All posts by Kevin

Nanotechnology: A Source of Free Energy?

Recently, I have been researching on alternative energy sources as part of a Chemistry related science club presentation. Solar panels, hydroelectric dams, wind turbines, geothermal heat pumps, were the first ideas that popped into my mind. We commonly hear about these forms of technology that are used to harness the renewable energy sources that are available to us and significant research and development have vastly improved our efficiency in utilizing these sources. However, many of these options are of larger scales and as an individual consumer, we may not have the capability or accessibility to switch towards these renewable sources even if we wanted to. Researching further into smaller scale forms of renewable energy technology, I found that innovations of all sizes are taking place, the most interesting of which is in the nascent field of nanotechnology used in harnessing solar power.

A Ted Talks by Justin Hall-Tipping, founder of a nanotechnology based energy research company called Nanoholdings, discusses some of his latest creations on how to “generate, transmit, store, and use”(Nanoholdings) solar power. Initially, he began with a common problem of the transfer of heat energy through windows in a home. The picture below illustrates how in the summer, the energy coming from the sun is heating the home that we are trying to keep cool, while in the winter, the heat is escaping from the home we are trying to keep warm.

Screen shot 2011-11-09 at 11.22.52 PM

Aiming to give consumers the ability to control the heat transfer occurring through their windows, Nanoholdings’s nanotechnology material uses Carbon, which undergoes a reaction where “graphite is blasted by a vapor, and when the vaporized Carbon condenses, it condenses back into a different form…called a Carbon nanotube”(Hall-Tipping).

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Vaporizing Carbon                             Structure of Carbon Nanotube

The unique thing about this nanotube is that it is “a hundred thousand times smaller than the width of one of your hairs” and “a thousand times more conductive than Copper”(Hall-Tipping). Because Carbon at the nanoscale behaves and looks very differently, instead of being black and solid, it is actually transparent and flexible. Combined with a plastic during manufacturing, this Carbon nanotube can actually undergo permanent changes in color by using merely “two volts from a millisecond pulse” (Hall-Tipping) per color change. If this material were used on a window, in its colored state, it will reflect away all heat energy from the sun, helping to insulate a cool home. Vice versa, while in its transparent state, it will allow all heat energy from the sun to pass through, helping to warm a home.

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Transparent Carbon Nanotube            Colored Carbon Nanotube

Another ongoing project at Nanoholdings called “NIRVision”, uses nanotechnology like above to develop “flexible, thin films…to convert infrared light into visible light”(Nanoholdings). Similar to how more modern night-vision goggles work, a “photo-detector film converts invisible infrared light into electrons…these electrons stimulate an optical film like a thin flexible display, to create a visible image”(Nanoholdings). As we know, the flow of electrons is a source of electrical energy. Hall-Tipping goes on to describe how if we combined the film created in NIRVision with the Carbon nanotube illustrated above, then we would have a material that takes “infrared radiation and converts it into electrons” (Hall-Tipping) and because of its flexibility and transparency, we would be able to attach it to any surface to ultimately become a free source of clean energy.

The applications of this nanotechnology-developed material are endless, as a free source of clean energy is the solution to both our rising energy demand and our Earth’s rising temperature. Unfortunately, this material is still being tested and until we are able to efficiently manufacture it at a low cost to the environment, we must continue our gradual movement towards renewable sources of energy and a more environmentally conscious mindset. Similar to Steven’s post on the revolutionary perspective of silk, Nanoholdings was able to take one of the most common and abundant elements, Carbon, view it from a different perspective, and alter it in a way as to develop a material with new and desired properties. An even greater implication lies in how Hall-Tipping is able to combine two different technologies with different applications and generate a new one with completely new applications. Developing brand new technology may be life changing, but sometimes the most sublime of solutions can lie in how well we can take advantage of what we already have.

Works Cited

Hall-Tipping, Justin. “Justin Hall-Tipping: Freeing Energy from the Grid | Video on TED.com.” TED: Ideas worth Spreading. TED Conferences, Oct. 2011. Web. 09 Nov. 2011. <http://www.ted.com/talks/lang/eng/justin_hall_tipping_freeing_energy_from_the_grid.html>.

Nanoholdings. “Nanoholdings – Portfolio – New Technologies – Nirvision.” Nanoholdings. Nanoholdings LLC. Web. 09 Nov. 2011. <http://nanoholdings.com/portfolio/new-technologies/nirvision>.

Rechargeable Batteries

Energy is what powers our world, and humans’ never ending thirst for it has become a real problem for the Earth today. While researching for my Extended Essay, I wanted to further my research into the field of energy. One form of energy that deals with the flow of electric charge is electricity and is a form of energy that society cannot live without today. We can generate electricity from non-renewable sources like burning fossil fuels or renewable technologies like wind turbines, and even from smaller sources like a battery. Batteries simply put are cells that use stored chemical energy and through a chemical reaction, are able to create electrical energy that we can use. There are many forms of batteries and, like the Earth’s natural resources, can be either non-renewable or renewable sources. Likewise the non-renewable batteries are often wasteful and polluting when disposed of, while the renewable ones can be used for far longer periods of time and are greener as well. Of the many types of renewable batteries, the one that greatly interested me during my search for an EE research question was the lithium-ion rechargeable battery.

The lithium-ion battery is designed and works as most rechargeable batteries do. Within the cell of a lithium-ion battery, there are three main parts to its design: a positive electrode (anode), a negative electrode (cathode), and an electrolyte that is generally an organic solvent such as ether. As illustrated in the diagrams below, the anode and cathode are dissolved in the electrolyte, and are split by a separator that only allows for the flow of ions. The anode is often made from compounds such as lithium-cobalt oxide or lithium iron phosphate, while the cathode is often made from carbon such as the allotrope graphite. When a lithium-ion battery is being used or discharging its energy, the lithium ions on the anode will pass through the electrolyte and separator and flow to the cathode. Meanwhile, the electrons will not flow through the electrolyte and instead will flow through the external circuit. This flow of electrons is what thereby generates the electrical power used for appliances.

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Vice versa when a lithium-ion battery is recharged, the lithium ions will then pass back from the cathode, through the electrolyte and separator, and back to the anode. In turn, the electrons will then flow back through the external circuit and become stored for later use. This movement of ions and electrons in a rechargeable battery are related processes. If the ions were to completely discharge, then the electrons would stop flowing, and on the other hand, if the flow of electrons is stopped because there is an incomplete circuit, then the flow of ions will stop as well. However, as we have all seen in our daily appliances, batteries will still ultimately diminish in energy even if they are not used. This is because the flow of ions is still present, but is often very slow when there is an incomplete circuit.

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By understanding the process behind a rechargeable battery, I began to see just how much of an impact rechargeable batteries like the lithium-ion battery have on our lives today. The advantages of rechargeable batteries, namely the lithium-ion battery, are many. This includes having a far greater energy output than previous types of battery such as lead-acid batteries. In addition, they are very light and can be shaped in various sizes, making it very compatible with electronics today. However, these advantages are small in comparison to the fact that lithium-ion batteries do not suffer from the “memory effect”. Previous rechargeable batteries, like the nickel-cadmium battery, suffered from this effect in which if the battery were not fully discharged before it was recharged, then its maximum energy capacity would slowly decrease and ultimately ruin the battery. Lastly, maybe the greatest advantage of all is the fact that they are relatively less harmful to the environment if disposed of than other rechargeable batteries which often have poisonous metals and acids. Their long life cycles in turn allow for longer use before replacing them, which makes lithium-ion batteries a great substitute for other more expensive and environmentally harming batteries. Having all these advantages does not mean that there are not any disadvantages such as their greater cost of making and sensitivity to extreme temperatures. However as the world is slowing moving into a digital age where more and more of society is becoming electronic based, the lithium-ion battery will be a commonplace item of use in future electronics. They are slowly replacing older, less efficient, and more polluting batteries, and thus are a first step in helping to improve our high-energy consumption demands and making the earth a slightly greener place.

Works Cited

Brain, Marshall. “HowStuffWorks “How Lithium-ion Batteries WorkHowstuffworks “Electronics” HowStuffWorks, Inc. Web. 09 Mar. 2011.

Lithium Secondary – Rechargeable – Cells.Electropaedia, Energy Sources and Energy Storage, Battery and Energy Encyclopaedia and History of Technology. Web. 09 Mar. 2011.

Woodford, Chris. “How Lithium-ion Batteries Work: How Does a Rechargeable Battery Work? A Simple Introduction.Explain That Stuff! Science and Technology Made Simple. 29 July 2009. Web. 09 Mar. 2011.

Yano, Chris. “Memory Effect.Wikipedia, the Free Encyclopedia. 09 Mar. 2011. Web. 09 Mar. 2011.

Soap, An Overlooked Friend

What do you do before you eat and after you go to the bathroom? Well, if you’re sanitary, hopefully you’ll remember to wash your hands with soap and water each and every time, but does washing your hands with soap and water really cleanse them completely or is it merely a convention passed down for generations?

Soap1

It was an ordinary Tuesday as always. Wake up, eat breakfast, go to school, learn, participate in an after school activity, and then come back home to dinner and homework. As I looked back on my regular day of life, I wondered “What did I do the most today?” and aside from breathing and blinking, washing my hands was the one action I did more than anything else. Thinking back, since kindergarten and up until now, parents, teachers, and even friends always say, “wash your hands with soap and water before you do anything” and I have always thoughtlessly obeyed this idea. But only recently have I begun to question the usefulness of this action and whether soap really does its job as a cleansing agent.

Lets start with soap. Simply defined, soaps in general are all made up of mixtures of sodium or potassium salts of fatty acids. These salts can be made from numerous methods, but the most common is by reacting oils or fats (acids) with an alkali (e.g. sodium or potassium hydroxide) at 80°-100°C. This process is called saponification and is illustrated by the equation below.

fat + NaOH ––> glycerol + sodium salt of fatty acid

CH2-OOC-R-CH-OOC-R-CH2-OOC-R(fat) + 3NaOH(or KOH) –>

CH2-OH-CH-OH-CH2-OH(glycerol) + 3R-CO2-Na(soap)

*R = (CH2)14CH3

This is how soap is made, but how soap cleanses your hands when you wash with water is due to the soap molecules’ structure and solubility. The long hydrocarbon chain in soap is non-polar and hydrophobic, which means that it is repelled by water. The tail of the soap molecule is polar ionic and hydrophilic, which means that it is water soluble. These two opposite tails are what make soap an emulsifier and can be seen in the picture below.

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A Soap Molecule

An emulsifier is a substance that can disperse one liquid into another liquid, such as making oil (which attracts dirt) disperse into water. This property of an emulsifier is at work when oil is mixed with a soap and water solution, namely when you wash your hands. The soap molecules work as a bridge between the polar water molecules and non-polar oil molecules. The hydrophilic tail of the soap molecule interacts with water molecules through dipole-dipole interactions and hydrogen bonding. The hydrocarbon chains of the soap molecule does not interact with water molecules and instead cluster together due to Van der Waals forces and form structures called micelles. In these micelles, the tail of the soap forms a negatively-charged spherical surface with the hydrocarbon chains inside the sphere.

Soap2

A Soap Micelle

Micelles can trap oil and dirt in the center of the molecule. In addition, due to their negative charge, soap micelles repel each other and remain water soluble, which then allows them to be washed away. Thus the special characteristic of soap to clean, lies in its ability to attach itself to oil and dirt and then get washed away by water. Contrastingly, if you were to only wash your hands with water, the dirt and oil might still be washed away but it is far less likely than if you washed your hands with soap and water.

From my research into the chemistry behind soap’s cleansing abilities, I have also realized the implications and importance of emulsifiers in our daily lives. Emulsifiers, like soap, help to connect two naturally repellent substances so that we are able to utilize both their properties. For example, an emulsifier is often used in salad dressing so that the naturally repellent vinegar and oil can then easily mix together. As for soap, whether it be washing hands or showering, it helps rinse off the oil and dirt on our bodies far more effectively than just water. Due to its properties as an emulsifier, humans are able to rely on soap as a first wall of defense against the spread of diseases. Likewise it is a hallmark to maintaining cleanliness in a society. We might not realize it in our fast paced lives, but soap truly has a worldly impact and we must not let this convention of washing our hands just “slip” away.

Bibliography

“Emulsion.” Wikipedia, the Free Encyclopedia. 26 Nov. 2010. Web. 01 Dec. 2010. <http://en.wikipedia.org/wiki/Emulsion>.

Helmenstine, Anne M. “How Soap Cleans – How Does Soap Clean?” Chemistry – Periodic Table, Chemistry Projects, and Chemistry Homework Help. About.com. Web. 01 Dec. 2010. <http://chemistry.about.com/od/cleanerchemistry/a/how-soap-cleans.htm>.

“How Does Soap Work?” Edinformatics — Education for the Information Age. Web. 01 Dec. 2010. <http://www.edinformatics.com/interactive_molecules/soap.htm>.

“Micelle.” Wikipedia, the Free Encyclopedia. 30 Nov. 2010. Web. 01 Dec. 2010. <http://en.wikipedia.org/wiki/Micelle>.

Shandilya, Anju. “How Does Soap Work.” Buzzle Web Portal: Intelligent Life on the Web. Web. 01 Dec. 2010. <http://www.buzzle.com/articles/how-does-soap-work.html>.