Magnetic soap

This video demonstrates a nifty advance in surfactant science: unfortunately I can't include it here, so you have to click on supporting information then the .mpg video file link to see it.

What is shown on the right, sticking to the metallic disk being lowered into the liquid, is magnetic soap. (On the left is normal, non-magnetic soap.) The little yellow blob that lifted with the magnet-on-a-stick through the clear liquid and then fell when the magnet was lifted right out of the liquid, is the soap itself.

Three different non-magnetic surfactants were made magnetic by reacting them with ferric chloride, a common industrial chemical.

A solution of ferric chloride by itself also reacts very slightly to magnets, but it finds most of its use as a coagulant, not as a soap.

Violent separation

In keeping with my original plan for this blog, I am now going to teach myself something new.

Here is something I have known about and occasionally seen since I was a kid, and know the name of, but hadn't seen it in operation and didn't actually know how it worked until I decided to write this post and figure it out:

It works exactly the same way as this thing, which I saw for the first time as an adult:

Recycling water

It may be something we don't like to think about, but one of the things the astronauts have to do while in orbit will be coming more and more to Earth. Fresh water is limited, and getting more so with time. Water conservation helps, but it may not be enough in the future.

Whether they are dependent on well water or surface water, many cities have to worry about having enough water to last through the dry season as the water levels drop. Water restrictions are common in some areas; where I grew up, part of the summer routine was that you couldn't water your lawn whenever you wanted, but only on certain days. Sometimes there was an outright ban on watering lawns if the river level was too low.

At the same time, the volume of water leaving a city's wastewater treatment plant is a substantial part of what the city brought in to start with, and grows with population more than the season.

As wastewater treatment technology improves, the sewage plant's discharge gets cleaner and cleaner, so why not use it as feed for our clean water treatment system?

Airplane-induced snow

An airplane made that hole.

Not by just flying through it and swirling the visible cloud out of the way, that makes a different pattern which doesn't last nearly as long.

It turns out that in certain conditions, airplanes can actually induce rain or snow in a localized region of a cloud, and the precipitation is what clears the hole - the water droplets that make up the cloud fall because of the airplane.

Happy new year

Well, I haven't been at this for a full year, but it's been an interesting seven months so far. I've definitely spent a lot more time keeping up with the science news by trying to post something every week. I'm also glad I didn't set out to try to post more than one a week!

I think I'll stick with the Monday post schedule, even if sometimes I have to post something light. I'm also going to try to do more chemistry type stuff; it surprised me how much time I spent outside of chemical engineering and related fields. I also want to do more posts calculating random things, because the ones I've done so far were a lot of fun for me.

Let's see how the next year goes...