Facinating metal rings change multiple colours.

Edit: I had hunted down a YouTube upload of the Reddit video I'm about to describe, but that upload disappeared before this post even appeared, so I'm just linking to the Reddit original. I do warn you that the title of the subreddit contains a nsfw word. It's titled blackmagicf***ery. You have been warned. The above video is less thrilling and contains some pretty annoying music though it does show the same concept of titanium anodization.

I originally found it on one of Reddit's unfortunately-named subreddits. That link is here, but I'll avoid embedding from the Reddit source so the inappropriate subreddit title won't show up here. You have been warned.

It is exactly the same video, however the reddit version is in slightly higher resolution.

Not much to say here other than that this is a bit of a teaser for a video I'm posting later this week that explains how anodizing works...

...and the new fad deadly among teenagers that you need to know.

To adsorb or not to adsorb

 

Source - https://phys.org/news/2021-06-adsorb.html

Man, he looks like a fun guy at parties, eh?

"Hey, guys, I brought a bowl full of 3d printed phages! They can be party favors, no?"

"Sure, Ivan, just put them in the corner there next to the coats. And did you bring money for the pizza?"

"Sorry, I forgot with all the excitement about the phages. I'll get you next time."

Yeah, sure you will.

As the phys.org article says, "bacteriophages...are specialized viruses that can infect and kill bacteria without adverse effects on humans." 

In order for those phages to work, however, they have to be stored and then injected into the human body. "Unfortunately, despite beneficial treatment and numerous trials, the number of active bacteriophages in the solution for injection can drastically decrease, making the treatment ineffective."

The scientists in this study looked at how the properties of the container used to store the phage solutions affected the concentration of available phages. They found that the hydrophobicity of the polymer material of the container drastically affected that concentration as the phages adsorbed onto some container's surfaces rather than remaining available and in solution. Apparently the "aggregation of phages onto walls is mor [sic] profitable energetically than staying in solution."

As the study said, "[i]n case of sudden need...the choice of container for the phages seems to be trivial. However, as the study shows, such a factor has a tremendous impact on the number of active phages in the solution and, therefore, in determining successful therapy."

Who knew? The container matters?

Glass bakeware that shatters (December 2010) | Consumer Reports

How have I missed posting this in the blog? I've been using this video for a couple of years to explain that pyrex =/= Pyrex.

I would explain, but honestly, the Consumer Reports host up there does a great job explaining that consumer pyrex isn't the same as lab Pyrex and hasn't been for decades.

Tl;dr - don't take your pyrex casserole dish from the freezer to the oven or from the oven to the countertop.

PBF - Dick (webcomic)

From Perry Bible Fellowship - https://pbfcomics.com/comics/dick/

See, it's funny because...well, it's probably only funny in a really, really dark way.

There's this guy who seems to be captaining a whaling ship. We'll call him Ahab. 

He seems to have spotted something, a whale, we assume.

He takes a drink from the colorful bottle in his hand...then drinks from a series of very colorful, seemingly modern bottles.

We close by seeing the whale dead in an ocean littered with plastic waster.

See, it's funny because we're killing our ocean's life by polluting the water with plastics.

Get it?

As an aside, be warned that many other cartoons on PBF are less school-appropriate. Browse at your own risk. They are, however, often hilarious in very dark ways.

Fractionating column videos

Last spring - when the schools all went quarantine from Covid - we were just beginning our polymer unit in material science. 

So we went looking for videos and demonstrations that would 'teach' what we would have covered in class.

Among the better videos were these explaining how a fractionating column works to separate the various hydrocarbons found in crude oil.

Titanium - The Metal That Made The SR-71 Possible

 Hey there, Brian. Good to hear you again.

I recognize those material selection diagrams at 1:35. I've posted about similar diagrams before.

This video does a great job exploring the tradeoffs among strength, weight, cost, and properties in choosing a material. In this case, it's mostly about the tradeoffs guiding when we do - and don't - use titanium.

It also covers some of the concepts of chemical and electrolytic reduction around 5:00 - and states that we don't use either of the traditional processes to purify titanium. It's amazing that anybody ever figured out some of the more complicated metals processing...um...processes. They're so remarkably complicated.

We also get an application of accidental galvanic corrosion at 8:30 where the cadmium-plated tools were leaving trace amount of cadmium on the titanium.

Titanium really sounds like a pain in the tuchus to work with.

Piezoelectricity - why hitting crystals makes electricity

Heya, Steve. Good to see you back again.

The part of this video that I think I most appreciate is the actual look at the guts of a piezo electric safety lighter. I've used them for a long time and never quite been sure how they work on the inside.

I also appreciate Steve's comments on quarts 'healing crystals' around 1:40. "Don't know if you take it orally or..."

And then we get into the fact that piezoelectricity is dependent on the electronegativity differences in a quart crystal (admittedly simplified in Steve's peanut-butter-jar model). I'm totally duplicating this post for my chem blog because of that explanation.