The Chempics team saw this group of crystals on the Instagram feed of Durham University PhD student Rob Ives and wanted to know more. The compound is Cucurbit[6]uril, and it’s part of Ives’s graduate work on “nonconvalent control of shapeshifting molecules,” he says, adding mysteriously, “that’s all I can really say for now, I’m afraid.” A little digging reveals the satisfyingly symmetrical structure for Cucurbit[6]uril shown. Well, Rob, you’ve piqued our curiosity! — Craig Bettenhausen
Credit: Rob Ives, Durham University (@rob_ives on Instagram)
It’s not magic, it’s acoustic levitation. The two metal probes emit and reflect sound waves that trap this liquid droplet in midair. Franziska Emmerling uses the effect to study crystallization without interference from container walls, which can influence the rate of crystal formation (Cryst. Growth Des. 2014, DOI: 10.1021/cg501287v). “In a typical experiment, we use an under saturated solution of a certain compound,” she says. “During the experiment, solvent evaporates from the droplet and the saturation level increases leading to nucleation and then crystallization.” In this photo, however, they’re just levitating blue ink to demonstrate the apparatus.
Emmerling (@FranEmmerling) submitted this photo as part of the #RealTimeChem photo contest on Twitter. The two runners-up in the Reactions category were Henry Powell-Davies (@hpowelldavies) with his balloon reaction and the Townsend lab at Vanderbilt (@Townsend_Lab) with a well-composed flask shot.
Credit: Courtesy of Franziska Emmerling
Do science. Take pictures. Win Money. Enter our photo contest here.
Ozone is a problematic air pollutant that causes serious health problems. A newly developed material not only quickly and selectively indicates the presence of ozone, but also simultaneously renders the gas harmless. As reported by Chinese researchers in Angewandte Chemie, the porous “two-in-one systems” also function reliably in very humid air.
Ozone (O3) can cause health problems, such as difficulty breathing, lung damage, and asthma attacks. Relevant occupational safety regulations therefore limit the concentrations of ozone allowable in the workplace. Previous methods for the detection of ozone, such as those based on semiconductors, have a variety of disadvantages, including high power consumption, low selectivity, and malfunction due to humid air. Techniques aimed at reducing the concentration of ozone have thus far been based mainly on activated charcoal, chemical absorption, or catalytic degradation.
A team led by Zhenjie Zhang at Nankai University (Tianjin, China) set themselves the goal of developing a material that can both rapidly detect and efficiently remove ozone. Their approach uses materials known as covalent organic frameworks (COFs). COFs are two- or three-dimensional organic solids with extended porous crystalline structures; their components are bound together by strong covalent bonds. COFs can be tailored to many applications through the selection of different components.
When one of Eric Täuscher’s PhD students arrived at the lab one morning and discovered she had left a TLC plate in an iodine chamber overnight, she could have simply thrown it out. But something compelled her to take a close look at the neglected plate. When she did, she noticed the tiny crystals growing from the plate, the product of the iodine in the chamber reacting with the plate’s aluminum backing. The crystal growth had also caused the silica on the front of the plate to lift off in delicate flakes. Intrigued, she showed it to Täuscher. He also found the corroded plate strangely beautiful, so he snapped a photo.
Täuscher’s lab at the Ilmenau University of Technology studies fluorescent organic molecules for pH, temperature, and ion sensing applications. The student had been running the TLC to try and identify a mysterious non-UV-absorbing byproduct of a reaction. It took her all of ten minutes to redo the plate. — Brianna Barbu
Computers may be growing smaller and more powerful, but they require a great deal of energy to operate. The total amount of energy the U.S. dedicates to computing has risen dramatically over the last decade and is quickly approaching that of other major sectors, like transportation.
In a study published online this week the journal Nature, University of California, Berkeley, engineers describe a major breakthrough in the design of a component of transistors—the tiny electrical switches that form the building blocks of computers—that could significantly reduce their energy consumption without sacrificing speed, size or performance. The component, called the gate oxide, plays a key role in switching the transistor on and off.
“We have been able to show that our gate-oxide technology is better than commercially available transistors: What the trillion-dollar semiconductor industry can do today—we can essentially beat them,” said study senior author Sayeef Salahuddin, the TSMC Distinguished professor of Electrical Engineering and Computer Sciences at UC Berkeley.
1. The American Edward Goodrich Acheson heated a mixture of clay – aluminium silicate, and powdered coke (carbon) in an iron bowl with a carbon arc, and found shiny hexagonal crystals attached to the carbon electrode. Acheson eventually patented this method for producing powdered silicon carbide (SiC), a compound of silicon and carbon in 1893.
2. The mineral form of silicon carbide is called moissanite and gets its name from Dr Ferdinand Henry Moissan, who first discovered it in the Canyon Diablo Crater in Arizona in 1904.
3. Silicon carbide crystals can be strongly birefringent, meaning the crystals exhibit different refractive indices down different axes.
4. SiC powder production involves the Acheson resistance furnace, produced by the Lely Process. This method creates large single crystals by sublimating silicon carbide powder to form a high-temperature species called silicon dicarbide (SiC2) and disilicon carbide (Si2C).
5. Semiconducting silicon carbide first found application as a detector in early radios at the beginning of the 20thCentury.
To find out more about the history of silicon carbide, read Anna Ploszajski’s Material of the Month feature in our January issue.
Working on polishing my samples for reflective light microscopy. This sample is a pyroxenite from Hogen Camp Mine in the Hudson Highlands region of New York. The area was once a lead producer of iron ore and magnetite for the east coast.
Alkali Feldspar crystals are large in this thin section. The alkali feldspar have subhedral crystals. The quartzy matrix in some areas is intergrown at the edge of the alkali feldspar crystal faces. The muscovite crystallized in the interstitial space and have anhedral crystal faces. To differentiate between the muscovite and the biotite pleochroism comes into effect. The biotite is darker amber under PPL and muscovite is tan/light brown. Both are pleochroic under PPL.
This rock is predominantly composed of quartz, alkali feldspar, and plagioclase. The alkali feldspar grains are large and take up a decent amount of the slide. The perthite is mainly one grain that is large and is about 11mm. The plagioclase has polysynthetic twinning.The muscovite is pleochroic under PPL and has clinopyroxene embayed in the core. Clinopyroxene is present because the melt reacted with the clinopyroxene and create muscovite. Leucite is also present in a minimal quantity. The leucite is embayed in the alkali feldspar. This happened when the alkali feldspar started to crystalize. The silica content was too great and the leucite reacted with the melt to form alkali feldspar. Due to the composition the rock would just be classified as a granite. (leucite in 2nd pic)
Composition includes: biotite, muscovite, chlorite, feldspars, oxides, and quartz. Feldspar poikiloblasts with inclusions of quartz and oxides are prominent throughout much of the sample. Most poikiloblasts occurred synkinematic to the 1st deformation event (D1) and rotation occurred. D1 had a direct effect on the foliation (S1) of minerals that already crystallized. D2 led to crystallization of quartz which is seen in quartz ribbons and pressure fringes throughout the sample.
This thin section shows an amygdule in a sample of amygdaloid basalt. The rock formed due to an eruption of gaseous, low viscous magma which resulted in vesicles throughout much of the rock. The rock then underwent hydrothermal alteration and low temperature alteration minerals formed in the once vesicles, forming amygdules. The amygdules are composed of quartz, celadonite (a type of mica) and epidote.
Folk Names: Aerolith, Aerolite Energy: Projective Planet: none, meteorites are associated with the Universe Elements: Akasha, Fire Deity: The Great Mother Associated Stones: Peridot, Diamond Powers: Protection, Astral Projection
Magical/Ritual Lore:
Meteorites have long been held in fascination by humans. They have been thought to be gifts from the gods and goddesses. Certain meteorites, such as the Kaaba stone in Mecca and a stone thought to represent the Great Mother Goddess of Phrygia, have been worshipped as symbols of divinity.
A four-ton stone has been revered in China as a holy object since the 1200’s. The stone, shaped like a crouching ox, resides in a Bhuddist shrine. Recently, however, a team of Chinese geologists studied
the stone and determined it to be a meteorite that landed about 1,300 years ago. The stone is no longer worshiped. In Babylon the meteorite was a powerful magical protectant. It was thought to remove all evils due to its strange appearance and the "roar of its awful might.“
Peridot is often found in meteorites. I held a small cut meteorite recently and studied the green peridot crystals that were packed inside it. The stone was worth about $3,000, so it didn’t go home with me. Recently, tiny diamonds were found inside meteorites that fell in Mexico in 1969-the first discovered that had formed off of our planet.
At one place or another on Earth, meteorites were used to explain the origin of life. If rocks fell to the earth from space, so too could plants, water, animals and people.
Symbolically, meteorites can be viewed as the spiritual penetrating the physical, as astral power, divine order or whim, though a friend of mine says they’re the melted remains of spaceships from distant galaxies!
Magical Uses:
Meteorites are unearthly things, literally. They possess the powers of intergalactic flight, of movement, of speed, and of energy unhindered by gravity.
Use them in rituals of protection. Place one on the altar near white candles; or carry in the hand.
They are also called upon to promote astral projection. A small meteorite or a fragment of one is placed beneath the pillow during attempts at conscious astral projection.
Yes, they are available for sale at reasonable prices. I visited the Reuben H. Fleet Space Theatre’s gift shop in San Diego a few days ago and found small meteorites for $3.00.
[Source: Cunningham’s Encyclopedia of Crystal, Gem, & Metal Magic by Scott Cunningham]
