Featured Element: Ethanol

By: Maria Janine L. Juachon

Sometimes, having more of something isn’t always the best choice.

Ethanol, also commonly known as ethyl alcohol, is a compound with a structural formula of CH3CH2OH, often written as C2H5OH, C2H6O. Commonly abbreviated as EtOH, it is an essential part of our daily lives seeing as it is used in antiseptics, in post-mercury thermometers, and in alcoholic beverages. In addition to this, it is also commonly used in microbiology laboratories as a prerequisite before any experiments can be conducted; however, it is to be noted that specifically 70% ethanol is the best concentration to be used – not 50% and not 100%. This article will attempt to explain the reason for the said case.

As stated, ethanol is used to kill microorganisms. It works by denaturing their proteins and dissolving their lipids of their cellular membrane. The water in the ethanol solution is the portion that actually does the denaturing. Using higher concentration makes the ethanol less effective because there cells cannot be denatured by the water; meanwhile, lower concentrations do not allow the ethanol to be as effective because it cannot break down the all lipids or allow the water to get into the cells.

To explain further, using higher concentration, say 100%, of alcohol will only most likely lead to coagulation of protein. If pure alcohol is poured over the bacterial cell, the alcohol will go through the cell wall of the bacteria in all directions, coagulating the protein just inside the cell wall; this coagulated protein would then stop the alcohol from penetrating farther from the cell, and no more coagulation would take place. This would result to the cell would getting sealed and become merely inactive and not dead. (Under favourable conditions the cell may revert to its active state).

Seventy percent is considered the optimum concentration because it was found that it coagulates protein at a relatively slower rate. This allows penetration all the way through the cell before coagulation can block it. Then the entire cell is coagulated and the organism dies.

 

References:

http://futurescienceleaders.org/researchers2012/2012/11/why-70-ethanol/

http://www.protocol-online.org/biology-forums-2/posts/18178.html

http://molecularbiology.forums.biotechniques.com/viewtopic.php?f=5&t=32134

https://www.researchgate.net/post/Why_is_70_ethanol_used_for_wiping_microbiological_working_areas

http://dgmanila.com/2013/12/hygienix/ (Picture)

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Recent News in the Scientific Community!

By: Charles Jerome R. Bartolo

SHAPESHIFTING GOLD

The production of most materials wastes potentially useful resources. A method to produce materials atom per atom is only used for laser materials, used in telecommunications, because of its rather high production costs and size limitations. Researchers led by Chad Mirkin at the Northwestern Univerisity in Evanston, Illinois have devised a way to manipulate gold nanoparticles into different crystalline structure to possibly highly particular and complex shapes and sizes, only by utilizing DNA.

Read the full article: http://www.sciencemag.org/news/2016/02/dna-makes-lifeless-materials-shapeshift?utm_campaign=email-news-latest&et_rid=17056517&et_cid=256735

Source: Science Magazine

 

IMPROVED SOLAR CELLS BOAST EFFICIENCY

Cadmium telluride (CdTe) solar cells have been modified to produce a higher voltage output than its previous model, increasing its voltage near that of the GaAs solar cells, the current highest-voltage record holder.

Read the full article: http://www.nature.com/articles/nenergy201621

Source: Nature Magazine

 

SCALING THE PEAK

Transition states are momentary chemical species produced by your reactants before they turn into products. Scientists are unable to determine the energy of these short-lived species due to their instability and short life span. However, a team of scientists led by Joshua Baraban at the Massachusetts Institute of Technology.

Read the full article: http://www.scientificamerican.com/article/for-the-first-time-chemists-measure-the-energy-of-a-chemical-reaction-s-transition-state/

Source: Scientific American

How Stuff Works: Red Hot Chili Peppers!

By: Carlos Bryan M. Tecson

You may have experienced the burning sensation when eating a hot spicy food before, may it be from Korean noodles, Mexican food, and many other more, for this week’s How Stuff Works, I will be discussing about Chili Peppers. Surely, almost everyone have tasted this little guys before, burning everyone’s tongues and refusing to be wash downed with water. Anyways, I will be talking about what compounds are inside these guys that make your tongues burn.

Chili peppers are composed of many compounds, but the thing that makes them painfully hot is the compound called capsaicin. Capsaicin is vanilloid, a compound containing a functional group called vanillyl group, which is an irritant for mammals, including humans, that produces that painful burning sensation when ingesting a chili pepper. Capsaicinoids, capsaicin itself and other compounds produced by chili peppers, binds to a receptor in the mucous membrane of the mouth when ingested; the receptor is actually linked with heat. So when the Capsaicinoids bind to your mouth, it produces the burning sensation. If Capsaicinoids are repeatedly ingested, it actually depletes the receptor. Meaning, you can actually build up tolerance. The painful burning sensation produces endorphins, a compound that acts as natural painkillers of the body. Capsaicin is actually a toxic compound but chili peppers don’t have high enough capsaicin content to be harmful. Capsaicin is not only found in chili, it is also used in pepper spray, and of course, in low concentrations as its inflammatory effects can cause the eyes to close.

The heat of chilies are measured in many ways, one is the Scoville scale. Scoville scale is a taste test in which a measured extract from peppers are diluted with a solution of water and sugar.

There is a common myth in removing the painful sensation produced by chilies. Many people believes that drinking water will remove it, however that’s not true. Capsaicin molecule is actually hydrophobic, making it not soluble in water, however it is readily soluble in alcohol and oil. Alcohol in beer still can’t remove the hotness because it is too low in concentration. The most practical thing you can do to remove the hotness is to drink milk. Milk has a protein called casein, which is lipophilic, can be dissolved in fats, oils, lipids, etc., and it can remove the Capsaicin molecules.

Capsaicin may burn your tongues but studies say that it can prevent cancer.  Capsaicin prevents growth and destroys prostate cancer cells without harming the other cells. Capsaicin binds to the membranes of the cancer cells, and then they pull it apart – destroying it. So, some good can be seen from these little guys.

Chili peppers have been an important thing in our world today, used in many culinary dishes, defined the culture of many places, used in many commercial products like pepper spray and many more. With the some technical terms discussed, I hope that you learned something new about how chili works.

References:

http://www.compoundchem.com/2014/01/15/why-chilli-peppers-are-spicy-the-chemistry-of-a-chilli/

https://munchies.vice.com/en/articles/chili-peppers-could-be-the-secret-to-killing-cancer

http://nutritiondiaries.com/2012/04/21/featured-food-red-chili-peppers (picture)

Featured Compound: Chemistry of Water

The Death Chemical
By Olyn Desabelle

DHMO starts with D – and so does death.

Dihydrogen monoxide (DHMO) is a colorless and odorless substance. It is a widely used chemical compound that even goes by many names such as Dihydrogen Oxide, Hydrogen Hydroxide, Hydronium Hydroxide, and Hydric acid.

DHMO can cause DNA mutations, make proteins lose functionality, disrupt cell membranes, and alter neurotransmitters. The chemical components of DHMO can be found in extremely strong acids and bases such as Fluoroantimonic Acid and Lithium Diisopropylamide; in highly explosive substances such as Acetone Peroxide and Methyl Nitrate, and in the most common case, it can be found in the top contributor to diabetes – Glucose. The Hydrogen in DHMO even has an explosive after it – the Hydrogen Bomb.

Research suggests that the deadly DHMO has directly caused thousands of deaths, which include, but are not limited to:

  • Death due to accidental inhalation of DHMO
  • Severe tissue damage after prolonged exposure to solid DHMO
  • Serious burns caused by gaseous DHMO
  • Short circuits caused by DHMO contamination of electrical systems
  • Pre-cancerous tumors and lesions containing DHMO

Despite these side effects, DHMO is still used in several industries worldwide:

  • As additives to food products, including baby food, soups, and canned beverages
  • In liquid pharmaceuticals such as cough medicines
  • In bathroom products such as shampoo, shaving creams, and lotions
  • In common drinks such as coffee, beer, and juice
  • In swimming pools

The harmful DHMO is abundant on Earth and has been a major component in natural disasters such as floods and tsunamis. As of 2016, 100 percent of people who died have ingested DHMO at least once in their life.

What should we do about this?

According to U.S. researchers Patrick K. McCluskey and Matthew Kulick, roughly 90 percent of the people they have interviewed were willing to sign a petition to ban DHMO in the United States. In order to be safe from it, we must spread our knowledge about it so that we can stand a chance against DHMO – the death chemical.

Sources:

https://www.dhmo.org

http://weknowyourdreamz.com/water.html (Picture)

 

Featured Element: The Chemistry of Hydrogen

By: Carlos Bryan M. Tecson
The first element in the periodic table, being the lightest element of all, is the element Hydrogen. For sure, you have already heard of it. Hydrogen is the most abundant element in the universe, from the things found here in Earth like water, acids, plants, sugars, up to the heavenly bodies like the sun, stars, comets and the like. Hydrogen, as I’ve said earlier, is the lightest element; it has an atomic weight of 1 AMU. This little element has been found in almost everything; over ninety percent of all the atoms in Earth contain hydrogen. Let’s find out how!

Before anything else, let’s talk about Hydrogen’s history. Hydrogen was first discovered by Henry Cavendish in 1766. Hydrogen was believed to be many different things, people had no idea what is it. Antoine Lavoiser, another chemist, is the one who named it Hydrogen. Its name comes from the Greek meaning of “water producer” (“hydro” means water and ”gennao” means “to make”).

Now for the nerdy but exciting part, Hydrogen’s properties! Hydrogen exhibit a lot of properties, too many that I can’t mention all of them here, but these properties, I’m about to tell you, are the notable ones. Hydrogen is a nonmetal and is placed on the first group and first period. Hydrogen has a s1 electron configuration, like your alkali metals. However, it varies from alkali metals as it forms cations (H+) more reluctantly compared to other alkali metals. Hydrogen is also a nonmetal and it forms hydride anions (H). It can also make dihydrogen (H2) like your halogens. However, hydrogen differs from halogens with its electron affinity; it has a lower electron affinity that halogens.

Because of its unique properties, it has many uses. Hydrogen has been used for hydrogenation of vegetable oils, this process involves the use of hydrogen to convert vegetable oils to margarine. Hydrogen is also used in rocket fuels. Hydrogen is also a good reducing agent; it is used to produce metals like iron, copper, nickel from their ores. Also, there are many extensive researches done on the viability of hydrogen being a source of energy.

With these properties and uses, surely we can say that Hydrogen is one of the most important elements in the world. A lot of properties and uses for a single atom huh? Who knows, there might be still hidden facts about this little atom. Now you know something about Hydrogen, be sure to read more and you might be the one to discover on of the hidden things about hydrogen and might be the next big thing in the scientific community.

 

References

http://chemwiki.ucdavis.edu/Core/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Block/1_s-Block_Elements/Group__1%3A_The_Alkali_Metals/Chemistry_of_Hydrogen

http://www.chem4kids.com/files/elements/001_speak.html

How it Works: Cement!

By Justine Nicole Dator

Cement is a major part of the industrial world. It is the binder of concrete, and concrete makes up the structure of many buildings. Without concrete, many infrastructure would not be around today, or would be made using other materials like wood, steel, and the like.

Exactly how does cement work? In this article, we’ll focus on one of the most common types of cement – Portland cement. Cement is made first by quarrying and crushing different materials and combining them in exact proportions. These materials include calcium oxide (CaO), silica (SiO2), alumina (Al2O3), and iron oxide (Fe2O3). The resulting combination is put in a cylindrical kiln which heats up the mixture. The kiln is on an incline, and the raw materials enter through the higher end, and slowly move the length of the kiln as it rotates. At the end of the kiln, fuel is used to heat up the materials, causing them to react.

As it moves down the cylinder, the mixture changes. First any excess water is lost by evaporation. Due to the loss of water and carbon dioxide, decomposition happens. The process is called calcination. Calcination is subjecting a substance to heat without the intent of fusing the mixture together, but with the intent of causing a chemical change, such as decomposition of compounds. Next is clinkering, where calcium silicates form. The final stage is the cooling stage.

The resulting compound is called a clinker. The clinker contains certain compounds which affect the overall properties of cement. Mixing these compounds in different proportions can make different kinds of cement.

COMPOUND PROPERTY IT AFFECTS
Tricalcium aluminate Frees plenty of heat during hydration;
Tricalcium silicate Hardens quickly; responsible for early cement strength gain
Dicalcium silicate Hardens slowly; responsible for later strength gain of cement
Ferrite Reduces melting temperature of raw materials; does not contribute to strength

 

Once water is mixed, the cement forms a paste with the aggregates available to make the concrete. The water caused the hardening of the concrete through hydration. In hydration, the compounds in cement form chemical bonds with the molecules of water to become hydrates. The water is very important because the ratio of water to cement is what determines how strong the concrete is.

The expound more on how cement works when mixed with water. We’ll discuss the interaction of water with tricalcium silicate. Once pure water is added (the water must be pure in order to avoid any unnecessary reactions from occurring), the tricalcium silicate reacts to release calcium ions, hydroxide ions, and heat. Once the system becomes saturated, the calcium hydroxide begins to crystalized, while calcium silicate hydrates form. From this, more calcium silicate hydrate forms, and the crystals grow thicker, making it harder for water to reach the tricalcium silicate. Finally, the calcium silicate hydrate hardens and the cement paste is now solid.

The other components of the cement interact in the same way with water. Their reactions may be a bit more complicated since they involve the compound gypsum. Nevertheless, hydration is a very important process that is undergone by cement. With all the complicated terminology over, I hope that you have properly understood how cement binds with aggregate to create concrete – which is a vital material in the modern-day world.

 

References:

[1] http://matse1.matse.illinois.edu/concrete/prin.html

[2] http://www.engr.psu.edu/ce/courses/ce584/concrete/library/construction/curing/Composition%20of%20cement.htm

[3] http://www.lafargeholcim.com/cement-solutions (Picture)

She suffered, Yet she conquered

A Marie Curie Science Feature

By: David Nathaniel N. Niro

Nothing in life is to be feared; it is only to be understood.” This was imparted by the scientist of our interest today, who was credited for pioneering researches on radioactivity and on the discovery of the elements Radium and Polonium.

Maria Salomea Skłodowska Curie, better known as Marie Curie, was a Polish physicist and chemist. She was born on Warsaw, Poland in the year 1867.

Lack of money prevented her from formal higher education, but even so she found ways to learn something new each day. Having an unquenchable thirst for knowledge, Marie Curie is not someone who gives up just yet.

When an opportunity arose, she readily grasped the chance to be enrolled in a university and moved to France in 1891. Young as she was, she read and studied books to her heart’s desire. Upon entering Sorbonne University in Paris, she discovered her love for learning physics and mathematics.

It was in 1894 when she met Pierre Curie, her partner in science and in life. They first became research colleagues at the School of Chemistry and Physics in Paris. There, they pioneered work in invisible rays brought about by uranium, as recently discovered by Becquerel.

One of her notable innovations is the fact that the mineral pitchblende, which contains uranium ore, was more radioactive than pure uranium in itself. The substance’s radioactivity seemed to be so strong that she doubted if it was really the uranium alone which was causing such phenomenon. She looked for this “thing”, then later she realized she just discovered a new radioactive element. The powder that they extracted, later called Polonium, was 330 times more radioactive than uranium. However, the liquid that remained was still observed as very radioactive even after extracting polonium, so she and her husband believed that another radioactive element is present in this mineral – Radium. Despite financial problems (Pitchblende is significantly expensive), Marie Curie pushed through to seek knowledge accompanied by hazards that were yet to be realized during that time. Working with 20kg of mineral batches provided harsh radioactive environment, and in addition to that, their negligence and ignorance to the risks of radioactive materials eventually caused them to be ill. Her hardwork has paid off in 1902, when finally Marie Curie was able to isolate radium in the form of radium chloride from pitchblende.

Because of this, she had won a Nobel Prize in 1903. However, life seems to be unfair, for 3 years after, Marie’s life was struck with tragedy as her husband, Pierre, was killed in a street accident. Curie, strong and indomitable as she was, continued her life and further pursued her interests.

Countless contributions were also noted to her like her involvement in mobile X-ray units during WWI as the director of the Red Cross Radiological Service, and later as the head of the laboratory where she works in. It was reinforced with the numerous awards given to her by the scientific community.

During the course of her life, she empowered women for Marie Curie was the first of the many. She was the first woman to win a Noble Prize, and she did so twice in multiple science fields. She was also the first woman to be a professor at the University of Paris. Until her untimely death, she was the first woman to be entombed on her own merits, recognizing her steadfast spirit as a scientist and as a person.

In that way, she suffered, yet she conquered.

 

References:

http://www.mcg-neuss.de/tradition/das-leben-von-marie-curie-1867-1934 (Picture)

https://www.mariecurie.org.uk/who/our-history/marie-curie-the-scientist

http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/marie-curie-bio.html