Scared of Dropping the Soap? Worry No More.

by Katie Pratt

I realize that my audience here at BenchFly probably doesn’t contain a large number of prisoners, but I never claimed to cater to the majority. Also, you never know when you might end up incarcerated (wrongfully, obviously), so having a few science-y tricks up your sleeve is not a bad idea. And while this may not be a recipe for breaking out by dissolving the bars to your cell, it could make life on the inside a little better.

MAGNETIC SOAP!

If you drop that soap, all you’d need is a secret magnet and whoooosh! You wouldn’t have to bend over to pick it up!! Amazing, right?

Now, while researchers at Bristol University (my alma mater) are claiming that they developed their magnetic soap to deal with oil spills, my guess is that they are already selling the stuff on the black market. I could be wrong, though, so I will continue telling you about the soap as if they were solely concerned with conservation.

Julian Eastoe’s lab has been working on ways to control the activity of soaps for some time; in particular he has focused on finding ways to selectively destroy them. But a new soap developed in his lab, made by dissolving iron in ______- or ______-based soaps found in commercial detergents, allows for the selective removal of soap/oil mixtures from an aqueous environment.

The use of soaps in oil-spill cleanup is generally frowned upon. Despite the ability of surfactants to disrupt slicks, soap is itself damaging to the environment. It’s kind of analogous to using a predatory animal to wipe out a problematic invasive species. You end up with twice the problem you had in the first place, with the predator munching on native as well as invasive species. But what if the predator could be easily removed after eating a bunch of undesirables?

Seems like an idea that should’ve been figured out years ago, right? After all, we’ve known about magnetism and detergents and the behavior of metal ions in the vicinity of chlorides and bromides. The problem lies in the fact that soaps and oils interact to form little balls called micelles. Micelles are organized so that the parts of the fats and soaps that can happily hang out with water molecules face outwards (the hydrophilic bits) and the less cooperative (more hydrophobic) parts are contained within the ball. The detergent molecules and the oil molecules are able to move around within the micelle, which means that by applying a magnetic field you might expect the magnetic soap to leave the micelle, leaving behind a droplet of pure oil.

Now, as you know, I am a biologist, so I’m going to leave the physics of this next part for you to read in the paper if you are so inclined, but here’s my best attempt: The way I picture it is that these new micelles are super-tiny, and therefore when the magnetic field is applied the detergent molecules are not selectively ripped out. They are also stable enough that they can be pulled through an aqueous solution despite opposing water tension, thus making this magnetic soap and ideal substance for oil-spill cleaning operations. Makes sense to me anyway.

But you know what makes more sense? Manufacturing an actual bar of magnetic soap. Seriously, Brown et al. If you really haven’t thought of this yet, you could make some serious mullah if you did. Just sayin’.

Katie Pratt is a graduate student in Molecular Biology at Brown University. She has a passion for science communication, and in an attempt to bring hardcore biology and medicine to everyone, she blogs jargon-free at www.katiephd.com. Follow her escapades in the lab and online on Twitter.

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