for walter filtration and the prototype is not yet available for commercial review. MAYBE if you conteacted them, they would have further advice for you, or a sample to work with, but it is also possible (maybe probable) they won't assist you in any work in this area.

http://www.lockheedmartin.com/content/d ... asheet.pdf
http://www.lockheedmartin.com/us/mst/fe ... water.html

If you really want to know what kind of graphene they used - you could try to do a patent search online.

Please let us know how else we can help you.

Tonya