Graphene: The Fancy Ingredient for Your Fancy, Moderately Engineered Dishes
Foreword
Yes, I know that the title is ridiculous; no, I couldn’t think of a better analogy for what we’re going to talk about today: dispersion, aka mixing, aka “the bane of my existence when I make macrons.” Throughout today’s article, I’m going to be using baking analogies so please have at least a granola bar or something before starting. Personally, I get easily distracted when I get hangry.
Dispersion: One of the Three
If you got a chance to read the article from last week, I ended it on the fact that even though graphene is amazing and we should have it in everything, it has problems. The problem we’re going to dive into today is (SPOILERS) proper dispersion. Dispersion is just a fancy term used in the incredibly old composite industry for “mixing.” Whatever you do in your life, you mix things together all the time: Old Fashions, lattes, chocolate chip pancakes, baby formula, you name it. We all in some way are looking for a smooth, even mix in things we use every day. Now think back on a time where it didn’t mix well and how bad that went.
Separated latte with the shot on the top? I asked for a delicious caffeinated milk drink, not the physical embodiment of chaotic evil.
Milkshake sat too long and now has random pockets of pure milk? That’s a milk float, you psychopath.
Barely shook the bottle to mix the baby formula at 2:00 am? Congratulations, that nipple is going to clog non-stop, turning your precious newborn into a handheld car alarm.
You get the point.
How Does This Tie to Graphene?
In the same way that your milkshake settled out or how if you undermix flour in your cakes/cookies, it could severely impact your experience. Graphene is great if you can get it to mix just right, at just the right loading. Problem is, if you under mix it, you create weak points; points where your part is going to break before you can even see any benefits. These under mixed points are called “agglomerates.” These same agglomerates can also form even if you do everything right. It’s very frustrating. Like how the baby formula agglomerates form “weak spots” in the flow of your kid’s late-night dinner, it can cause major problems.
Dispersion Techniques, and Why They Don’t Work
There are currently three mixing techniques for graphene in use today: high shear (think milkshakes), three roll mill (essentially baking pins with 0.0000001 m gaps that crush), and ultrasonication (think at-home ring cleaners). These three have various advantages/disadvantages but to sum it up: shear mixing doesn’t mix enough in most cases; three roll milling is expensive and not scalable; and ultrasonication is so highly technical that nobody wants to deal with it, not to mention it’s overkill.
So why are these the only three? Because these methods are the only scalable options that can get you about 80% of the way there to unlocking the potential. How do we push it that extra 20% though?
Graphene Alone Isn’t Enough
This is where modifications come in, or what we like to call “functionalizations” in nerd speak. From graphene, you can put it through a couple of different processes to make it graphene oxide, which makes this material more compatible. Much like how you can get different flours that can do different things for you cakes depending on how the flours are processed. Once you have graphene oxide, you can do all sorts of wild things with it. For instance: if you leave a tad bit of sulfur on the graphene oxide during production, you have a product that can remain suspended in the mix almost indefinitely. If you slap an amine on there, you can have such a large spacing between the graphene platelets that your working surface area just went up 5x, meaning that the agglomerate that gave you catastrophic weak points just turned into your best friend by providing a massive increase in bonding points with very little effort. Now if you bring more intricate ingredients into the mix (baking soda/epoxides, lemon zest/PVP), you get something that reactively pushes against itself while providing the same insane increases with the same insanely low concentrations. These small and tasty additions allow graphene-based additives to be incorporated using highly scalable, low-end tech that anyone in their garage can do it.
It’s like when Gordon Ramsey uses saffron. He sometimes buys the cheap stuff but has to use a bird’s nest of it to get the flavor, but when he buys the authentic saffron that has been cared for, a little goes a long way to make a delicious dish.
Enough Chit Chat
What do you think we should do to enable the next material evolution? We’re in the lab right now working on some crazy cool stuff, but none of that matters if you don’t know how to use it, let alone if you can’t afford it. In the next article, we’re going to be covering price, and how we can all come together to learn and push for something so desperately needed in the world of materials.
