CI's Student ACS Chapter Receives National Recognition

CSUCI students received national recognition this year at the ACS meeting in Denver. 

The American Chemical Society national meeting is one of the largest scientific conferences of the year, representing over 10,000 topics ranging from astronomy to zoology. 

Members of the Free Radicals with
Phil Hampton Ph.D, the faculty advisor for the group

The CSUCI student chapter of the ACS, called the Free Radicals, received an award in acknowledgement of their involvement in science outreach programs, such as the annual Science Carnival, as well as their high student participation.

Undergraduate involvement in research and in the scientific community is a high priority for faculty at CSUCI. In order for students to get a feel for how scientists work in the real world, it is imperative for them to get a first-hand experience. Trips to meetings such as these are one of many ways that this is accomplished.

The meeting mostly focuses on the original research of those scientists in attendance. Presented on posters, in slideshows and in presentations, attendees not only learn about the most cutting-edge research ongoing today, but are given a chance to network with those conducting it. 

Oscar Santillan, an undergraduate involved in research focused on electrochemical materials, was one of the eight CI students in attendance. “The topics I followed were chemistry of materials and electrochemistry. In particular, the overlap of the two was of the greatest interest to me. They not only covered topics I find deeply intriguing, but also did so with concision and clarity.”

Corie Hill and Amber Kramer, seniors at CI, presented their research on mercury concentrations in seafood.  

“It was an incredibly valuable experience,” said Corie, “being able to engage with chemistry from around the world, hear cutting edge chemistry lectures and meeting other students who are at my level as well.”

“I took away how diverse and vast the field of chemistry is. There are so many institutions that come together in the name of chemistry: Industry, government and academia and everything in-between. ... It’s incredible to see the level of detail put into the event.”

Besides serving as a window into the details of ongoing research, the ACS meeting serves to broaden the scientific horizons of those in attendance. Students may discover areas of study that they otherwise would never have known about, and perhaps most importantly, meet and talk to the people involved in those areas. Ultimately, science is a social undertaking, and events such as these facilitate the meeting of minds and ideas, which fosters the birth of insight so crucial to any scientific discipline.

Written by Aisling Williams

Liquor Serves as a Good Substitute for HPLC Solvent

A recent study looking into alternative solvents for HPLCs has discovered a rather surprising candidate -  liquor store spirits.

As far as chemical analytical tools go, HPLCs are among the most useful and widely utilized. Enabling chemists to separate mixtures, identify their components and determine their relative abundance, high-pressure liquid chromatographs are indispensable in labs around the world.

Unfortunately, these machines have their drawbacks. They require vast quantities of expensive solvents to run, which must be disposed of as hazardous waste. In 2009, the price of the most commonly-used solvent, acetonitrile, skyrocketed. Chemists seeking reprieve then turned to HPLC-grade ethanol.  Unfortunately, this too can cost as much as $120 per liter.

The machines are becoming more universally accessible due to improvements in technology and manufacturing. Naturally, the next step should be making the eluents more accessible as well. The researchers at Merck Research Laboratories combined various liquors with store-bought ammonia and white vinegar. 

Other than grain alcohol, the drinks tested included rum, vodka, cachaça, and aguardiente. The eluent was then used to separate a mixture of five compounds—uracil, caffeine, 1-phenylethanol, butylparaben, and anthracene—in a conventional HPLC instrument.

The low-cost mixtures performed surprisingly well. Grain alcohol performed about as well as HPLC-grade ethanol in some cases. While lower-proof spirits tended to produce poorer separation, the results were reasonable, especially with more polar analytes. 

Source

Cooney, Catherine M. "Liquor-Store Spirits Provide Green Alternative To HPLC Solvents "Chemical & Engineering News (2015): n. pag. 17 April 2015. Web. 28 April 2015. 

New Type of Chemical Bond Discovered

In 1989, researchers investigating the properties of exotic atoms discovered something entirely unexpected. Under certain circumstances, the rate of a reaction paradoxically sped up as temperature was decreased. This peculiar behavior was found to occur between Muonium, an exotic form of hydrogen made up of an antimuon and an electron, and bromine. Muonium’s behavior with other elements, such as chlorine and fluorine, were more well-behaved; the reaction rate sped up as temperature increased, exactly as expected. Bromine, however, represented a bizarre exception.

In order to explain this mystery, scientists proposed a model where the lighter atom formed a new sort of structure where it was flanked by two heavier atoms, a structure that would be held together not by normal forces but by a new sort of ‘vibrational’ bond.

Credit: Flemming et. al.

"In this scenario, the lightweight muonium atom would move rapidly between two heavy bromine atoms, 'like a Ping Pong ball bouncing between two bowling balls,' Fleming says. The oscillating atom would briefly hold the two bromine atoms together and reduce the overall energy, and therefore speed, of the reaction.”

Due to the exceedingly short lifespan of muonium, it was impossible at the time to investigate this idea in very much depth. But with recent technological developments, it finally became possible to answer this question with certainty. The researchers took the question to nuclear accelerator at Rutherford Appleton Laboratory in England. 

There, they watched the microscopic interplay unfold, and confirmed the new type of chemical bond. It is hypothesized that this exotic new bond may take place between a variety of ultra-light and heavy atoms. Although this new interaction is exceedingly brief, their discovery represents an important development in our understanding of atomic-scale physics and the chemical world.

Sources

Nordrum, Amy. "Chemists Confirm the Existence of New Type of Bond." Scientific American Feb 2015. Web.

New Research Rewrites Understanding of Explosive Alkali Metals

Despite being a staple demonstration in many introductory chemistry classes, the classic explanation for the explosive reaction between alkali metals and water has long been incorrect.

Many middle and high school students are familiar with the demonstration. Almost immediately following contact with water, alkali metals such as sodium and potassium produce a brilliant and highly energetic explosive pop. Instructors the world over would often confidently follow by explaining that the  reaction produces hydrogen gas, whose subsequent ignition is responsible for the theatrics.

However, recent research published in Nature Chemistry shows that things are not actually so simple. Although the hydrogen gas may indeed eventually ignite, the initial rapid explosion is caused by something almost entirely unrelated.

In retrospect, it seems obvious that there was something wrong with the orthodox explanation. In order for a reaction to produce an explosion, the reactants would have to mix very effectively in order to react rapidly and release energy suddenly. This is why flour mills are so susceptible to explosive outbreaks of fire; a build-up of finely ground flammable particles suspended in the oxygen-rich air allows any spark to consume an enormous amount of fuel virtually instantaneously.

Alkali metals, on the other hand, are solids. The water can only come into contact with the outer surface, which should result in a brief layer of products preventing it from reaching deeper layers right away. Water isn’t immediately in contact with every metal atom, so at the very least the reaction should proceed more slowly than it does.

In order to investigate this further, researcher Pavel Jungwirth and others set out to scrutinize the reaction with the use of high-speed cameras. Because pure alkali metals tend to accumulate an oxidized layer on their outer surfaces, causing them to be less reactive in water, he used an alloy of sodium and potassium that is liquid at room temperature.

The images captured by the cameras were very telling. The reaction begins less than a millisecond after the droplet contacts the water. At 0.4 milliseconds, spike-like tendrils of metal shoot outward, much too quickly to have been produced by heat. Most interestingly, this spiked droplet develops a never-before-seen aura of dark bluish purple color in the surrounding solution between 0.3 and 0.5 seconds (see supplemental video). This blue color turned out to be the key to understanding what was really going on.

The origin of this mysterious color was confirmed when Jungwirth’s colleage Frank Uhlig recreated the reaction in a quantum-mechanical simulation. This digital analysis revealed that atoms at the surface of the cluster were each stripped of an electron within just a few picoseconds. The electrons then rapidly shoot away from one another and become solvated in the surrounding solution. Free electrons in solution, as many chemists know, appear blue to the naked eye. The loss of these electrons leaves the atoms positively charged, resulting in an incredibly strong repulsive force blowing the cluster apart.

This research represents a feature of science that keeps so many people fascinated by it. Although it may seem like the basics are well-understood, surprises like this frequently come from the most unexpected of places. Scientific knowledge is highly dynamic and constantly evolving, as nature proves time and time again that the richness and complexity of reality rivals the limits of human imagination.

Written by: Aisling Williams

Source

Mason, Philip E., Frank Uhlig, Vaclav Vanek, Tillmann Buttersack, Sigurd Bauerecker, and Pavel Jungwirth. "Coulomb Explosion during the Early Stages of the Reaction of Alkali Metals with Water." Nature.com. Nature Publishing Group, 26 Jan. 2015. Web. 8 Feb. 2015.

Targeting Cancer Cells with Self-Assembling Molecular Cages

Taking inspiration from nature, chemists have developed a new method to destroy bone cancer cells that utilizes artificial extracellular matrices.

Because extracellular matrices provide support and structure to the cells making up many organs and tissues, their artificial production has been very appealing to tissue engineers. Scientists searching for a method to produce them in the lab have mainly focused on self-assembling peptides.

Cancer cells before (left) and after (right) 7 hours of exposure to self-assembling
carbohydrate molecules.

Credit: J. Am. Chem. Soc.

In order to exploit one of the common features of bone cancer cells, Bing Xu of Brandeis University designed such a peptide with one important modification; it is only capable of self-assembly upon removal of a phosphate group. Once it’s gone, the molecules have a hydrophobic and a hydrophilic end, allowing them to aggregate into films like the lipids that form membranes in the body.

This property made them perfect for targeted destruction of certain types of cancer cells, which produce alkaline phosphatase, an enzyme that removes phosphate, in far greater quantities than healthy cells do.

Another researcher, Rein V. Ulijn of the City University of New York’s Hunter College, took it a step further. Because carbohydrates can produce such a rich diversity of structures, he endeavored to use them in a similar way. 

To create a carbohydrate molecule that would self-aggregate, he attached a hydrophilic glucosamine to a hydrophobic aromatic. Then he added a phosphate group that would interfere with the molecules’ mutual attraction to its peers, thereby postponing the formation of a film until the group was cleaved off, hopefully, near a phosphatase-rich cancer cell.

Subsequent tests investigating the effectiveness of the substance against cancer cells yielded optimistic results. The chemical killed 95% of cultured bone cancer cells, while only 15% of healthy control cells perished after 7 hours of exposure. 

Written by: Aisling Williams

Source

Berg, Erika G. "Self-Assembling Carbohydrates Trap Cancer Cells In A Cage." Chemical & Engineering News (2015): n. pag. 20 Jan. 2015. Web. 27 Jan. 2015.

Crystal Nucleation More Nuanced Than Once Thought

The formation of crystals is paramount to the production of an enormous variety of products we use every day. From things as simple as sugar or salt to revolutionary technology involving crystalline metals and silicon, the understanding of the processes of crystal growth has been a staple of scientific progress. However, recent research indicates that nucleation – the process initiating the growth of a crystal – may be much more complex than previously imagined.

The classical model of crystal growth breaks the process down into two major steps. First, ions or molecules come together into a tiny crystalline seed, on whose structure the properties of the emerging crystal will depend. From that point, other solvated ions fall into place, thereby expanding the lattice and growing the crystal. As the crystal grows, the bulk free energy of the mass decreases; yet at the same time, the solid-liquid interface expands, increasing free energy. Nucleation is officially defined as the point at which the crystal reaches the critical size threshold beyond which the energy benefit of growth exceeds the cost.

However, this model is proving to be inadequate in the face of mounting evidence. There seem to be a variety of different mechanisms from which a crystal structure can emerge. For instance, research done in 2002 at MIT involved inducing crystallization in glycine using laser pulses. By altering the polarization of the incident laser, the group produced a variety of different crystal polymorphs. 

According to MIT Chemical Engineering professor Allan S. Myerson, such a phenomenon indicated that the laser must have been acting on some pre-existing structure that was somewhere in between an ordered crystal and completely solvated molecules.

A more recent study in 2014 visually examined the microscopic behavior of calcium carbonate as it formed crystals. Calcium carbonate represented an interesting substance for such a study due to its tendency to form a wide variety of crystal polymorphs, including calcite, aragonite, and vaterite. While material often appeared to nucleate into any of the three directly, sometimes the molecules would aggregate into unstructured blobs which then transformed into aragonite or vaterite. 

This sort of behavior may be important beyond the formation of the initial crystal ‘seedling’, as it is possible for actual crystal growth to depend on the formation of such viscous blobs. Perhaps individual ions or molecules are incapable of adding to the growing crystal in isolation, and need to first form groups to proceed.

The behavior of real systems appears to be extremely diverse. In the words of James J. De Yoreo, who lead the calcium carbonate study, “Think up any mechanism or pathway you want, and there will probably be some system that behaves that way.”

Written by: Aisling M Williams

Sources

Kemsley, Jyllian. "Illuminating Crystal Nucleation." Chemical & Engineering News93.2 (2015): 28-29. CEN RSS. Chemical & Engineering News, 12 Jan. 2015. Web. 13 Jan. 2015.

6th Annual Science Carnival

On November 1^st, the 6^th annual CSUCI-hosted Science Carnival proved once more to be a roaring success.

Being entirely volunteer-run, the carnival remains free to attend and continues to attract guests of all ages. Students between Kindergarten and 8^th grade, many with siblings and parents in tow, flocked to Thurgood-Marshall elementary school to participate in the festivities.

From Biology and Chemistry to Paleontology and Physics, the carnival provided over 70 dazzling science demonstrations and activities to fascinate and inspire a younger generation.

Students admire a demonstration of UV fluorescent chemicals.

Fire isn't always yellow! This volunteer shows a crowd how the color of a flame
can actually depend on what compound is undergoing combustion.

The high-frequency electromagnetism associated with the plasma filaments in a
plasma lamp can induce a nearby fluorescent lightbulb to light up!

This ball python was one of many animals present at the science carnival.

Angular momentum is a physical phenomenon so rarely encountered that even
adults found this demonstration strange and fascinating.

This ping pong ball cannon made it clear
just how powerful air pressure can be.

This apparatus pumps air in and out of a pair of real lungs!

Many guests were surprised by the rich topography
of the microsocopic world.

Live crabs, starfish and many other marine creatures
made this booth particularly popular.