Make: Online: Chemistry Archives

Archive: Chemistry

July 2, 2009

Metallurgical eye candy

An alloy of 1.3% copper, 0.3% magnesium, and 0.3% manganese in aluminum, etched with potassium permanganate and lye.

So I woke up this morning all pumped up to blog about metallography. If you don't already know, metallography is a type of scientific microimaging that involves mirror-polishing metal surfaces and then etching them with various reagents to reveal their microstructures, which are often of breathtaking beauty.

"Griffith Cannon Flash," by Dr. Frederick E. Schmidt, from the iron of a cannon used at Gettysburg.

Unfortunately, there aren't a lot of these images online. ASM International, the big metallurgical professional society, has a large online database of metallographs, but it's locked away behind a members-only paywall. Except for a couple of skimpy .PDFs (2007, 2008), even the winners of their annual International Metallographic Contest seem to go largely unpublicized.

Which is a shame, not only because the images themselves are so beautiful, but because they could inspire a whole culture of amateur and artistic metallographers that does not, as far as I can tell, presently exist. Which fact also surprises me, by the way, because the equipment and techniques of metallography are very accessible to amateurs, especially relative to other modern methods of materials analysis.

"Grain structure in CC cast 3304 aluminum alloy," by Elana Naez.

If you know of anyone who's making metallographs as a hobby or as a means of personal artistic expression, please drop me a link in the comments.

How-To: Homemade sunscreen

Scoochmaroo shares this recipe for basic sunscreen free of the umpteen additives used in commercial varieties.

Sunscreen is intended to shield your skin from harmful UVA and UVB rays. These can cause premature aging, and more tragically, skin cancer. But commercial suncreens often involve more nasty chemicals than necessary.

By making your own sunscreen, you control exactly what goes in!

In addition to some natural oils and emulsifying wax, the ingredients list calls for either zinc oxide or titanium dioxide as a sun-blocking agent (both can be found from online suppliers). Read on for the how-to over @ Instructables

June 30, 2009

How-To: Make pyrophoric iron

A former chemistry teacher of mine provided a great definition of "pyrophoric:"

[It] means that if you playfully squirt some at your lab mates, they will burst into flame.

In other (less amusing) words, a "pyrophoric" substance is one that ignites spontaneously on exposure to air.
Pyrophoric iron, however, isn't as dangerous as that makes it sound, especially in small quantities.

Basically, the oxidation of iron is so vigorous that it can cause very finely divided iron metal to become incandescent. Amazing Rust has a great tutorial on how to prepare finely divided iron by thermolyzing iron oxalate, a yellow powder that can, in turn, be prepared by a simple reaction between two common chemicals.

June 25, 2009

Thinking of building a solar still?

Build It Solar has a great collection of solar DIY projects, including stills, cookers, food driers, and water heaters. But the gem of their solar-distillation collection, for my money, is this paper, from 1985, by Horace McCracken and Joel Gordes. It's unformatted ASCII and black-and-white GIFs, but it provides a better review of the various designs of solar stills, and the theory that informs their design and operation, than anything else I've found in the tubes.

From the pages of MAKE:

If you're interested in all things solar, be sure to check out Parker Jardine's Solar Power System Design in MAKE 14.

More:

June 23, 2009

Library of strange compounds

George Pendle wrote the highly-recommended Strange Angel: The Otherworldly Life of Rocket Scientist John Whiteside Parsons, the biography of rocket pioneer Jack Parsons (whom I profiled in MAKE, Volume 13). In Saturday's Financial Times, George writes about the Materials Library at King's College, London.

Deep in the bowels of a brutalist concrete building on the Strand, long shelves are packed - crammed, really - with some of the world's strangest substances, from the past, present and sometimes, it seems, the future. Take Aerogel: the world's lightest solid consists of 99.8 per cent air and looks like a vague, hazy mass. And yet despite its insubstantial nature, it is remarkably strong; and because of its ability to nullify convection, conduction and radiation, it also happens to be the best insulator in the world. Sitting next to the Aerogel is its thermal opposite, a piece of aluminium nitride, which is such an effective conductor of heat that if you grasp a blunt wafer of it in your hand, the warmth of your body alone allows it to cut through ice. Nearby are panes of glass that clean themselves, metal that remembers the last shape it was twisted into, and a thin tube of Tin Stick which, when bent, emits a sound like a human cry. There's a tub of totally inert fluorocarbon liquid into which any electronic device can be placed and continue to function. The same liquid has been used to replace the blood in lab rats, which also, oddly enough, continue to function.

A library of the world's most unusual compounds [via Boing Boing]

June 20, 2009

Secret ink smorgasboard

Here is a nice round-up of some simple sneaky inks. The old favorites like lemon juice and vinegar are there, but also some more sophisticated systems using stuff like cerium oxalate and iodine fuming.

From the pages of MAKE:

Mike Golembewksi shows us how to make an invisible inkjet printer in MAKE 16 - Spy Tech.

More:

June 17, 2009

Book Review: Caveman Chemistry by Kevin Dunn

My recent post on glassknapping mentioned Kevin Dunn's 2003 book Caveman Chemistry, and I've received many requests for a dedicated review. So here goes!

Caveman Chemistry came to my attention a few years ago through the Lindsay Technical Books catalog. I'm a chemist by profession and a hacker by calling, with a long-standing interest in garage science, so the book's title was basically irresistible to me. I plunked down my nickel and twiddled my thumbs for a week while the snails carried it to my doorstep.

Read full story

June 11, 2009

Endless sustainable power at the sea floor

"Benthic microbial fuel cell" is propeller-head code for the following very interesting fact: If you bury a metal plate a few centimeters beneath the ocean floor, and elevate a parallel plate a few centimeters above the ocean floor, the potential between them (due to ongoing microbial metabolism in the sediment) is enough to generate useful power. 800mV is a typical figure, but if I understand correctly, the current is directly related to the area of the plates, so the amount of power available by this method is theoretically only limited by the size of the plates you can install. Mark Nielsen is a doctoral candidate at Oregon State University under Dr. Clare Reimers, an expert in the field. This page at the OSU website provides a nice general overview of the concept and of Mark's work in particular.

June 5, 2009

Make: Projects - Thermochromic Maker's Notebook

Here's an easy hack for your Maker's Notebook that's sure to get noticed: Buy some thermochromic liquid crystal (LC) film and attach it to the cover! Originally I bought LC film from US suppliers and tried gluing it on. I tested three different adhesives (3M Super77, DAP Weldwood Contact Cement, and Elmer's Craft Glue) and ruined one notebook and several pieces of film before discovering this self-adhesive LC film available from MUTR in the United Kingdom. (The 30x45cm size is necessary.) It works great! I cut two rectangles [5 3/8" (13.65 cm) x 6 7/8" (17.46 cm)] using a swing arm paper cutter, peeled off the protective backing, and carefully smoothed the film in place on both front and back covers, first with my fingers, and then using a rolling pin. See the video for some cool thermochromic effects.

Subscribe to the MAKE podcast in iTunes, or download the m4v file.

June 3, 2009

Theo Gray on why "safety" is overrated

The most awesome Theo Gray, author of the I-can't-recommend-it-highly-enough Mad Science, has a post on Powell's Books blog about his book and the dangers it contains (the subtitle is "Experiments You Can Do at Home -- But Probably Shouldn't"). He writes:

Is it irresponsible to write a mass-market book that describes how to do dangerous science experiments? It used to be very common. I have books from the early 1800s through the mid 1900s that would make your hair stand on end. One 1930s book from none other than the Popular Science Press includes the recipe for Armstrong's mixture, a friction-sensitive explosive notorious for blowing hands off while it's being mixed.
But that's ancient history now. Books of home science, and even classroom chemistry at the high school level, are filled with baking soda and vinegar science. The Dangerous Book for Boys, for example, is completely devoid of danger.

Surely recommending only perfectly safe experiments is a good thing, isn't it?

Is Science As Important As Football?

May 22, 2009

Environmental test kits of my youth

I was out to dinner the other night with O'Reilly/MAKE's Brian Jepson, his wife Joan, and our new Make: Online author Kipp Bradford. We were talking about the awesome Thames & Kosmos science and tech kits we carry in the Maker Shed. The conversation inevitably turned to chemistry kits of yore, the beloved kits of our childhoods. Usually, I immediately go to my Gilbert sets, but this time, I flashed on a kit I'd largely forgotten about: The Johnny Horizon Environmental Test Kit. I think I was 14 when I got it.

I grew up in Chester, VA, the small town over from Hopewell, the "Chemical Capital of the South." On days when the wind blew out of the south, it was as if the Devil himself had farted on our sleepy little town. Armed with my Johnny Horizon Test Kit, I was determined to prove that Hopewell was hurting us. I did all of the tests in the kit -- suspended particles, wind-blown particles, Coliform, pH, smoke density, nylon deterioration, etc. I did them as a science project and showed that the industrial zone between Hopewell and Chester was crankin' crud into the air and water that was beyond allowable levels (in some tests). Nothing really ever came of it (except an A+ on the project), but it felt really empowering to get this kit, trudge off into the woods, and collect scientific data that actually painted a picture of what was happening in the surrounding area because of these plants. I still remember the canal that I went to next to one plant and how creepy it was -- everything was dead, choked with trash and the sulfurous reek of chemicals. It was like something out of a Troma sci-fi/horror film. Whenever I see that three-eyed fish on The Simpsons, I always think of Hopewell, Va, circa the mid-70s.

At the dinner, Brian asked if I'd ever thought to look up the Test Kit on the web. I'd looked up other kits, but not this one. As soon as I got home, I did, and found this page. Pleasant memories came flooding back (along with some unpleasant ones involving hellish flatulence).

(BTW: Hopewell, VA was thrust onto the national stage a few years later with the "Kepone disaster" of 1975, when workers at a plant that produced the pesticide Kepone got sick from over-exposure. Dozens of workers were affected, it costs many millions in clean-up, and fishing in the James River was shut down for years in the aftermath. One article I found online quoted the cardiologist who first linked the symptoms to the pesticide saying that this incident "really opened up awareness of how chemicals can affect the environment." I *tried* to tell them :-) Me and Johnny Horizon.)

May 21, 2009

Molecular gastronomy at Maker Faire Bay Area

In MAKE Volume 14, Michael Zbyszynski showed us how to really geek out in the kitchen by introducing us to molecular gastronomy, a movement happening in the culinary world. As he describes it, "Essentially, it involves applying scientific techniques and methodologies to the cooking process. One of the more interesting techniques is the use of common substances to control the texture of foods, often in surprising ways. You don't need a chemistry lab to pull off such effects. With a few inexpensive tools and chemicals, it's possible to use spherification to make all kinds of 'caviar' (and other shapes) in your own kitchen." Michael showed us how to make a "spherical array" (that's Michael pictured above in his kitchen with the array he made) that enables you to quickly make many pieces of caviar. He also shared a recipe to make juice caviar and incorporate it into molecular mojitos! The method isolates the cocktail's ingredients into individual caviars, each with its own distinct color and flavor. The drink flavors come together on the tongue. Here's a closeup of the spherical array:

And here's the molecular mojito:

Michael is joining us again this year at Maker Faire Bay Area on May30th and 31st in San Mateo, Calif. Come on out and meet him, and watch his live molecular gastronomy demonstrations!

May 19, 2009

Thin layer chromatography in the kitchen

During my six-odd years as a graduate organic chemist, probably the cheapest, most powerful, and most commonly used analytical laboratory technique in my bag of tricks was thin-layer chromatography. Explaining chromatography theory is a big job, but the idea boils down pretty well to this: chromatography is the art of taking a complex mixture with all sorts of compounds in it and separating them out one at a time.

There are a couple of reasons you might want to do this: First, because you only want one of those compounds and need to purify it by getting rid of the rest. This is called "preparative" chromatography and it is a complex and relatively expensive endeavor. But the other common reason for performing separations is analytical: You want to get an idea of how many compounds are in there and whether or not one of them is compound "X." Thin-layer chromatography lets you do this, on a bench-top, with a few cents worth of materials and a few minutes of time. It's unbelievably powerful for such an inexpensive technique, and Science Project Lab has a great tutorial on getting started at home.

May 18, 2009

Stone age superglue!

From National Geographic:

Ancient people in what is now South Africa whipped up a glue of powdered red ochre and acacia-tree gum to keep their tools (above, a replicated tool with adhesive made by scientists) intact, a May 2009 study says.

Stone Age Superglue Found -- Hints at Unknown Smarts?

May 13, 2009

How-To: Detecting mercury in light bulbs

I thought this chemistry video by Jen K was really interesting. You may not be able to perform this particular experiment at home since you need access to an Atomic Absorption Spectrometer. However, the video does give an interesting look at how they perform this experiment in the lab.

Mercury is detected in light bulbs by adding various oxidizing reagents to break down organic complexes into mercuric ion. The AAS instrument is then used to give a mercury concentration value.

How to: Detecting mercury in light bulbs

In the Maker Shed:

In the Maker Shed: Chemistry Experiment Kit 3000

May 5, 2009

Bill Gurstelle on Dippy Bird science

As a little kid, maybe five or six, one of my first remembered moments of heightened mechanical curiosity was over a Dippy Bird that somebody gave us. I have this very vivid memory of being utterly fascinated by it and wondering how it worked. The answer has been decades in coming. Here, MAKE Contributing Editor Bill Gurstelle, talks about Methylene Chloride, a plastic weld, and its use in powering Dippy Birds.

Methylene Chloride is the bonding agent I used to attach one piece of polycarbonate plastic to another piece when I was constructing the firepiston (see Feb 13 post in this blog.) MC works well because it's thin and penetrates into seams well and does a good job of dissolving the plastic so it solvent welds together.
Coincidentally, I found out, while researching that methylene chloride is the same stuff used in the Dippy Birds to make them go up and down. The science of Dippy Birds, according to the How Stuff Works website, are this:

1. When water evaporates from the fuzz on the Dippy Bird's head, the head is cooled.
2. The temperature decrease in the head condenses the methylene chloride vapor, decreasing the vapor pressure in the head relative to the vapor pressure in the abdomen.
3. The greater vapor pressure in the abdomen forces fluid up through the neck and into the head.
4. As fluid enters the head, it makes the Dippy Bird top-heavy.
5. The bird tips. Liquid travels to the head. The bottom of the tube is no longer submerged in liquid.
6. Vapor bubbles travel through the tube and into the head. Liquid drains from the head, displaced by the bubbles.
7. Fluid drains back into the abdomen, making the bird bottom-heavy.
8. The bird tips back up.

Methylene chloride is also used, apparently, in decaffeinating coffee. The MSDS says the stuff is somewhat dangerous, but apparently, not so much that it cannot be used in Dippy Bird toys - at least until someone complains.

Methylene Chloride and Dippy Bird Science

April 18, 2009

NOVA teaches teachers

Image from NOVA on PBS

Looking for some great resources for your classroom? You may want to check out some of the fantastic tools provided by NOVA on PBS. You can check out their offerings by subject also.

They have a weekly feature, which right now is showing Car of the Future.

Activity Summary Student teams research and develop a proposal to decrease the carbon footprint of their city's public transportation system through the use of various new technologies and/or alternative fuels. Students prepare a report that explains why their transportation plan is the best one for their community.
Learning Objectives
Students will be able to:

understand the pros and cons of adopting new technologies or alternative fuels to replace existing gasoline-powered vehicles.
describe the environmental impact of alternative fuels.

Suggested Time
Four class periods

It looks like there is quite a bit of depth to these classroom resources. Links, videos, background information, and more should help you to undertake some interesting and complex studies of contemporary science and technology.

These projects are mapped to the National Science Education Standards, but I still can't find a good online resource for state by state curriculum frameworks. The Massachusetts frameworks are something of a hodgepodge of formats, and it is difficult to link directly to each individual item. Generally, they are huge documents of dozens or hundreds of pages in pdf or doc format covering many subjects and grades K-12. With no web-friendly indexing ability, it is kind of difficult to map a project directly to the subject and level.

Have you used the NOVA teachers' resources? Where do you turn for curriculum materials? Do you keep online resources for your classroom? Let us know in the comments.

April 15, 2009

Behold: the flaming bacon lance of death!

Over at Boing Boing TV, Xeni has posted an awesome video of Theo Gray using prosciutto ham to cut through steel. For the vegans in the audience, he also works wonders with a cuke and some breadsticks.

BB Video: The Flaming Bacon Lance of Death, from Theo Gray's book "Mad Science"

More:
Make: Talk #005 show notes and next episode (where we talk about Theo's book)

April 13, 2009

Backyard metal casting

MAKE subscriber Pete Marchetto pointed us to this awesome site covering all manner of backyard metal casting. In fact, that's its name: Backyard Metal Casting. Peter writes:

Blame Kaden Harris. He got me onto this wonderful site describing many metal casting and metalworking projects.

Okay, Kaden. It's all your fault we're posting this link. You should be.... ashamed?

Backyard Metal Casting

March 7, 2009

Home Chemistry excerpt: Keeping a Lab Notebook

People sometimes ask us what's the big deal with the Maker's Notebook. Why should they care about a book largely filled with blank pages? Well, obviously we think there are all sorts of reasons to care. We spent a lot of time designing a book optimized for makers. It's hard-bound, sturdy, contains high-quality engineering graph paper, has 20 pages of useful (and/or entertaining) reference material in the back, it's beautiful (we think), etc. But one of the main things we were conscious of, and got lots of input on, was making the book laboratory-compliant. You may not be aware of it but science and engineering labs technicians, inventors, and others doing research, experimentation, and design that might become novel discoveries or products, have to keep notebooks that meet certain legal standards. For example, they must have pre-numbered, non-removable pages. They must have a place to date, sign, and have witnessed each page of work. So we made our notebook to conform to these standards.

In this Flashback column, we excerpt the "Maintaining a Laboratory Notebook" section of Bob Thompson's Illustrated Guide to Home Chemistry Experiments. This section details everything you need to know to keep a laboratory notebook (and a Maker's Notebook) to a professional standard.

9780596514921-2T

Maintaining a Laboratory Notebook
A laboratory notebook is a contemporaneous, permanent primary record of the owner's laboratory work. In real-world corporate and industrial chemistry labs, the lab notebook is often a critically important document, for both scientific and legal reasons. The outcome of zillion-dollar patent lawsuits often hinges on the quality, completeness, and credibility of a lab notebook. Many corporations have detailed procedures that must be followed in maintaining and archiving lab notebooks, and some go so far as to have the individual pages of researchers' lab notebooks notarized and imaged on a daily or weekly basis.

If you're just starting to learn about chemistry lab work, keeping a detailed lab notebook may seem to be overkill, but it's not. Although this book provides tables for recording data and spaces for answering the questions it poses, that's really for the convenience of hobbyist readers. If you're using this book to prepare for college chemistry, and particularly if you plan to take the Advanced Placement (AP) Chemistry exam, you should keep a lab notebook. Even if you score a 5 on the AP Chemistry exam, many college and university chemistry departments will not offer you advanced placement unless you can show them a lab notebook that meets their standards.

Laboratory Notebook Guidelines
Use the following guidelines to maintain your laboratory notebook:

The notebook must be permanently bound. Looseleaf pages are unacceptable. Never tear a page out of the notebook.

Use permanent ink. Pencil or erasable ink is unacceptable. Erasures are anathema.

Before you use it, print your name and other contact information on the front of the notebook, as well as the volume number (if applicable) and the date you started using the notebook.

Number every page, odd and even, at the top outer corner, before you begin using the notebook.

Reserve the first few pages for a table of contents.

Begin a new page for each experiment.

Use only the righthand pages for recording information. The lefthand pages can be used for scratch paper. (If you are lefthanded, you may use the lefthand pages for recording information, but maintain consistency throughout.)

Record all observations as you make them. Do not trust your memory, even for a minute.

Print all information legibly, preferably in block letters. Do not write longhand.

If you make a mistake, draw one line through the erroneous information, leaving it readable. If it is not otherwise obvious, include a short note explaining the reason for the strikethrough. Date and initial the strikethrough.

Do not leave gaps or whitespace in the notebook. Cross out whitespace if leaving an open place in the notebook is unavoidable. That way, no one can go back in and fill in something that didn't happen. When you complete an experiment, cross out the whitespace that remains at the bottom of the final page.

Incorporate computer-generated graphs, charts, printouts, photographs, and similar items by taping or pasting them into the notebook. Date and initial all add-ins.

Include only procedures that you personally perform and data that you personally observe. If you are working with a lab partner and taking shared responsibility for performing procedures and observing data, note that fact as well as describing who did what and when.

Remember that the ultimate goal of a laboratory notebook is to provide a permanent record of all the information necessary for someone else to reproduce your experiment and replicate your results. Leave nothing out. Even the smallest, apparently trivial, detail may make the difference.