So given these conditions, it will come as no surprise that researchers led by Peter McGrail out of the Pacific Northwest National Laboratory have been working a new porous nanomaterial that improves an existing process used for refrigeration and air conditioning called adsorption chilling.

Image courtesy colmaccoil.com

All refrigerators and air conditioners make the environment cooler by creating phase changes in a refrigerant so that the chemical absorbs heat.  Most familiar air conditioners use electrically driven compressors to mechanically compress the vaporized refrigerant, whereas adsorption chillers use heat to condense the refrigerant. Evaporated refrigerant “adheres to a surface of a solid, such as silica gel. The silica gel can hold a large amount of water in a small space—it essentially acts as a sponge for the water vapor. When the gel is heated, it releases the water molecules into a chamber. As the concentration of water vapor in the chamber increases, the pressure rises until the water condenses” (Bullis). When that happens, heat is absorbed out of the environment and the newly cooled people rejoice!

Image courtesy emissionless.com

Historically, bulky adsorption chillers have been more expensive and far less efficient to operate than chillers that use electrical compressors.  The flip side is that they are cheap to operate and, if you’re an industrial facility or power plant manager who has massive quantities of waste heat lying around, you can practically run them for free. That’s right people: absolutamente GRATIS.

The new material will make it easier to cool smaller buildings with solar water heaters or waste heat from generators by shrinking the hulking adsorption machines by 75% in size and cutting associated costs in half (Bullis).  Size and cost reductions could make adsorption chillers competitive with compressor driven chillers.

The researchers’ nanomaterial consists of “nanoscopic structures that self-assemble into complex three-dimensional shapes. It’s more porous than silica gel, with a larger surface area for water molecules to cling to. As a result, it can trap three to four times more water, by weight, than silica gel, which helps reduce the size of the chiller” (Bullis). The other interesting thing about the material is that it forms weak bonds with water molecules.  This is a good thing because it means less heat is required to free the molecules (or other refrigerants), making the process of adsorbing and desorbing water 50-100 times faster.

While the nanomaterial definitely makes adsorption chilling more attractive, it’s tricky to match the demand for cooling with the production of heat. For example, if you needed to run the chiller when the sun had set because you lived somewhere humid, you might need a heat storage system (and those can be expensive). Still, anytime things get more efficient a little fairy creature gets some wings!

WU XING:

Cited:

Bullis, Kevin. “Using Heat to Cool Buildings.” Technology Review Online. 03/30/11. Accessed 06/29/11. URL.

Image courtesy todayifoundout.com

A fascinating new metal alloy material under development by researchers at the University of Minnesota, led by Professor Richard James, works similar to a generator, producing electric current in the presence of heat energy.

Ni45Co5Mn40Sn10 is a composite of nickel, cobalt, manganese and tin that is multiferroic (has both magnetism and ferroelectricity, yeilding permanent electric polarization).  The alloy “undergoes a reversible phase transformation, in which one type of solid turns into another type of solid when the temperature changes…. Specifically, the alloy goes from being non-magnetic to highly magnetized. The temperature only needs to be raised a small amount for this to happen” (Boyle).  So when you heat this stuff up and place it near a permanent magnet (perhaps a rare-earth magnet) the alloy’s magnetic force increases with all the dramatic intensity of Joan Crawford, producing a current in a nearby coil.

Image courtesy popsci.com

A process called hysteresis, which makes me imagine sixteen distraught women in togas running down the street screaming, crying, and tearing their hair out, causes a small fraction of the heat energy to be lost. Despite all the hysteresis, researchers believe the alloy could be used to convert waste heat energy into large amounts of electricity. Cha ching!

Auto manufacturers are currently working on heat transfer devices that can convert hot car exhaust into useable electricity.  General Motors has been looking at alloys called “skutterudites” made from cobalt-arsenide materials “doped with rare earths” (Boyle). The material could also be used to make heat-capture devices that could be placed near the rare earth magnets in hybrid car batteries, or used for power plants or even ocean thermal energy generators, according to the researchers.

WU XING:

I have filed this post under Metals due to the prevalence of the alloys and the metals and whatnot.

Cited:

Boyle, Rebecca. “New Alloy can Convert Heat Directly into Electricity.” Popsci. 06/22/11. Accessed 06/24/11. URL.

Image courtesy thenewyorkgreenadvocate.blogspot.com

The Lumenatrix Backlighting System by Duo-Guard aims to remedy at least the energy consumption issue by providing an LED-based architectural lighting system that allows designers to create free standing, smoothly illuminated architectural elements such as walls and ceilings without hot spots.

The Lumenatrix system is comprised of tiles (squares, hexagons, octagons, or rounds that can be custom-fabricated in 2″-12″ depths) supplied individually or in prearranged configurations.  The tiles can be recessed, surface, or pendant mounted, and they’re capable of transmitting daylight, which reduces the cost of a glowing wall during daylight hours.  The tiles are arranged in panels that consist of a structural power rail grid system that provides low voltage electricity to the LEDs.  The lights can slide on the rails to produce specific lighting effects.

Image courtesy thenewyorkgreenadvocate.blogspot.com

Heat sinks allow the system to run at lower temperatures, which theoretically increases the lifespan of the LED bulbs, and with one LED per square foot of illuminated surface, the power consumption of the system can be as low as 1-3 watts per square foot.

Check out the following video produced by Duo-Guard for Greenbuild last year to learn more about the system!

WU XING:

I have filed Lumenatrix Backlighting system under Fire, since it involves lighting.

Cited:

Lumenatrix Site

Scientists have been working with carbon nanotubes (essentially, rolled up sheets of graphene) to encourage solar cells to convert more of the sun’s energy to electricity.  Theoretically, nanotubes “gather more electrons that are kicked up from the surface of a PV cell, allowing a greater number of electrons to produce a current” (Boyle).  More electrons means more power, so it’s a decent line of research to pursue.

image courtesy roselawgroup.com

In practice, however, using carbon nanotubes in solar cells has proved more complicated than one might like for two reasons: “first, the making of carbon nanotubes generally produces a mix of two types, some of which act as semiconductors (sometimes allowing an electric current to flow, sometimes not) or metals (which act like wires, allowing current to flow easily). The new research, for the first time, showed that the effects of these two types tend to be different, because the semiconducting nanotubes can enhance the performance of solar cells, but the metallic ones have the opposite effect. Second, nanotubes tend to clump together, which reduces their effectiveness” (Chandler). Understanding the differences between the two types of nanotubes could be useful for designing more efficient nanoscale batteries, piezoelectrics or other power-related materials.

Image credit Matt Klug, Biomolecular Materials Group

Graduate students Xiangnan Dang and Hyunjung Yi, MIT professor Angela Belcher and colleagues turned to biology for a solution to these nanochallenges, employing a genetically engineered version of a virus called M13, prone to attacking and infecting bacteria.  M13 can arrange and order nanotubes on a surface.  The virus has peptides that bind to the nanotubes, allowing them to separate the tubes so they can’t short out the circuits, and it also prevents clumping. “Each virus can grip about five to 10 nanotubes each, using roughly 300 of the protein molecules. The viruses were also genetically engineered to produce a layer of titanium dioxide, which happens to be the key ingredient in Grätzel cells, a.k.a. dye-sensitized solar cells… This close contact between TiO2 nanoparticles helps transport the electrons more efficiently” (Boyle).

Interestingly, the viruses also make the nanotubes water-soluble, which could lower manufacturing costs by facilitating the incorporation of nanotubes into solar cells at room temperature.  The virus-built structures enhanced the solar cells’ power conversion efficiency to 10.6 percent from 8 percent. That’s about a one-third improvement, using a viral system that makes up just 0.1 percent of the cells’ weight (Boyle). A little help from biology goes a long way.

WU XING:

I have filed this under fire, because the main idea relates to energy.

Cited:

Boyle, Rebecca. “MIT Researchers use Viruses to Build More Efficient Solar Panels.” Popsci.com 04/25/11. Accessed 04/26/11. URL.

Chandler, David L. “Solar Power Goes Viral.” MIT News Office. 04/25/11. Accessed 04/26/11. URL.

Image courtesy mirror.uncyc.org

In the case of Frankenstein’s monster, manufacturing a human being out of various other people resulted in the production of a highly unfortunate, eight-foot tall murderer. Mary Shelley was a little bit ambigous about the process (with good reason) but it’s clear that however it was accomplished, the manual combination of different human beings does not produce a new person who embodies the best characteristics of each of his constituent parts.  Thankfully, this is not the case for materials.  In fact, combining different materials often results in improved products that leverage the best qualities of their components; the strength of one material compensates for the weakness of another, and vice versa.

Wood appears to be a willing partner in many composite material ventures: last week I wrote about woodwool cement (read more here) and this week I am featuring TimberSIL GlassWood, which is wood that has been infused with glass.  More specifically, the wood is bathed in liquid Sodium Silicate, “comprised of microscopic particles of glass in an aqueous solution” (TimberSIL). Glass is a surprisingly strong material in compression, although it is brittle and shatters easily when subjected to tensile forces.  Wood, on the other hand, is weaker, but it makes up for that deficiency by being flexible. 

Image courtesy Treehugger

Sodium silicate consists of “a mixture of sand and soda ash used since the 1800s in detergents and as an egg preservative. Lumber soaks in it under pressure, then bakes until an insoluble matrix of amorphous glass hardens throughout the wood. It makes the wood highly resistant to rain, bugs, and general wear. It costs $4.50 per 8-foot 2×4.” (Thomas).  The glass layer surrounds and fuses with wood fibers, greatly increasing their strength and allowing nails, screws, and other fasteners to bite in more effectively. 

The glass keeps the wood from warping because it blocks the absorption of moisture, and it also acts as a fire retardant.  It renders the wood less pervious to traditional attackers (rot and decay, termites, fire, etc). The glass barrier is permanent, non-toxic, and non-corrosive, and since GlassWood lasts longer than regular wood, it requires replacement much less often (TimberSIL).  The product accepts stain and can be cut and sanded like conventional wood. 

TimberSIL takes wood to the next level by fusing it with glass.  And in contrast with Frankenstein’s monster, it doesn’t terrorize people all over the countryside with its appearance and subsequent random acts of violence, nor does it moan on and on about how it has been rejected by its creator. 

WU XING:

I have filed GlassWood under wood, for obvious reasons.

Cited:

http://www.timbersilwood.com/

Thomas, Justin. “Popular Science’s Best of What’s New: TimberSIL.” Treehugger.com 11/13/05. Accessed 03/29/11. URL.

Image courtesy physorg.com

Energy start-up NextGen thinks their solar paint has the potential to go 100,000 miles without batting an eye (so to speak).  Their “new breed of cheap solar paint is closer than ever now that the company has raised half of the $1 million it needs to move out of the lab and into the real world. The company’s solar paint is expected to provide up to 40% efficiency at a third of the cost of traditional photovoltaic panels. That’s partially because the paint captures more wavelengths of light than traditional cells. The material, which forms small connected solar cells as it dries, can be applied to nearly any surface–windows, walls, roofs, and more” (Schwartz). It would be easy to repair damaged paint too – you’d just apply another coat.

Image courtesy gliving.com

NextGen isn’t the only organization working on solar paint and spray-on solar cells; others include the National Institute of Standards and Technology, the University of Texas, and the National Renewable Energy Laboratory (Schwartz).  At UT, a research group is making nanocrystals out of copper, indium, gallium, and selenide, dispersing small particles of the inorganic material in a solvent to create an ink or paint that can be sprayed on plastic, glass, and even fabric to create a solar cell. Nanocrystals and nanotubes 10,000 times thinner than a strand of human hair absorb a larger number of light wavelengths onto the photovoltaic cell. The paint can be applied to almost any surface and once dry hooks into the light-sensitive grid to start pumping out electricity (Stefano).

Image courtesy homepage.mac.com

Solar paint technology would be a good fit for something like a government buildings where solar paint could offset energy consumption while giving taxpayers a break, but it should be noted that solar paint is still bleeding edge and “has yet to prove itself in a commercial setting. But if it is successful, NextGen’s paint could help reach the elusive goal of bringing solar power down to price parity with coal power” (Schwartz).  Another issue researchers face is finding raw materials can be used if this technology can be mass produced; copper, indium, gallium, and selenide are not particularly cheap nor are they readily available. Challenges acknowledged, I have a feeling that if this works out we’ll all be slathering our homes and businesses with solar paint and selling energy back to the grid. Then we’ll all go out and buy Lamborghinis.

WU XING:

While it seems somewhat paradoxical, I have filed solar paint under FIRE because it generates electricity, and under WATER because it is a coating.

Cited:

O’Brien, Miles and Marsha Walton. “Getting a Charge out of Solar Paint.” Physorg.com 02/14/11. Accessed 02/16/11. URL.

Stefano, Greg. “Nano Solar Paint: Liquid cells potentially reinvigorate solar power industry.” Coolhunter.com 09/30/10. Accessed 02/16/11. URL.

Schwartz, Ariel. “NextGen Announces Cheap Solar Paint on the Horizon.” Inhabitat.com 04/12/10. accessed 02/16/11. URL.

Every once in a while I like to find out about a new way to use a very old material, like brick for instance. Human beings have been working with brick at least since the times when the flooding of the Euphrates might engender the total destruction of the walls Gilgamesh built around his city, so the material definitely qualifies as ancient.  And I found out about a rather interesting way that a Dutch company, Tiger Stone, has been laying brick: they are rolling roads out like carpet.

I have no idea why the company is called Tiger Stone, since they manufacture neither stones nor tigers.  They produce machines that can enable three men to pave a 6 meters-wide street without bending over.  The machine moves slowly and quietly on an electrical crawler – it’s not in any way remotely like a tiger.  Well, I suppose that it has some black and yellow stripes painted on it so maybe that’s where the name came from. Apparently there is also a gemstone called a tiger stone, which according to one hastily googled website encourages the following attributes, which admittedly seem much more appropriate: patience, focus, determination, moving slowly, and alertness.

Image courtesy www.psfk.com

Image courtey www.siddhshree.com

What is amazing about the machine is that it paves the entire street, from curb to curb including edge finishing, and it only takes five minutes to learn how to operate. Tiger Stone uses gravity to lay the bricks, which land directly in a pattern on the road. The road is immediately finished.  Sensors detect and follow the curbs and the size of the road is adjustable, so that paving less than six meters wide can be laid.

Workers walk behind the machine loading bricks according to pattern.  The shelf is at waist height behind the machine, so the people who are paving the road never bend down to pick up any bricks.  Bricks are moved over to the Tiger Stone using mini-loaders, and then people hand-place them in the top of the pusher.

Images courtesy Tiger Stone

The machine allows one to three workers to lay at least 300 square meters in one day, whereas a conventional paver lays about 75.  I like that roads paved with bricks are permeable to water, so they reduce runoff, and I think roads installed with masonry units tend to look quite nice.  I recently heard somewhere (read: just made this up) that in the Netherlands there are strict rules about recycling building materials, so the fact that reclaimed brick could be used to build roads out on the polders probably provided the inspiration for this machine.

WU XING:

I’ve filed this machine in the Earth category because it deals with bricks, which are made from earth, more or less, like most things if you think about it.

Cited:

http://www.tiger-stone.nl/

Sometimes when you’re really mad and you’re an adult, you just want to throw something on the ground and smash it to smithereens in order to vent your frustration with “the system”.  In fact, in the United States each year 300 million tires are thrown on the ground by adults of both genders.  Some of these tires are then buried under other trash and discarded objects in landfills, and some of them are sheepishly picked up again and burned for fuel in cement kilns.  For a long time, throwing tires on the ground has lacked the pizazz of say, throwing a highball glass full of scotch into a fireplace in a fit of pique (not that I did it). 

Image credit http://library.thinkquest.org/

What happens when you throw a rubber object on the ground is that it bounces once or twice, flexes a little, and then settles down quietly in its new location.  There are no smithereens, which is a shame given that the real satisfaction of throwing something on the ground comes from producing quality smithereens.  Not only is it unfun to throw, used rubber is unfun to recycle because it is “vulcanized–hardened and rendered chemically inert–by the addition of sulfur and other compounds to the material’s long molecular chains. Small chunks of used tires can be partially melted and used as filler in asphalt, but devulcanizing rubber involves expensive chemical and thermal processes” (McKenna).  And once it’s vulcanized, rubber attempts to live by reason and logic and gets completely out of touch with its emotions.

Enter Lehigh Technologies of Tucker, GA, a company developing a process of smashing old tires in a manner that gives much more satisfaction.  They shatter used tires “into a fine powder using a process that involves freezing old rubber and smashing it to pieces. This starts with tires that have been torn into half-inch chunks using conventional shredding equipment. Lehigh mixes these rubber pieces with liquid nitrogen, cryogenically cooling the rubber to -100°C. The rubber is then fed into a high speed ‘turbomill’ that shatters it into particles no more than 180 microns in size” (McKenna).  The cryogenic shatter-fest vastly increases the surface area of the rubber – transforming it from inert filler material to something special with new properties (such as the ability to bond with other materials). 

Image credit Technology Review

It should be noted however, that Lehigh rubber is in no way devulcanized, which means that carbon atoms in the rubber are still bound to sulfur atoms.  This prevents the atoms from forming covalent bonds with surrounding materials.  To address the shortcoming, Lehigh “opened an in-house research center seeking to change the chemical properties of powders it produces….  The company has also developed ways to make recycled rubber bind to surrounding materials via noncovalent, intermolecular bonds” (McKenna).

The rubber powder made from old tires should open up new recycling opportunities, and Lehigh Technologies has opened a commercial facility with capacity to produce 100 million pounds of powder from four million tires per year.  They recognize that there could be a billion-dollar market for high-performance recycled rubber (McKenna).  But remember, you can’t trust the system!

WU XING:

Rubber is filed under the wood category, but because this is a frozen, pulverized kind of rubber I thought about putting it in the earth category as well.  I decided against it, because I’M AN ADULT.

Cited:

McKenna, Phil. “New Life for Old Tires” Technology Review 04/20/10. Accessed 05/11/10.  URL.