Karen Lise Krabbe: Gelled Glass

That's absolutely fascinating.

I've seen the reverse spherification technique of using sodium alginate and calcium chloride solutions to produce edible, gelled products (Kool Aid worms, gelled drink spheres, cocktail pods). Sometimes the calcium chloride is swapped out for calcium lactate because it's really the calcium ions that are necessary for the process.

But using that process to make gelled glass which can be shaped in ways that glass normally couldn't be shaped is pretty amazing. All respect to Karen Lise Krabbe for developing this technique. If you want to learn more, you can check out her ebook on the technique.

Magical liquid!

Most years, I give my students some freedom after the AP chemistry exam. There's still so much more chemistry to learn, but I've completed the required curriculum for the year, so we can explore a few cul de sacs of chemistry.

We've played Minecraft because they told me there was a bunch of actual chemistry involved - which turned out to be kind of true. There's certainly a whole bunch of material science involved.

I've also had them research chemistry programs as universities around the midwest, practice and perform a demonstration for my non-AP course, and honestly - write a blog post for my chemistry blog. 

Today's post, however, is about the time my students asked if they could just make slime. We make polyvinyl alcohol slime in first year chemistry, but they wanted to make glue (which I recognize is often PVA-based) slime. One of the students said she had a gallon of Elmer's school glue at home from her Covid lockdown slime days (apparently slime-making was a thing for many school-age students during Covid lockdown?)

In discussing what they could bring in, other students in the class offered to provide shaving cream (apparently to make 'cloud' slime - a fluffy variation), small fruit-shaped slime charms, glitter, and non-staining food coloring. I, generous sort that I am, offered my leftover borax solution from the crystal making experiment early in our matsci curriculum. It's a little more than the 4% concentration called for in most slime recipes, but it's close enough.

One of the students asked me if the borax solution took the place of the activator. I'd never heard of an 'activator' solution before, so I started looking around online.

Apparently the borax solution + PVA/glue solution with which I am most familiar has some alternatives - sort of. There's the 'borax-free' variety using baking soda and contact solution, but the contact solution has to contain boric acid - which would be neutralized into...um...sodium borate (aka borax) with the addition of sodium bicarbonate (baking soda). There's also the option to just purchase pre-mixed activators, one of which - shown in the image - is Elmer's Magical Liquid.

With a quick check of the Magical Liquid's SDS, I see that it's a solution of boric acid, sodium bicarbonate, sodium chloride (?), and a couple of anti-microbial agents. The various concentrations seem lower than I would have thought: <1% boric acid, 1-5% sodium bicarbonate, <1% sodium chloride, and <0.5% of each of the preservatives. I'm feeling too lazy to do the math to do actual calculations, but I'm pretty sure the combined percentages - discounting the bicarbonate and the chloride masses - would come out decently below the 4% of the borax solution I'm used. Wonder if that's just a case of commerce allowing for the lower concentration leading to more needing to be purchased.

At $17 per quart (from Amazon as of 6/7/26 when I'm typing this up), the magical liquid has to be a high margin item for Elmer's. It's more expensive if you want your slime to be green-apple-scented. Sadly the cherry limeade scent looks to be sold out and might be out of production now - even though Elmer's still has it listed on their website.

Cherry limeade's my favorite...grape's favorite, too.

Strawberries make surprisingly GIANT bubbles (Best DIY Bubble Recipes)

I appreciate that Ben aka NightHawkInLight now shows his face in his videos. It's a little less creepy than having his videos narrated.

This video shows his findings to make the most durable, long-lasting giant bubbles out of Dawn dish soap, water, salt, baking soda, and J Lube. The titular comment about strawberries is because strawberry DNA is surprisingly easy to extract and highly prevalent within strawberry cells. 

Much of the video - from about 4:15-13:00 - is about Ben's attempts to extract the DNA from strawberries. It's a recreation of a fairly simple and common first year high school biology lab. 

From there, Ben tests his solutions with and without three different polymers - J Lube, strawberry DNA, PEO (polyethylene oxide, poly ox), and no polymer addition.

Then Ben re-tests solutions with an even larger bubble wand made of fishing poles. He does manage to make a few really gorgeous, colossal bubbles - some under lower humidity conditions and again when the humidity is approaching 100%. 

Along the way we do get a whole lot of Ben chuckles, so be prepared for that. 

If ever I want to make huge bubbles, the J Lube would be the recipe I'm looking to use. 

Making ULTRA-BRIGHT GLOWING GOO

Barnaby Dixon is an impressive puppeteer that I first heard about probably ten years ago. If you haven't checked out some of his work, do yourself a favor and spend a few minutes there first.

In this instructional video, Barnaby explains how he uses a thermoplastic polymer - a polymer that becomes flexible when it's heated above some temperature but is rigid below that same temperature. It's a great example of the polymer's glass transition phase change. Because polymers are mixtures, they don't necessarily have definite melting temperatures as pure substances like elements or compounds do. Instead they have ranges of temperatures during which they aren't quite solid or liquid but are flexible and moldable - think of hot glass being shapeable but not liquid.

I have some of this at school. It used to be available from Educational Innovations. That's where I bought it, but they sadly don't carry it anymore. Of course, just about anything is available at Amazon if you search for pcl moldeable plastic.

How One Company Secretly Poisoned the Planet

At some point in my material science and chemistry courses, I speak bluntly to my students that most research suggests that man-made polymers are bad for us.

Some are worse than others, but most research on the effects of polymers on humans seems to suggest that there are bad effects from most man-made polymers. Some are minorly bad, but others - like the family of PFAS - are more obviously and persistently bad.

The video above is short and has a direct message: DuPont is bad (or has acted badly).

The longer video below - from Veritasium - is far longer but is much, much more informative.

If this sounds familiar, you might've seen a semi-recent movie about this story, Dark Waters.

The worry about black food plastics...and a correction

This video was published by Adam Ragusea in November 2024 about a study from a month or so earlier than that. 

The tl;dr of the study is that many black plastics are produced from recycled black plastics that are frequently sourced from electronic waste which contains higher amounts of particularly toxic, flame-retardant chemicals. Those 'new' black plastic items could - especially if used in high heat areas like food flippers and turners on the stovetop - release higher than safe amounts of those chemicals.

In the above video, Adam goes through the possible concerns that this raises as well as noting a possible math error in the study's calculations suggesting that the level of concern is slightly lower than the authors might have initially suggested.

The article was corrected - noting exactly the math error that Adam suggested, and Adam published a spectacular video explaining why that error should not undermine faith in the scientific process or even in the researchers and authors of the original article.

The life and achievements of chemist Stephanie Kwolek, inventor of Kevlar

Stephanie Kwolek absolutely belongs in the inventors hall of fame, in the women's hall of fame, on the American Chemical Society's website, and on lots of other lists of honorees.

Stephanie Kwolek, you see, invented Kevlar at DuPont in 1965.

The Most Reflective Mirror In The World

Arrggghhh, Action Lab again.

I want to hunt down some of those dialectric mirrors. Their non-isotropic reflective materials sound pretty cool.

I am amazed that there is no metal in the material. It's just made of transparent polymer layers in alternating materials with different indices of refraction.

Food Plastics = Estrogens in Your Body

I promise that I'll have something fun and dopey for next week. We've been on a run of pretty heavy content mostly telling us that polymers are killing us.

I'm going to go outside and watch some butterflies.

PFAS roundup

Bunch of videos about PFAS because I can't bring myself to write the dozen of separate posts that these should all be posted as.

Watch one...take a break...come back and watch another. Don't run them all through at once. 

It's not cheery stuff, folks.

I am SO done with Teflon

My wife and I have been longtime purchasers and users of the Oxo Good Grips nonstick pans.

We would use the heck out of the 10" skillet and buy a new one when the surface got marred or started to stick - usually after a year and a half or two years. When we recently went looking, we found that it looks like Oxo is phasing out their nonstick skillet in favor of ceramic 'nonstick' skillets.

The reviews of the ceramic 'nonstick' skillets say that the ceramic layer is surprisingly close in performance to the teflon (or similar coating) that most nonstick skillets use but that the ceramic coating doesn't even last as long as the teflon coating meaning that we would have to buy replacement ceramic nonstick pans even more frequently than we're buying the teflon pans.

So we've gone looking for other nonstick replacements and have found that the list of possible replacements is fairly short: ceramic nonstick, cast iron, carbon steel, and stainless steel. Currently we're working on using our two fairly well seasons cast iron skillets more frequently. We'll see how that goes. 

More links to reviews of various alternatives to PFAS nonstick...

• Pots and Pans India
• Prudent Reviews
• Wired
• The Good Life designs
• Sprouting Fam
• The Kitchen Witches

"Forever Chemicals" Are Surprisingly Confusing

Man-made polymers are bad for us. 

Straight up, no qualifications to that statement from what I continue to read and learn.

PFAS and PFOS might just be the worst of them, and they are pretty well everywhere in the world around us, including inside most of us.

Better living through chemistry, eh?

油はちゃんと固まる？固めるテンプルを使った結果【講師：舐岡味郎】

I have absolutely no idea what's being said in the above video, but I like that it shows the time-lapse solidification of the cooking oil in the pan. That puts this video in the lead spot above this one which is in English but doesn't show the actual solidifying.

Now to the other admission that I have about today's topic. I can't find any thorough explanation of how the solidification process happens.

I've looked around and found a whole lot of people asking what the science is but with no acceptable answers. Fryaway - a similar product - has a blog post describing ways that oil can be solidified but never quite saying which method their product utilizes. 

They do say that their product is a "non-toxic, plant-based powder", and another blog shows an ingredient list for a similar product as being "natural oil", but that isn't much to go on.

If anybody can find more information specifically on the science of how these cooking oil hardeners work, I would be very much appreciative if you'd share.

I don't think it's one of these oil hardeners, but it might be.

Nonstick is prob safe - the factories aren't (PFAS contamination)

During my senior year at Wabash College I wrote a column for our student newspaper, The Bachelor. In one of the columns, I put forth my thoughts about the damage we were doing to the environment. I can sum my thoughts up then as 'in the short run, we're clearly destroying our environment...in the long enough run, the planet won't even remember we were here.' 

Amazingly, my thoughts on that haven't much changed in the two and a half decades since I wrote that column, though my thoughts as to how we're poisoning our environment have been informed by a bit more learning about science since then. I'm pretty sure it's the polymers that will be our undoing. We're making remarkably stable molecules that are inherently hostile to all living things at the moment - at least until something evolves to consume them, which will hopefully happen eventually - and we're doing so in remarkable volume.

If there's one thing we need to do to save the life on our planet, it's to stop mucking about with polymers. Stop making them. Stop burning them. Stop refining them.

Don't Play With ACID SLIME

Why would you ever think that making acid slime was a smart thing?

Making a video and project based on a moronic YouTube comment seems like a really bad idea, not necessarily anything especially dangerous, just something dumb.

The acid clearly doesn't let the slime 'set up' which isn't really all that surprising because polyvinyl alcohol slime holds together via cross linking (check the graphics here), and the extra hydrogen ions would likely break down all of those cross links - if not even depolymerize the PVA.

The pH test strips, by the way, are absolutely useless there because all of the acids that they're testing would have pHs well below 1, leaving them likely outside the useful range of the strips.

That was dumb.

GIANT Liquid Nitrogen Rockets: Explodes In My Face

The title's a bit of an oversell.

Yeah, I know, you're shocked that a youtube video would use a clickbait title.

The bottle does, however, explode just above the host's head. That happens for a couple of reasons, primarily that the bottle he used for that part of the experiment is made for holding change not for holding pressurized gases and liquids. The polymer involved is more rigid, weaker, and assembled in two parts rather than as a single shell.

All that being said, I'm really happy with the safety precautions that the host takes. He's wearing gloves to protect against the cold and a face shield to protect his face and eyes. I do wish he had some earplugs in because the explosion can be loud, but he did at least take decent precautions.

Don't do this, folks...but do watch this.

Gaviscon Worms - Cool Science Experiment

I've never tried the gummi worm procedure that Steve shows off at the beginning, but I really want to. Wonder if sodium alginate is available in a glowy solution like he uses...probably from his website.

The formation of the 'worms' is curious. In looking Gaviscon up at Wikipedia, here's what I found...

The formulation of Gaviscon varies by manufacturer. The three active ingredients in Reckitt Benckiser's version are sodium alginate, a bicarbonate (either sodium or potassium in variants) and an antacid (calcium carbonate). The GlaxoSmithKline variant lists only antacids as its active ingredients (aluminum hydroxide and either magnesium carbonate or magnesium trisilicate). Alginic acid and sodium bicarbonate are listed as inactive ingredients. The combination of alginic acid and a bicarbonate forms a layer on the contents of the stomach, which prevents stomach acid from refluxing up into the esophagus. If reflux does occur the protective barrier is the first to contact the esophageal mucosa, instead of gastric contents.

What will science think of next?