Fullerenes by pranav subash https://padlet.com/pranavmnmh/yrxw3m0jdkrk63rn en-us 2021-07-23 11:43:46 UTC 2021-07-27 04:10:32 UTC hello@padlet.com https://padlet-uploads.storage.googleapis.com/1276201055/6456ca184cffc9bfc324dcaeb2421106/graphene_.png ______________________________________________________________________ pranavmnmh https://padlet.com/pranavmnmh/yrxw3m0jdkrk63rn/wish/1661040009 Graphene, explained
What is it?
Graphene's a 2D crystal, the first one we ever discovered. It's the strongest, lightest, thinnest, most conductive material we know - and it's also in your pencil. It's transparent, malleable, and just about can take the form of any shape you can think of.  It's even stronger  300 times stronger than steel. If perfect wonder-material was a thing, graphene would be it. Its often called the next plastic.

Structure
Continuing on with its perfectness, graphene's amazingly simple to visualize and understand. It's a honeycombed (hexagonal) structure of carbon atoms, one atom thick, that looks like chicken wire. (Yep, one atom. It's purely 2 dimensional.)
In graphene, each carbon atom must be connected to three other.


Making Graphene
Buy a block of graphite, get a roll of scotch tape, tape it to the block and pull away. Repeat this till the layer stuck gets thinner and thinner - you now own probably the world's most important material.
(Making industrial graphene of higher quality in higher quantity is a bit more complicated, so we don't have to get into that in AS levels)


Uses and Applications
-  Graphene is the world's strongest material and can be used to enhance the strength of other materials. Dozens of researchers have demonstrated that adding even a trace amount of graphene to plastics, metals or other materials can make these materials much stronger - or lighter (as you can use a smaller amount of material to achieve the same strength). Eg - aerospace, building materials, mobile devices,
- Heat dissipation films and power grid's cables (conducting prowess)
- Microelectronics (for example to make LED lighting more efficient and longer-lasting)
- Extremely high surface-area to volume ratio makes it a very promising material for use in batteries and supercapacitors.
- additional applications: anti-corrosion coatings and paints, efficient and precise sensors, faster and efficient electronics, flexible displays, efficient solar panels, drug delivery, and more.




What's the catch?
There's 2 actually. Firstly, it's easy enough to produce graphene at a small scale, but since its just an atom thick, making it at a large scale with sufficient quality is complex and expensive. Once that's done and the graphene's in use, research shows that when graphene is subjected to strain equal in all directions, it morphs into a new structure that is mechanically unstable. The honeycomb arrangement of carbon atoms is driven toward isolated hexagonal rings, a new crystal that is structurally weaker.











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Sources:
https://www.youtube.com/watch?v=TBchoDY1vBc
https://www.graphene-info.com/graphene-applications
Engineers discover graphene's weakness - Phys.org
https://phys.org › news › 2010-12-graphene-weakness


Graphene by University of Manchester
]]> 2021-07-26 12:24:42 UTC https://padlet.com/pranavmnmh/yrxw3m0jdkrk63rn/wish/1661040009 Buckminsterfullerene joegeorgemathew https://padlet.com/pranavmnmh/yrxw3m0jdkrk63rn/wish/1661066076 What is it?
Buckminsterfullerene is a type of fullerene with the formula C60. It has a cage-like fused-ring structure.  Each carbon atom has three bonds. i
The shape of a Buckminsterfullerene is similar to that of a football. It has 20 hexagons and 12 pentagons.
The van der Waals diameter of a buckminsterfullerene molecule is about 1.1 nanometers (nm). The nucleus to nucleus diameter of a buckminsterfullerene molecule is about 0.71 nm.

Properties
-The C60 molecule is extremely stable, being able to withstand high temperatures and pressures.
-They do not bond to one another. They do however, stick together via Van der Waals forces.
-They are electrical insulators as the free electrons are held together by Van der Waals forces.
-They have low sublimation point, due to the weak intermolecular forces. They sublime at 600o C.

Uses
-Superconductors
-Lubricants
- Catalysts due to their high reactivity.
- Drug delivery systems, pharmaceuticals and targeted cancer therapies (in the future, probably)
-Based on the chemical properties like very high electron affinity and the large number of conjugated double bonds, fullerenes are known to act as excellent antioxidants. They are called "radical sponge” due to their ability to interact with a number of free radicals before being consumed. The major advantage of using them as an antioxidant is that they seem to be really safe and biocompatible that they can act within the cell.
-Fullerenes and their derivatives are believed to act as these compounds also termed as antiviral agents. One of their most exciting properties is the capability to suppress the HIV replication.




]]> 2021-07-26 12:56:48 UTC https://padlet.com/pranavmnmh/yrxw3m0jdkrk63rn/wish/1661066076 ______________________________________________________________________Nanotubes KR2005 https://padlet.com/pranavmnmh/yrxw3m0jdkrk63rn/wish/1661069271 What is it?
Nanotubes are a type of fullerene that  are cylindrical molecules that consist of rolled-up sheets of single-layer carbon atoms (graphene). They can be single-walled with a diameter of less than 1 nanometer or multi-walled , consisting of several concentrically interlinked nanotubes, with diameters reaching more than 100 nm. Their length can be made relatively long, reaching several micrometers or even millimeters, which can create high aspect ratios that are greater than 1000.

Properties
Electrical properties:
  • A single-walled nanotube also known as SWCNT(Single-walled carbon nanotubes) can behave like a metal and be electrically conducting; display the properties of a semiconductor; or be non-conducting depending on its structure. 
  • Multi-walled nanotubes also known as MWCNT(Multi-walled carbon nanotubes) are always conducting and achieve at least the same level of conductivity as metals. 
Carbon nanotubes also have unique thermal and mechanical properties like:
  • Their mechanical tensile strength can be 400 times that of steel
  • They are very light-weight, their density is one sixth of that of steel
  • Their thermal conductivity is better than that of diamond
  • Just like graphite, they are highly chemically stable and resist virtually any chemical impact unless they are simultaneously exposed to high temperatures and oxygen which makes them extremely resistant to corrosion.

Uses
A nanotube's hollow interior can be filled with various nanomaterials, separating and shielding them from the surrounding environment which is extremely useful for nanomedicine applications like drug delivery.

The intrinsic properties of carbon nanotubes make them the preferred material for use as electrodes in capacitors and batteries. carbon nanotubes possess good electrical conductivity, an extremely high surface area and their linear geometry makes their surface very accessible to the electrolyte.

Carbon nanotubes are also used in Air and Water Filtration, as apart from blocking the tiniest particles, can also destroy most bacteria.
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Sources
https://www.nanowerk.com/nanotechnology/introduction/introduction_to_nanotechnology_22.php
https://www.azonano.com/article.aspx?ArticleID=4842
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Video
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