DIY Strontium Aluminate Glows In The Dark

January 20, 2025 by Al Williams 8 Comments

[Maurycyz] points out right up front: several of the reagents used are very corrosive and can produce toxic gasses. We weren’t sure if they were trying to dissuade us not to replicate it or encourage us to do so. The project in question is making strontium aluminate which, by the way, glows in the dark.

The material grows strongly for hours and, despite the dangers of making it, it doesn’t require anything very exotic. As [Maurycyz] points out, oxygen and aluminum are everywhere. Strontium sounds uncommon, but apparently, it is used in ceramics.

For the chemists among us, there’s an explanation of how to make it by decomposing soluble nitrate salts. For the rest of us, the steps are to make aluminum hydroxide using potassium alum, a food preservative, and sodium hydroxide. Then, it is mixed with nitric acid, strontium carbonate, europium, and dysprosium. Those last elements determine the color of the glow.

A drying step removes the acid, followed by dissolving with urea and water. The heat of the reaction wasn’t enough to form the final product, but it took time with an oxy-propane torch to form blobs of strontium aluminate. The product may not have been pure, because it didn’t glow for hours like commercial preparations. But it did manage to glow for a few minutes after light exposure.

We try to limit our chemistry to less toxic substances, although ferric chloride can make a mess. You could probably track down the impurities with a gas chromatograph. What we really want is a glow-in-the-dark car antenna.

Simple Fluorometer Makes Nucleic Acid Detection Cheap And Easy

December 18, 2024 by Dan Maloney 9 Comments

Back in the bad old days, dealing with DNA and RNA in a lab setting was often fraught with peril. Detection technologies were limited to radioisotopes and hideous chemicals like ethidium bromide, a cherry-red solution that was a fast track to cancer if accidentally ingested. It took time, patience, and plenty of training to use them, and even then, mistakes were commonplace.

Luckily, things have progressed a lot since then, and fluorescence detection of nucleic acids has become much more common. The trouble is that the instruments needed to quantify these signals are priced out of the range of those who could benefit most from them. That’s why [Will Anderson] et al. came up with DIYNAFLUOR, an open-source nucleic acid fluorometer that can be built on a budget. The chemical principles behind fluorometry are simple — certain fluorescent dyes have the property of emitting much more light when they are bound to DNA or RNA than when they’re unbound, and that light can be measured easily. DIYNAFLUOR uses 3D-printed parts to hold a sample tube in an optical chamber that has a UV LED for excitation of the sample and a TLS2591 digital light sensor to read the emitted light. Optical bandpass filters clean up the excitation and emission spectra, and an Arduino runs the show.

The DIYNAFLUOR team put a lot of effort into making sure their instrument can get into as many hands as possible. First is the low BOM cost of around $40, which alone will open a lot of opportunities. They’ve also concentrated on making assembly as easy as possible, with a solder-optional design and printed parts that assemble with simple fasteners. The obvious target demographic for DIYNAFLUOR is STEM students, but the group also wants to see this used in austere settings such as field research and environmental monitoring. There’s a preprint available that shows results with commercial fluorescence nucleic acid detection kits, as well as detailing homebrew reagents that can be made in even modestly equipped labs.

Ore To Iron In A Few Seconds: New Chinese Process Will Revolutionise Smelting

December 12, 2024 by Jenny List 93 Comments

The process of ironmaking has relied for centuries on iron ore, an impure form of iron oxide, slowly being reduced to iron by carbon monoxide in a furnace. Whether that furnace is the charcoal fire of an Iron Age craftsman or a modern blast furnace, the fundamental process remains the same, even if the technology around it has been refined. Now details are emerging of a new take on iron smelting from China, which turns what has always been a slow and intensive process into one that only takes a few seconds. So-called flash ironmaking relies on the injection of a fine iron ore powder into a superheated furnace, with the reduction happening explosively and delivering a constant stream of molten iron.

Frustratingly there is little detail on how it works, with the primary source for the news coverage being a paywalled South China Morning Post article. The journal article alluded to has proved frustratingly difficult to find online, leaving us with a few questions as to how it all works. Is the reducing agent still carbon monoxide, for example, or do they use another one such as hydrogen? The interesting part from an economic perspective is that it’s said to work on lower-grade ores, opening up the prospect for the Chinese steelmakers relying less on imports. There’s no work though on how the process would deal with the inevitable slag such ore would create.

If any readers have journal access we’d be interested in some insight in the comments, and we’re sure this story will deliver fresh information over time. Having been part of building a blast furnace of our own in the past, it’s something we find interesting

Fully Submerge This Modernized PH Sensor

November 29, 2024 by Bryan Cockfield 18 Comments

There’s a school of thought that says you shouldn’t mess around with a solution that’s already working, but that’s never seemed to stop anyone in this community. When [Skye] was looking at the current state of connected pH meters they realized there was incredible room for improvement.

Called the Nectar Monitor, this pH meter is a more modern take on what is currently offered in this space. Open source and based on the ESP32, it’s accessible to most people with a soldering iron, fits into a standard project box, and includes other modern features like USB and WiFi connectivity. It can even measure conductivity and temperature. But the main improvement here is that unlike other monitors that can only be submerged temporarily, this one is designed to be under water for long time periods thanks to a specially designed probe and electrical isolation.

This design makes it an appealing choice for people with aquariums, hydroponic farms, or any other situation where constant monitoring of pH is extremely important to maintaining a balanced system. We’ve seen some unique takes on hydroponics before especially, including this build that moves the plants instead of the nutrient solution and this fully automated indoor garden.

Boss Byproducts: Corium Is Man-Made Lava

November 27, 2024 by Kristina Panos 19 Comments

So now we’ve talked about all kinds of byproducts, including man-made (Fordite), nature-made (fulgurites), and one that’s a little of both (calthemites). Each of these is beautiful in its own way, but I’m not sure about the beauty and merit of corium — that which is created in a nuclear reactor core during a meltdown.

A necklace made to look like corium. Image via OSS-OSS

Corium has the consistency of lava and is made up of many things, including nuclear fuel, the products of fission, control rods, any structural parts of the reactor that were affected, and products of those parts’ reaction with the surrounding air, water, and steam.

If the reactor vessel itself is breached, corium can include molten concrete from the floor underneath. That said, if corium is hot enough, it can melt any concrete it comes in contact with.

So, I had to ask, is there corium jewelry? Not quite. Corium is dangerous and hard to come by. But that doesn’t stop artisans from imitating the substance with other materials.

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Boss Byproducts: Calthemites Are Man-Made Cave Dwellers

November 20, 2024 by Kristina Panos 6 Comments

Some lovely orange calthemite flowstone colored so by iron oxide from rusting steel reinforcing. Image via Wikipedia

At this point, we’ve learned about man-made byproducts and nature-made byproducts. But how about one that’s a little of both? I’m talking about calthemites, which are secondary deposits that form in those man-made caves such as parking garages, mines, and tunnels.

Calthemites grow both on and under these structures in forms that mimic natural cave speleothems like stalactites, stalagmites, flowstone, and so on. They are often the result of an hyperalkalinic solution of pH 9-14 seeping through a concrete structure to the point of coming into contact with the air on the underside. Here, carbon dioxide in the air facilitates the necessary reactions to secondarily deposit calcium carbonate.

These calcium carbonate deposits are usually white, but can be colored red, orange, or yellow thanks to iron oxide. If copper pipes are around, copper oxide can cause calthemites to be blue or green. As pretty as all that sounds, I didn’t find any evidence of these parking garage growths having been turned into jewelry. So there’s your million-dollar idea.

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Homebrew PH Meter Uses Antimony Electrode

November 15, 2024 by Dan Maloney 11 Comments

Understanding the nature of pH has bedeviled beginning (and not-so-beginning) chemistry students for nearly as long as chemistry has had students. It all seems so arbitrary, being the base-10 log of the inverse of hydrogen ion concentration and with a measurement range of 0 to 14. Add to that the electrochemical reactions needed to measure pH electronically, and it’s enough to make your head spin.

Difficulties aside, [Markus Bindhammer] decided to tackle the topic and came up with this interesting digital pH meter as a result. Measuring pH electronically is all about the electrode, or rather a pair of electrodes, one of which is a reference electrode. The potential difference between the electrodes when dipped into the solution under test correlates to the pH of the solution. [Markus] created his electrode by drawing molten antimony into a length of borosilicate glass tubing containing a solid copper wire as a terminal. The reference electrode was made from another piece of glass tubing, also with a copper terminal but filled with a saturated solution of copper(II) sulfate and plugged with a wooden skewer soaked in potassium nitrate.

In theory, this electrode system should result in a linear correlation between the pH of the test solution and the potential difference between the electrodes, easily measured with a multimeter. [Marb]’s results were a little different, though, leading him to use a microcontroller to scale the electrode output and display the pH on an OLED.

The relaxing video below shows the build process and more detail on the electrochemistry involved. It might be worth getting your head around this, since liquid metal batteries based on antimony are becoming a thing.

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