Perfluorooctanesulfonates – Beneficial, Yet Pervasive, Problematic

Health, Technology
Perflurooctanesulfonates or PFOs are simple compounds, not found in nature. They are derivatives of perfluorooctanesulfonic acid. Their chemical structure includes atoms of carbon, fluorine, sulfur, and oxygen. Various ways of writing the acid's formula are seen in the illustration, top to bottom – the simplest to the most complex, followed by a ball-and-stick model. Commercial Sales Search for the acid online, and you will find it. It can be purchased as the free acid. However, it is also sold in compound form, such as the tetramethylammonium or tetraethylammonium salts. Useful? There's no question these substances are useful. Consider this... The structure of this acid is not unlike the chemical structure of Teflon®. Teflon is slippery stuff. Teflon, however, is a solid. What if a similar, only soluble, substance could be…
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Carbide Cannons & Miners’ Lamps – The Chemistry?

Chemistry, Technology
When I was a kid, a friend showed me what he called an acetylene cannon. Many know it as a carbide cannon. What made it work? It's all a matter of chemistry. Which Carbide? A carbide is a compound in which carbon is bonded to a more electropositive element. Silicon carbide (SiC) and tungsten carbide (WC) are two well-known examples. What carbide do carbide cannons use? Calcium Carbide The answer is calcium carbide. Lime and coke are placed in an electric furnace. The chemical reaction is: CaO + 3 C → CaC2 + CO2↑ What makes calcium oxide so interesting is its bonding. The valence of calcium is +2. Ordinarily, carbon is assigned a valence of 4. Something's strange here... The puzzle is solved if we write the structure of…
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Anodizing Aluminum: How Can It Be Done?

Astronomy, Chemistry, Technology
Aluminum is a versatile metal, yet in order to be used in certain applications, it needs to be modified, improved. One way of modifying it is to add certain ingredients, such as a trace of copper, to toughen it. Another modification is the process of anodizing aluminum. What does that refer to? Anode & Cathode We're all familiar with electroplating. We may have eaten meals using silver-plate utensils. Or we may have attended a classic auto show in which older cars have chrome-plated bumpers. A metal coating (plating) from a chemical bath is applied using electricity to transfer the metal from a supply source (the anode) to the object to be plated (the cathode). The simplified artwork below illustrates a copper bath, complete with anode, cathode, and plating solution. A…
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Tires to Lemons – Well, Not Exactly

Chemistry, Technology
Although individuals and governments fall far short of maintaining Earth's pristine qualities, many do desire to minimize waste and its first cousin, pollution. Although one admirable action would be to minimize production, another is to recycle the resultant wastes. The late 19th and early 20th centuries introduced industrialization, and with it mechanization. Part of the mechanization was the automobile. And part of the automobile was the automobile tire. Tires are constructed of rubber or rubber-related products. They wear out well before most automobiles wear out. The problem is: what to do with all those worn-out, used tires? Millions and millions of them. They do not readily break down on being exposed to the elements. How can they be recycled? One Problem with Tires Now What might happen if tires were…
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Algae – When Life Hands You a Lemon

Plants, Technology
You purchase a fish tank, obtain the gravel, fixtures, pump, and filter. You set it up, making sure the tank chemistry is correct. Finally, you purchase a modest number of compatible fish, adjusting tank temperature to fit their needs, adjust the light for their comfort. It's beautiful! But after a while you notice... what's this? A kind of green slime, algae! Oh, bother. Why does that stuff have to come along and ruin things? So you purchase algae eaters and wage the same war that other enthusiasts fight. It seems that life keeps giving you lemons. So make lemonade! The Good, the Bad, and the Algae A little algae here or there is a part of nature and not ordinarily a problem. But sometimes it just plain takes over. Notice…
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Motor Oil Degradation in Automotive Engines

Chemistry, Technology
Why is it so important to change the motor oil in your car? The answer is due to motor oil degradation. Unrecycled motor oils originate from naturally occurring crude oil. As such, motor oils are necessarily a complex combination of organic compounds: Molecules made simply of carbon and hydrogen. A percentage of these hydrocarbons include ring structures—whether saturated aliphatic rings or aromatic rings (benzene or polycyclic). However, the largest percentage of motor engine oil consists of straight and branched chain hydrocarbons of varying lengths. Motor oils are high-quality lubricants, but even the best of these products will degrade with use. Why is Oil a Lubricant? A good lubricant must readily flow and have sufficient viscosity. It should not freeze in even cold environments. It should possess a high level of…
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What is Peat Moss? How Could It Harm the Environment?

Plants, Technology
[caption id="attachment_24609" align="alignright" width="480"] A beautiful peat moss bog.[/caption] Peat is composed largely of sphagnum and other mosses, although some other plant material may be included. Because these plants grow in wetlands, the abundance of water decaying plants breakdown slowly and without the presence of oxygen. That is, decomposition is anaerobic, more than aerobic. Commercializing Peat Moss Harvested peat is employed in a number of ways. Perhaps best known is its use as a soil amendment and in the manufacture of peat pots for seed germination. In some regions, dried peat is used for the generation of electric power. There might not be much impact from this, except over large periods of time, meters-deep peat bogs form. They become a valuable resource. However, the need for peat is sometimes less…
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Cooling Atoms to Millionths of 1 Degree by Laser?

Physics, Technology
[caption id="attachment_24362" align="alignright" width="480"] Laser trapped erbium atoms. Image by NIST[/caption] Laser cooling refers to a variety of techniques. The most common method is Doppler laser cooling. But cooling atoms by laser? Although the math and physics are challenging, we can understand the idea and basic mechanism more easily when we introduce three basic concepts first: quantum absorption of energy, the Doppler effect, and how atomic motion correlates with temperature. The Absorption of Energy "Quanta" It is at the very heart of the quantum theory that an electron bound in an atom cannot absorb just any amount of energy it encounters. In the free state, it can, but as soon as the electron is restrained as part of a new structure in an orbital, only certain discrete amounts of energy…
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Electroforming Copper Feedhorns Using Aluminum Mandrels

Chemistry, Technology
[caption id="attachment_24084" align="alignright" width="480"] Copper electroforming bath, with growing electroforms and bagged anodes. Pump and continuous bath filtration are essential, though they are not shown for clarity.[/caption] The electroplating laboratory technician may be asked to grow a metal object from scratch, rather than merely plate an existing part. The result, before final external machining, is called an electroform. Electroforming involves much more than merely plating a long time. Critical issues need to be addressed to ensure success. While electroforming involves science, it is truly an art. Definitions and Basics [caption id="attachment_24085" align="alignleft" width="300"] A microwave feedhorn is similar to an old-fashioned ear trumpet. Image National Archives.[/caption] Microwaves are electromagnetic waves with a wavelength in the range of 0.001–0.3 meters. When creating a microwave feedhorn via electroforming, the scientist will grow…
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Diamondoids: Adamantane, Diamantane and Triamantane Practical Uses?

Chemistry, Technology
Carbon readily bonds to itself. This unusual characteristic allows the existence of a whole host of hydrocarbons, some of which assume amazing geometric shapes. Cyclopropane (C3H6) looks like an equilateral triangle. Cubane (C8H4) is a cube. In recent years, Bucky balls, graphene sheets and nanotubes have become household topics. Diamondoids Diamondoids are compounds of hydrogen and carbon consisting of cage-like structures that resemble the diamond lattice. Carbon-carbon bond lengths are 1.54 Ångstrom units (1 Å = 10-8 centimeters) in length both for diamond and for diamantane. But the structures themselves are difficult to compare. Please take some time to ponder the unit cell image for diamond and the chemical structures of the first three diamondoids of the series, adamantane (C10H16), diamantane (C14H20), and triamantane (C18H24). Diamondoid to Diamond? Diamond is…
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