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Grafeno Semiconductor

• Graphene

• Graphene oxide (GO)

• Few-layer graphene (FLG) or multi-layer graphene (MLG)

• Reduced graphene oxide (rGO)

• Graphite nanoplatelets; graphite nanosheets; graphite nanoflakes

Graphene oxide (GO)From Graphite Oxide to Graphene Oxide

While graphite is a 3 dimensional carbon based material

made up of millions of layers of graphene, graphite oxide

is a little different. By the oxidation of graphite using

strong oxidizing agents, oxygenated functionalities are

introduced in the graphite structure which not only expand

the layer separation, but also makes the material

hydrophilic (meaning that they can be dispersed in water).

This property enables the graphite oxide to be exfoliated

in water using sonication, ultimately producing single or

few layer graphene, known as graphene oxide (GO). The

main difference between graphite oxide and graphene

oxide is, thus, the number of layers. While graphite oxide

is a multilayer system in a graphene oxide dispersion a

few layers flakes and monolayer flakes can be found.

Fullereno

Hasta el siglo XX, el grafito y el diamante eran las únicas

formas alotrópicas conocidas del carbono. En

experimentos de espectroscopia molecular, se observaron

picos que correspondían a moléculas con una masa

molecular exacta de 60, 70 ó más átomos de

carbono. Harold Kroto, de la Universidad de Sussex,

James Heath, Sean O'Brien, Robert Curl y Richard

Smalley, de la Universidad de Rice, descubrieron el C60 y

otros fullerenos en 1985, en un experimento que consistió

en hacer incidir un rayo láser sobre un trozo de grafito.

Ellos esperaban efectivamente descubrir nuevos

alótropos del carbono, pero suponían que serían

moléculas largas, en lugar de las formas esféricas y

cilíndricas que encontraron. A Kroto, Curl y a Smalley se les concedió el premio Nobel de Química en 1996,

nanotubos•1952 Primera imagen de nanotubos de carbono, por L. V.

Radushkevich y V. M. Lukyanovich.10

•1991 Descubrimiento oficial por Iijima (MWCNT).11

•1993 Descubrimiento del primer nanotubo monocapa

(SWCNT).12

•1991-2000 Producto de interés principalmente

académico.

•2000-2005 Se investiga su uso industrial.

Síntesis del Grafeno

Mechanical exfoliation of grapheneMechanical exfoliation is the original method used by Sir Andre Geim and Sir

Kostya Novoselov to isolate a single graphene flake. Scotch tape was used to

remove layers from bulk graphite, these layers are then transferred to a

substrate such as silicon. On removing the tape single layer graphene with large crystal sizes is left on the substrate.

CVDCreating graphene using the CVD process

One of the most popular methods to create graphene at this moment in time is by using a process

called chemical vapour deposition (CVD). The benefits of using CVD to deposit materials onto a

substrate are that the quality of the resulting materials is usually very high.

Graphite Oxide

Aplicaciones

MEMBRANES

Imagine clean drinking water for millions in developing countries. The

development of graphene-based membranes at The University of Manchester brings that possibility closer.

Graphene-based composite materialsLightest, strongest, safest, greenest

A graphene-based composite aircraft wing could drastically decrease weight,

reduce the detrimental effects of lightning strike damage and increase fuel

efficiency and range. This could result in the world's lightest, strongest, safest,

greenest plane.

Graphene in EnergyImagine fully charging a smartphone in seconds, or an electric car in minutes. That's the power of graphene

Graphene supercapacitors could provide massive amounts of power while using

much less energy than conventional devices. Because they are light, they could

also reduce the weight of cars or planes.

Storing wind and solar power

At The University of Manchester we're also investigating graphene's potential in

grid applications and storing wind or solar power with our growing number

of commercial partners.

Medical scienceDrug delivery

The lateral dimensions of these two dimensional (2D) materials can be adjusted

between nanometres and millimetres, and their thickness can be tuned from

single to hundreds of monolayers and their flexural rigidity can also be modulated.

The flat surface can be easily functionalized enabling modification of the surface

property (from hydrophobicity to hydrophilicity) and this is unprecedented among

other nanomaterials, offering enormous design capabilities as a platform for drug

delivery and ultrasensitive biosensors.

Cancer treatment

Graphene sensorsGraphene is an ideal material for sensors. Every atom in graphene is exposed to its environment allowing it to sense changes in its surroundings. For chemical sensors the goal is to be able to detect just one molecule of a potentially dangerous substance. Graphene now allows for the creation of micrometre-size sensors capable of detecting individual events on a molecular level.

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