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Teen creates bio-plastic from banana peels

Sixteen-year-old Elif Bilgin of Turkey has developed a way to replace traditional petroleum-based plastic with banana peels.

The Turkish teen took home a US$50,000 prize for her project “Go Bananas!” Thursday after winning the second annual Scientific American Science in Action Award, associated with Google Science Fair.

“My project makes it possible to use banana peels, a waste material which is thrown away almost every day, in the electrical insulation of cables,” Bilgin said in a media statement.

“This is both an extremely nature-friendly and cheap process, which has the potential to decrease the amount of pollution created due to the use of plastics, which contain petroleum derivatives.”

Bilgin spent two years developing the bio-plastic, which does not decay. She said the process is so easy that it is possible to repeat at home, with special care taken for chemicals used in the production process.

In September, the teen will compete at Google’s California headquarters for the overall Google Science Fair prize for 15-to-16 year olds. She will also have access to a one-year mentorship.

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SUBMISSION: Yeast culture

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Breaking Bad nails.

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Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1,[1] significantly larger than for any other material. These cylindrical carbonmolecules have unusual properties, which are valuable for nanotechnology, electronics, optics and other fields of materials science and technology. In particular, owing to their extraordinary thermal conductivity and mechanical and electricalproperties, carbon nanotubes find applications as additives to various structural materials. For instance, nanotubes form only a tiny portion of the material(s) in (primarily carbon fiber) baseball bats, golf clubs, or car parts.[2]

Nanotubes are members of the fullerene structural family, which also includes the spherical buckyballs, and the ends of a nanotube may be capped with a hemisphere of the buckyball structure. Their name is derived from their long, hollow structure with the walls formed by one-atom-thick sheets of carbon, called graphene. These sheets are rolled at specific and discrete (“chiral”) angles, and the combination of the rolling angle and radius decides the nanotube properties; for example, whether the individual nanotube shell is a metal or semiconductor. Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). Individual nanotubes naturally align themselves into “ropes” held together by van der Waals forces, more specifically, pi-stacking.

Applied quantum chemistry, specifically, orbital hybridization best describes chemical bonding in nanotubes. The chemical bonding of nanotubes is composed entirely of sp2 bonds, similar to those of graphite. These bonds, which are stronger than the sp3 bonds found in alkanes and diamond, provide nanotubes with their unique strength.

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Vanadium oxidation states

Distinctive colors reveal the oxidation states of vanadium (V) in certain aqueous solutions: V+2 (violet), V+3 (green), V+4 (blue) and V+5 (yellow) 

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Cross-Section Tissue of Marram Grass Leaf

… reveals cellular happy smiling faces …

via ‏@MrPrudence

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spot the mistake? :P

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Hello!

Hello to my followers. Just so you know, I'll be doing more revision posts next year (probably) but over summer I'll probably send links and write posts to do with general interesting sciencey stuff :) 

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Average Bond Enthalpies

This is the average enthalpy change required to break 1 mole of a given type of bond by homolytic fission in the molecules of a gaseous species. What does this mean?! The energy required to break 1 mole of the bond given, ie O-H, in all the gaseous molecules of a chemical. The "Average" part comes in when you have polyatomic molecules such as CH4. The energy required to break each of the C-H bonds differs, so you find an average.  

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Halogenoalkanes

These are created through radical substitution (see the post on that for more). The general formula for halogenoalkanes with one halogen is : "C(n)H(2n+1)X" where X shows a halogen such as Br or Cl There are Primary, Secondary and Tertiary halogenoalkanes, depending on the number of R groups or hydrogen atoms the adjoining carbon is attached to (like alcohols) The C-X bond has a dipole. The X is d-  and the carbon is d+.  This leaves it open to "attack" by negative nucleophiles, such as aqueous OH- ions. X- is a stable ion on its own, so X is substituted easily. This is known as nucleophilic subtitution.  Because the C-F bond is the strongest (highest bond enthalpy), and the C-I bond is the weakest, fluoroalkanes are the least reactive and iodoalkanes are the most reactive. 

image from http://www.chemhume.co.uk

Halogenoalkanes also react with water, in a hydrolysis reaction, to make alcohol.  C2H5Br + H20 ---> C2H5OH + HBr.   

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The radical substitution of an alkane with chlorine

1) Inititation - first, the radicals have to be made. * represents a radical. Cl2 (+UV radiation) ---> 2Cl*    this is homolytic fission   2) Propagation - this is where the radical substitution takes place.  CH4 + Cl* ---> CH3* + HCl CH3* + Cl2 ---> CH3Cl + Cl* Remember for two step propagations like this, or the decomposition of ozone, the catalyst has to come out the other side for the reactions to keep happening. If it doesn't...you've gone wrong :P 3) Termination - this is how the reaction stops: the radicals are "mopped up" Cl* + Cl* ---> Cl2   (ie you turn off UV and it stops breaking down) CH3* + CH3* ----> C2H6  (ethane)  CH3* + Cl* ---> CH3Cl (chloromethane)  As you can see, ethane is produced, as well as some other chemicals like CH2Cl2. This kind of radical substitution is difficult to control.  

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Did you know, ozone means "to smell" because it has a distinct, sharp smell, like chlorine?!

Ozone is found in the stratosphere. It protects us from harmful UV rays. How ever, low level ozone is harmful and can damage the respiratory system.  Ozone in our atmosphere is constantly breaking down and reforming. O3 (+UV radiation) ---> O* + O2 O* + O2 ---> O3  If left undisturbed, there would always be a protective layer, as these two reactions are in dynamic equilibrium. HOWEVER human beings release chemicals which catalyse the reaction of O3 + O* ---> 2O2, meaning the ozone layer is being depleted. (see the post on ozone depletion for more info)  

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Collision theory

Particles must collide in order to react.  For a successful reaction, they must have enough energy to overcome the activation energy (the minimal amount of energy needed for a reaction to occur). Also, they must be in the correct orientation. The bigger the concentration, the more particles there are in a given volume, which increases the chance of a successful collision. An increase in temperature also increases reaction rate, because the particles are moving quicker, so there will be more frequent collisions above the activation energy. *analogy*. For people to start a relationship, they have to meet each other. If you had "heat" (all dressed up, probably drunk) then they might "react" - but they need to be the correct sexual orientation (duh!) for this to happen. The more people there are in a club, the more chance there is of someone getting lucky :P