You know rubber,huh? Squeezable, leaping rubber!

Everyone knows rubber. We all start to use it in the childhood when we write down a mistake. ''Write with pencil and then erase it easily with a rubber!'' Is a sentence commonly adressed to small children in lower grades.

      However, rubber is used worldwide in many parts of our lives and not only in school desks.

      It is usually incorrectly thought of rubber as just school rubber.
Due to its flexibility and durability, rubber is a widely used material in various fields. It is an essential item in the fields of car manufacturing, arts and crafts, technology and even in sports.
      However, we can also connect this term  to latex - a raw ''rubber'' material used in its own or further processed form.

   Generally, rubber is an elastomer, a material with great ability to deform and after the deforming power is gone, it returns to its former shape. Latex is more of a fluid, milk-like fluid and it is emulsion of polymers microparticles in aqueous solution.

    It is basically present in every plant and it covers many types of molecules - varying from proteins, carbohydrates and oils to alkaloids and resins.

In industry, we can use two types of latex. We have either natural latex or synthetic latex.
The natural one is by letting the fluid pour out the from gumtree whereas synthetic latex is produced through polymerization of butadiens, usually isopren (2-methylbuta-1,3-dien) or copolymerization of butadien with styren.

                                                                      isopren

                                                                                

       Furthermore, natural rubber is the most important product obtained from latex; more than 12,000 plant species yield latex containing rubber, though in the vast majority of those species the rubber is not suitable for commercial use.This latex is used to make many other products as well, including mattresses, gloves, swim caps, condoms, catheters and balloons.

Latex from the chicle and jelutong trees is used in chewing gum.

In the case of synthetics, rubber is made from latex through interesting process called vulcanization of rubber. It is comprised of adding sulphur to the polymer latex molecules. Sulphur has an interesting characteristics - it can create so-called di-sulphoric bridges (crosslinks) while creating tenuous 3D site and therefore improving some qualities like tensile strength or elasticity (the ability to return from the deformation)

 We know for example rubber balls made thanks to this process...

 or 30% mass of added sulphur is called ebonite, a very hard and electric-insulating material used in great variety of products varying from bowling balls to saxophone mouthpieces. It replaced expensive ebony wood in the end of 19th century.

Then, we can think of latex like dried latex from the opium poppy, which is opium, the source of many useful opiates and other alkaloids of high value. (morfin - anesthetics, but also heroin - very dangerous drug)

heroine:

 When you see someone doing something similar to the last picture, you can be sure he/she is in a very very bad situation :-(

Finally, we can think of latex of course in clothing! Worn on the body (or applied directly by painting) it tends to be skin-tight, producing a "second skin" effect. :-)

For now, you should have a little bit better idea, when we say ''gum'' or rubber''

But be aware, especially in the case of clothing - do not put a latex head or whatever over your mouth and nose, ''rubber'' materials can be of different quality, but be sure with one thing - one cannot breath through it :-)

Sources:
http://www.solarnavigator.net/rubber.htm
http://en.wikipedia.org/wiki/Latex
http://cs.wikipedia.org/wiki/Kau%C4%8Duk
http://xantina.hyperlink.cz/organika/uhlovodiky/areny.html
http://www.jergym.hiedu.cz/~canovm/polymery/polymera/pbdstk.htm
http://en.wikipedia.org/wiki/Vulcanization
http://www.viewzone.com/chewinggum.html
http://singlets.co.cc/late-19th-centuary-clothing.html
http://bowlingtipsandtechniques.com/your-options-on-finding-a-great-bowling-ball/

How to force your paper mill to produce electricity?

I'm sorry for the gap in adding new articles, but things to do had cumulated rapidly here and I had have to study for my final exams, which took part in the half of May...

But recently, I have found that scientists discovered an interesting and new method how to transform thermal energy into electricity! The new method is called lead telluride thermo-electrical device.

    Although it is not a new idea at all and many researches had done these devices before, they had never overcome a magical 10% line of efficiency whereas material scientists at the university of Illinois created a 14% one!
     That means that dirty factories could recycle 14% of their overall waste heat! And it was calculated that it IS definitely worth of it. Simply imagine that we could use waste energy, which is, without doubt, present in many industrial fields - varying from glass and steel production to coal plants and paper mills!

Moreover, we could reduce amounts of carbon dioxide released in the atmosphere as well as green house effect in consequence.

Before describing the new method to you, can you even imagine how does a thermo-electrical device work?
Well, I think it's not so obvious, so let's start with it.

 From wikipedia, there is a nice definition, so I'll quote it from there:

''The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice-versa. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely, when a voltage is applied to it, it creates a temperature difference. At the atomic scale, an applied temperature gradient causes charged carriers in the material to diffuse from the hot side to the cold side, similar to a classical gas that expands when heated; hence inducing a thermal current.''

Moreover, we can measure quite precise temperature with these devices.

    On the other hand, there is a problem of electron-scattering, which means that electrons are deflected from their original trajectories and the efficiency of such machines is lowered.

It is due to several facts:
- In thermoelectronic devices, there is also a certain magnetic field created and thanks to the ''theory of quantum electrodynamics'' it influences electrons' trajectories (or we can refer to Lorentz force)
- Secondly, electrons hold charges and due to their electrostatic Coloumb forces they repulse each other

Nevertheless, the breakthrough in using these devices will be probably caused by the new method!

Let's describe it:

In general, you put nanocrystals of rock salt into lead telluride (lead an tellurium on a lattice).

On one hand, lead telluride has been part of past experiments with thermoelectric devices and NU researchers were not the first to attempt a nanoscale inclusion in bulk material in order to improve the thermoelectric properties of a material, but they did their job better than others. Their new material reduces the phenomenon called “electron scattering,” (I tried to describe above) an enemy of thermoelectric conversion efficiency.

Hope it was understandable :-)

So we can use our waste energy far more efficiently now, but will our politicians give financial incentives for electricity produced by these devices with high price for purchase?

But definitely, I must admit that new opportunities with nanomaterials are vast and I am looking forward to future inventions :-)

sources:
http://www.greenoptimistic.com/2011/01/22/lead-telluride-thermoelectric-record/
http://cleantechnica.com/2011/01/20/14-nanomaterial-breakthrough-in-waste-heat-electricity-could-turn-dirty-industries-in-us-into-electric-power-generators/
http://www.nature.com/nchem/journal/v3/n2/full/nchem.955.html
http://www.instructables.com/community/Help-Thermo-Elecetric-Generator/
http://en.wikipedia.org/wiki/File:Peltierelement_16x16.jpg
http://www.webelements.com/compounds/lead/lead_telluride.html