Tag: Chemistry

Better Living through Chemistry. New research is discovering more sustainable materials and energy sources that can help solve our environmental issues.

Over the last two hundred years the science of chemistry has been so successful in developing new energy sources like coal and oil along with new materials like plastics that it has entirely changed the way people live. Seriously just consider all of the materials around your home that did not exist back in the 1820s and you’ll realize just how successful chemistry has been.

Did you have a Gilbert Chemistry set when you were a kid. I think this is the very set I had! (Credit: Pinterest)

But as the old saying goes, “too much of anything isn’t a good thing,” so that today the ‘scientific miracles’ of a few generations ago are now more trouble than they’re worth. The two biggest problems caused by our success with chemistry are undoubtedly climate change caused by the burning of fossil fuels and the enormous amount of trash being generated by single use plastics.

It just occurred to me that in this Blog I’ve shown a lot of images of exhaust pollutants. (Credit: Clean Wisconsin)
And plastic trash! (Credit: USA Today)

If we’re going to find solutions to these problems then we’re going to need chemists to work on alternative, more sustainable ways of generating power and performing the many tasks to which we put plastic. And in fact such research is being conducted in labouratories around the world this very moment. In this post I’ll discuss some of the results of those efforts.

Right now all over the World Chemists are working hard to find solutions to the problems that ironically they helped to create. (Credit: Pomona College)

Sustainable sources of power, such as solar panels or wind turbines are problematic in that while they produce large amounts of energy at certain times, when the Sun is out for solar panels, they produce very little energy at other times, at night for solar panels. The problem therefore is how to store the energy generated at peak production hours so that it can be used when production is low.

The amount of energy being generated by solar arrays is increasing rapidly but we need a more efficient method of storing that energy. (Credit: KATV)

One method of storing the energy is to use it to split water molecules into their constituent oxygen and hydrogen atoms. Then the hydrogen produced can be stored in gas cylinders for use in a fuel cell to generate electricity at a later time. Unfortunately the process of breaking down water in the first place requires a catalyst and even with the best-known catalysts the method is very inefficient, wasting large amounts of the energy we’re trying so hard to generate.

The basic operation of a fuel cell. Hydrogen and Oxygen go in and Water and Electricity come out. Couldn’t be cleaner! (Credit: Intelligent Energy)

 Now a team of scientists at UVA and the California Institute of Technology along with the US Department of Energy’s Argonne National Labouratory, Lawrence Berkeley National Labouratory and Brookhaven National Labouratory has developed a unique catalyst that they hope will greatly increase the efficiency of the process. Unlike most catalysts, which are simply salts dissolved in the water, the chemists have developed titanium oxide nanocrystals that contain literally zillions of active catalytic sites on their surfaces. These sites operate at the atomic level to trigger what is known as the oxygen evolution reaction that separates the water molecules into their component gasses.

The definition of a catalyst is a substance that takes part in a chemical reaction, usually speeding it up, but is not consumed at the end of the reaction. (Credit: Slideshare)

While the titanium oxide nanocrystals themselves were developed at UVA the Argonne and Lawrence Berkeley Labouratories contributed to the project with the use of their synchrotron X-ray spectroscopy facilities that allowed the chemists to see the catalytic sites in action so that they could more accurately measure their performance.

Nanocrystals are a fascinating new field of study. Chemists have only begun to discover the many uses that they can be put to! (Credit: Researchgate)

The physicists at Cal Tech then analyzed those measurements using newly developed quantum mechanical methods. While large-scale implementation is still in the future the results of this team effort have already advanced the drive toward clean, sustainable energy storage.

And new methods are storing power are urgently needed because the installation of solar panels onto homes, businesses and other buildings is now one of the fastest growing industries in the world. And that growth could become even greater if researchers at Incheon National University in Korea are successful in developing transparent solar cells that can double as windows!

Transparent Solar Panels could be a real breakthrough. Imagine how much more power we could generate if every window produced electricity! (Credit: The Verge)

In order to develop their transparent solar cell the scientists needed to find two semiconductor materials that are clear in the optical portion of the spectrum but will absorb non-visible wavelengths of light in order to capture their energy. It’s at the junction of the two semiconductors that the absorbed light is converted into electricity.

Basic diagram of a solar cell. It’s at the interface of the n-type and p-type materials that the sunlight is absorbed and electricity is generated. (Credit: Energy Education)

The two materials that the researchers, led by Professor Joondong Kim, settled upon are titanium dioxide (TiO2) already widely used in the manufacture of solar cells and Nickel Oxide (NiO). Both are nearly transparent at visible wavelengths but readily absorb ultraviolet (UV) light. And on top of their optical properties both materials are relatively cheap, non-toxic, and environmentally friendly.

Titanium Dioxide is already a very useful chemical and a multi-billion dollar a year industry. Yes, we even eat some of it! (Credit: Food Additives.net)

Think about it, in addition to covering the roofs of buildings with solar panels now all of the building’s windows can add their area to producing more energy, and you know the sides of some of those big office are nearly all window! The amount of electricity generated by solar panels could almost double making a real impact in the drive to eliminate fossil fuels.

Replacing fossil fuels with cleaner, more sustainable energy sources may solve one of our environmental troubles but that still leaves the problem of what to do with all of the plastic we keep producing. It’s a real dilemma because plastic is so very useful that we really do need it. When we dispose of it however, it really doesn’t go away. Plastics can take centuries or more to degrade so all the bags, containers, utensils and almost everything you can think of just keeps on piling up until now they are a major environmental threat. What we need therefore is a material that can replace plastic but which is easily biodegradable.

Doctor Antoine Buchard of the Centre for Sustainable and Circular Technologies at the University of Bath in the UK has been investigating that very possibility. Dr. Buchard’s research centers around the sugar xylose that is readily available in wood and is actually the second most common sugar found naturally, in other words it’s cheap!

Xylose is a sugar and one of the most abundant chemicals in nature. (Credit: Science Direct)

Dr. Buchard has succeeded in using xylose to create long molecular chains similar to those in plastics called polymers. The polymer, which belongs to the family of chemicals known as polyether, can be manufactured as either a flexible or crystalline material. So far the material has shown that it can used to replace both polyurethane and polyethylene but Dr. Buchard hopes to also find entirely new uses for his discovery.

Polymers are simply long chains of smaller identical chemicals like xylose. (Credit: Live Science)

Presently the chemists at Bath are producing the new polymer in small quantities but anticipate that production could be easily scaled up to industrial quantities. Replacing fossil fuel derived polymer plastics with polymers obtained from naturally occurring sugars will go a long way toward reducing the amount of plastic trash that’s choking our planet more and more everyday.

Chemistry got us into these problems by ironically giving us very useful things that we really liked! And chemists are now working hard to find new materials to help solve those very same problems.

The Nobel Prizes for 2019 are awarded.

It’s that time of year again. The Nobel Committee has announced its choices for the award that recognizes achievements in the fields of Physics, Chemistry and Medicine (Physiology). Since my degree is in physics I think I’ll start with the winners for Physics.

This years winners are being recognized for their work in revealing some of the details about the structure of this Universe in which we live. Three scientists, James Peebles along with Michel Mayor and Didier Queloz will share this year’s prize of 9 million Swedish krona or $910,000 dollars.

James Peebles, Michel Mayor and Didier Queloz were awarded the 2019 Nobel Prize in Physics for their work in Astrophysics. (Credit: Bloomberg)

Two of the physicists, Professor Michel Mayor of the University of Geneva along with Didier Queloz, who teaches at both the University of Geneva and Cambridge University were honoured for their discovery in 1995 of the first exoplanet orbiting a Sun like star. Today we know about the existence of thousands of exoplanets but it was Mayor and Queloz who used a technique called the Radial Velocity Method to discover an exoplanet orbiting the star 51 Pegasi, in the constellation of Pegasus.

Looking at the illustration below of a star and its planet both orbiting around their mutual center of gravity we see how the star is sometimes moving toward us and sometimes away from us. This tiny tug back and forth due to the gravity of the planet can be seen in a blue shift in the star’s light as it moves toward us and a red shift as it moves away. It was by detecting a repeating pattern of blue and red shifts in the light of the star 51 Pegasi having a period of 4.2 days that allowed Mayor and Queloz to announce their discovery.

An Illustration of the Radial Velocity Method for discovering exo-planets. (Credit: Johnan Jarnestad/ Swedish Academy of Science)

The work of James Peebles of Princeton University, the Albert Einstein Professor of Physics no less, deals with a topic a bit bigger and older than a mere planet, the birth of the Universe itself. You see Peebles, working back in the 1970s, was one of the leading scientists who put the Big Bang Theory on a solid theoretical basis.

Doctor Peebles work dealt with probing the Cosmic Microwave Background (CMB) for clues about not only the conditions that prevailed in the Universe at the time of the Big Bang but also in the Universe as it is today. The cosmic Microwave Background is the tiny amount of heat left over from the Big Band that permeates the entire Universe and is almost, almost the same temperature everywhere and in every direction.

The Cosmic Microwave Background as seen by the Planck Satellite. The tiny differences in temperature seen here were predicted by James Peebles. (Credit: Universe Review.ca)

It was Doctor Peebles who first predicted that tiny fluctuations in the CMB had to be there. If the CMB was perfectly smooth he reasoned, then the Universe today would also be perfectly smooth, instead of possessing all of the galaxies and stars we see. In other words those tiny variations in temperature 13.8 billion years ago were the seeds from which the structure of today’s Universe grew.

Further analysis of those variations also allowed Peebles to calculate the percentage of the energy of the Universe that today is composed of ordinary matter, the atoms and elementary particles we are familiar with, dark matter and even dark energy which are the subject of so much current research. When you consider how much of our knowledge of the early Universe is due to the work of James Peebles it’s no wonder he has finally received the Nobel Prize.

Since you’re reading this post right now there’s a good chance that you’re using either a smartphone, smartpad, or laptop computer. If so you might want to take a moment to thank the winners of this year’s Nobel Prize in Chemistry. You see the research for which M. Stanley Whittingham, John B Goodenough and Akira Yoshino will share their 7 million krona is the development of the Lithium-Ion batteries that today power our mobile world.

John B. Goodenough, M. Stanley Whittingham and Akira Yoshino received this years Nobel Prize in Chemistry. (Credit: Swedish Royal Academy of Science)

The development took quite a long time and there were more than a few problems along the way to overcome. It began in the 1970s when Stanley Whittingham discovered an energy rich material called titanium disulphide that he used as the cathode, the negative terminal in a battery with a metallic lithium anode as the positive terminal. Whittingham used lithium because of the metal’s ability to release large numbers of electrons.

Lithium Ion Batteries are a fixture in our modern world. (Credit: B&H)

The problem with these early lithium batteries was that each time the battery was recharged there was an internal buildup of chemicals at each terminal. This buildup would continue until the two terminals actually touched each other inside the battery causing a short circuit that released all of the battery’s energy in seconds. The result of that short would be either a fire or even an explosion. Despite this danger lithium batteries were so powerful that they quickly found some limited applications.

The Charge and Discharge mechanisms of a Lithium Battery. (Credit: ResearchGate)

Then in 1980 John B. Goodenough made lithium batteries even more powerful by replacing the disulphide terminal with one composed of cobalt oxide that nearly doubled the energy storage capability. Nevertheless the danger inherent in the lithium battery still kept them from widespread use.

It wasn’t until 1985 that Akira Yoshino succeeded in replacing the metallic lithium with Lithium Cobalt Oxide (LiCoO2) alleviating the buildup of chemicals and making the new lithium ion battery safe enough for widespread use. Thanks to the efforts of these three dedicated scientists the development of the modern lithium ion battery is a case study in how engineering research is carried out, one step at a time. Certainly an achievement worthy of a Nobel Prize.

Also announced this week was the Nobel Prize in Medicine awarded to Doctors William G. Kaelin of Harvard University, Gregg L. Semenza of Johns Hopkins University along with Peter J. Ratcliffe of the Francis Crick Institute and Oxford University. The trio was recognized for their work in understanding how cells adjust their metabolism to match the availability of oxygen.

The 2019 Nobel Prize in Medicine was awarded to William G. Kaelin, Sir Peter J. Ratcliffe and Gregg L. Semenza. (Credit: Swedish Royal Academy of Science)

We are all aware of just how necessary oxygen is for life; the cells of our body will quickly begin to die without that gas. However cells can reduce the amount of oxygen they require whenever oxygen levels become lower. Our bodies experience such reduced oxygen levels during many activities such as swimming or other exercise, or while at high altitude.

More importantly however many people experience low oxygen levels for long periods of time due to lung or heart disease or anemia. In fact the knowledge gained by Doctors Kaelin, Semenza and Ratcliffe is already being put to use to develop drugs that will help patients with those aliments to make better use of the oxygen in their systems and live healthier lives.

For patients suffering with Heart or Lung problems a lack of oxygen is a serious threat. (Credit: Healthline)

The discovery may also be important in the treatment of cancer. You see it has long been known that cancer cells signal other cells in our body to build new blood vessels to them that increases their flow of oxygen enabling the tumors to grow even faster. It is possible that this research may lead to techniques that prevent this increased blood flow thereby slowing the growth of cancerous tumors.

The work of these three Nobel laureates gives our medical science another tool to both fight disease and to understand how living creatures work. Each year the Nobel Prizes are awarded to recognize the best, the most significant discoveries in science. It’s important to remember however that there are many smaller, but still significant advances. All of these discoveries combine to add to our ever increasing knowledge of the natural world. 

Nobel Prizes for 2018, Medicine, Physics, Chemistry.

The first week of October is always an exciting time in the scientific community; it’s when the Nobel Prizes are announced. The order of announcement changes ever year and this year it went Medicine, then Physics and finally Chemistry so I’ll follow that order as well.

The two winners of the 2018 Nobel Prize in Medicine and Physiology are Doctors James P. Allison of the University of Texas M. D. Anderson Cancer Center and Tasuku Honjo of Kyoto University. The research conducted by the two scientists consisted in both understanding why our immune systems refuse to attack the cancer cells that are destroying our bodies along with discovering the first drugs that enable our immune systems to fight cancer.

2018 Nobel Prize Winners in Medicine. Tasuku Honjo (l) and James Allison (r) (credit: The Daily Star)

This has always been the biggest difficulty in fighting cancer, because cancer cells are actually our own cells gone berserk the white blood cells in our immune system won’t fight them. For decades scientists have searched for some way to alert those white blood to attack the cancer cells.

Drs. Allison and Honjo worked by studying the chemical ‘checkpoints’ that white blood cells use to recognize ‘friendly’ cells. Dr. Allison succeeded in identifying one such checkpoint that he called CTLA-4 while the checkpoint Dr. Honjo discovered he named PD-1. Once these two checkpoints were understood it became possible to develop drugs that inhibited their function. Without the correct recognition signal the white blood cells now attacked the cancer cells.

This new technique is not without its problems. For one thing it is expensive, the chemical checkpoints differ for every person. For another the drug sometime simply fail to work and rarely they can even cause the patients immune system to begin attacking healthy cells. Nevertheless, checkpoint inhibitors as the drugs are known, have brought miraculous recoveries in patients whose cancer had been deemed untreatable by other techniques. The work of Drs. Allison and Honjo has brought us a powerful new weapon into our fight against cancer.

 

The three winners for the 2018 Nobel Prize in Physics are all pioneers in the use of Lasers in both biology and medicine. Doctor Arthur Askin of Bell Laboratories received his share of the prize for his development of lasers as ‘Optical Tweezers’. You see the particles of light do have momentum and a beam of light can direct ‘radiation pressure’ on an object it strikes. This allowed Dr. Askin to employ the intense light of lasers to actually to hold and even manipulate tiny objects such as individual cells and even down to single atoms.

2018 Nobel Prize winners in Physics, Donna Strickland (l), Gerard Mourou (c), and Arthur Askin (r) (Credit: The India Express)

The two other scientists sharing the physics prize are Doctor Donna Strickland of the University of Waterloo and Gerard Mourou for their work in high intensity, short pulse duration lasers. The work of Drs. Strickland and Mourou has had extensive applications in industry and medicine and is perhaps best known for it use in Lasik eye surgery.

This years physics Nobel also garnered some attention because Dr. Strickland became the first woman in fifty-five years to receive the award, and only the third woman ever. The only comment I’ll make on that aspect of the award is that I hope the day soon comes when the sex or ethnicity of a Nobel Prize winner is a matter of no importance whatsoever.

 

Finally we have the 2018 recipients of the Nobel Prize for Chemistry who are Francis H. Arnold of the California Institute of Technology along with George P. Smith of the University of Missouri and Sir Gregory P. Winter of the MRC Laboratory of Molecular Biology at Cambridge, UK. All of these scientists have worked in the field of organic chemistry with some of the most complex chemicals known to science.

Chemistry Nobel Laureates for 2018. Gregory P. Winter (l), Francis H. Arnold (c), and George P. Smith (Credit: NPR)

Doctor Arnold’s research has concentrated on “the directed evolution of enzymes” those organic catalysts that perform so many important functions in living creatures. Meanwhile Dr. Smith developed a technology known as ‘phage display’, using a virus that infects bacteria to develop new forms of proteins while Dr. Winter used phage display to direct the evolution of antibodies, thereby producing new pharmaceutical drugs. Many drugs are now being developed by this technique including some that neutralize toxins, combat rheumatoid arthritis, psoriasis and other autoimmune diseases.

The yearly choice of those scientists who receive the Nobel Prize is often the only time that the important work being carried out by scientists receives any publicity in the news media. Perhaps, given the acrimonious, contentious and partisan nature of so much of our news these days it might do us good if our nightly news programs spent a little more time on stories about the advances of science being made everyday. Stories like those about this year’s Nobel Prize recipients.

 

 

 

Better Thanksgiving through Chemistry

Some holidays are religious, some are patriotic but let’s be honest, Thanksgiving is all about the food. So tomorrow, as we wait impatiently for ma, or grandma, to perform that wonderful miracle in the kitchen maybe we should all take a moment to think about chemistry, that’s right chemistry.

Cooking is really just practical organic chemistry after all. Consider the changes your turkey will go through as the heat of your oven makes it so delicious. The muscle proteins will coagulate making them easier to digest, the carbohydrates in the skin will caramelize making it nice and crispy while the lipids will liquefy making everything wonderfully moist.

Heat is also important in preparing our vegetables, breaking down the tough cellulose cell walls. If you boil your potatoes don’t forget to salt the water, and not just for taste. Salt also raises the boiling temperature of water and is simply a good catalyst speeding up many chemical reaction.

Besides heating there are other important cooking techniques as well. Consider making a nice vinaigrette for your salad. Now we all know that oil and water don’t mix but if you employ mechanical agitation, shake them or stir with a whisk, you can produce thousands of little oil bubbles suspended in the vinegar. This is called an emulsion and here’s a little secret, add a teaspoon of mustard before you shake. The proteins in the mustard dissolve in the vinegar but can hook onto one of those oil drops helping to keep the emulsion from separating. The mustard also adds a lot of flavor.

Perhaps the most complex chemistry performed in the kitchen involves yeast. Yeast are living cells of a fungal organism and their metabolism is as complex as any creatures but we humans use then basically for two purposes. When added to a mixture of carbohydrates and lipids, flour and butter, the yeast will produce carbon dioxide bubbles making the bread dough rise. The other use is to produce alcohol from simple sugars giving us the nice glass of Riesling I plan on having with my turkey.

Yes, a delicious meal is really just better living through chemistry. Have a Happy Thanksgiving.