Applications of fullerenes – Everything you want to know about the current applications of one amazing substance
Are the applications of fullerenes really so wide, interesting, unique and useful?
There is a description of relatively new carbon molecule in this article, its actual application in various branches and potential.
This molecule evince special properties that can influence industry, scientific research, give new possibilities to treating serious diseases, etc.
Maybe you will make a decision to buy C60 after having read the article and use some of its great application.
Before giving an answer, let us try to get to know themselves a little bit more.
Fullerene is an allotrope of carbon. Individual carbon atoms create hollow sphere, ellipsoid, tube or other shapes that consist of hexagons and pentagons.
Based on the molecular shape, they can be divided into next groups:
- Spherical - named buckminsterfullerenes or buckyballs (association with football)
- Cylindrical - hollow tubes of very small dimension with single or multiple walls (nanotubes or buckytubes). Predominantly used in electronic industry.
- Mega tubes - Varying in dimensions than nanotubes as larger in diameter with walls of different thickness.
- Polymers – 2D or 3D, formed under high pressure and temperature conditions
- Nano „onions – Spherical particles having multiple layers which surrounds buckyball core. They are used for example as lubricants or for energy saving.
- Linked “ball-and-chain” dimmers – Two buckyballs linked by a carbon chains
Application of fullerenes hit many industrial and scientific branches
They are used for example in these branches:
- Industry – cosmetic, energy saving, electronic, pharmaceutic
- Science – chemistry, physics, biology
Short description of allotropes
As it was said, fullerenes are allotropes of carbon. The word allotropy is created from two ancient Greek words allos (meaning other) and tropos (“manner” or “form”). Allotropy is the property of some (chemical) element to exist in two or more different forms, in the same physical state. Those substances are known as allotropes of this element.
Individual allotropes (of an element) are different modification of an element that means the atoms of the element are bonded together in a different manner.
Allotropy or allotropism (from Ancient Greek allos (meaning 'other'), and tropos (meaning 'manner, form') is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of these elements.
Very simple and generally known example can be graphite and diamond. Both are allotropes of carbon, but carbon atoms in diamond are bonded together in tetrahedral lattice arrangement, whereas atoms of graphite are in sheets of a hexagonal lattice).
Examples of the best known allotropes
Some examples of the best-known allotropes are given below with a short description.
- Carbone: for example graphite (soft), diamond(hard), fullerenes (stable can be harder than diamond)
- Oxygen: for example dioxygen (O2, colorless), ozone (O3-blue), tetra oxygen (O4-metastable), octaoxygen (red)
- Phosphorus: for example white phosphorus (crystalline solid of tetra phosphorus (P4) molecules, black phosphorus (semiconductor, analogous to graphite)
Discovery and research milestones
History of their discovery is relatively new and very interesting. The milestones are given in the next points with their short description.
- 1966 - David Edward Hugh Jones (a British chemist and author, under the pen name Daedalus). He published for 38 years in New Scientist, Nature and other from 1964 until 2002. Daedalus most noteworthy scientific idea was probably the prediction of hollow carbon molecules before buckminsterfullerene was known, and long before a Nobel Prize was awarded for the discovery. His hypothesis was not accepted.
- 1970 - Eji Osawa (June 6, 1935, from 1990 full professor at Toyahashi University of Technology, where he retired in 2001), Japanese chemist. He predicted the existence of C60 in 1970. Eji Osawa noticed that the structure of a corannulene molecule was a subset of a football shape, and he came with a hypothesis that a full ball shape could also exist. Japanese scientific journals reported his idea, but only in Japan.
- 1970 - R.W.Henson, with no prior knowledge of Daedalus nor Osawa proposed the structure and made a model of C60. However, evidence for this new form of C was very weak and was not accepted. His work was never published. The international journal Carbon mentioned his contribution in a special issue only in 1992 (Carbon, Vol 30 No 8).
- 1984 - Exxon company scientists noticed an interesting phenomenon during the evaporation of graphite with a laser and cooling in supersonic jet: bigger carbon clusters contained more molecules with even number of atoms then odd. They did not detect prevailing occurrence of clusters with 60 carbon atoms and therefore they did not come to know what substance they observed.
- 1985 - Discovery of C60, the most prominent fullerene.
Harold Kroto (at that time University of Sussex), Richard Smalley and Robert Curl (at that time Rice University in Houston) explored composition of stars atmosphere and of interstellar dust. They observed an exotic molecule during the laboratory tests. The molecule was a cluster of 60 carbon atoms. The first pure fullerit (fullerites are the solid phases of C60) was produced in Heidelberg (Max Planck Institute for Nuclear Physics).
- 1990 - W. Krätschmer (Max Planck Institute for Nuclear Physics in Heidelberg) together with his PhD student Konstantinos Fostiropoulos and with Donald Huffman (the University of Arizona) found a method that allows production of C60 in sufficient quantities.
- 1991 - Discovery of superconductivity of C60 with alkali metals in Bell Laboratories
- 1992- First preparation of AC60. These phases exhibit a polymer structure, which is air-stable.
- 1992- TDAE C60-Fullerene is supposed to be an itinerant ferromagnet.
- 1996- The Royal Swedish Academy of Sciences awards the Nobel Prize in chemistry to R. F. Curl, H. W. Kroto and R. E. Smalley for the discovery of fullerenes.
What special properties lead to application of buckminsterfullerenes
They evince special properties, for example:
- superconductivity at 35K,
- hardness higher then diamond,
- extraordinary resistance to physical Influences (temperature and pressure),
- special electric properties,
- some organic derivatives of fullerenes evince magnetic properties,
- wide non-linear optic reaction,
- possibility to insert into the hollow,
- catalytic properties,
- antioxidant properties
- antibacterial properties
If we look at the list above, we must confirm this new interesting substance must be very useful in many fields of human activities. Its special properties known up to now determine them to the group of very important items for industry, business or science. Their development and research is permanently going on, which brings new possibilities of their application and next research projects.
Actual buckyballs application with some short description
From 1985 to 1990, a series of studies indicated that C60 and C70 were indeed exceptionally stable and provided convincing evidence for the cage structure proposal. In addition, evidence was obtained for the existence of other smaller metastable species, such as C28, C36, and C50, and experimental evidence was provided for “endohedral” complexes, in which an atom was trapped inside the cage. Experiments showed that the size of an encapsulated atom determined the size of the smallest surrounding possible cage. In 1990 physicists Donald R. Huffman of the United States and Wolfgang Krätschmer of Germany announced a simple technique for producing macroscopic quantities of C60, using an electric art between two graphite rods in a helium atmosphere to vaporize carbon. The resulting condensed vapors, when dissolved in organic solvents, yielded crystals of C60. Because they could be received in sufficient amounts, research on this amazing matter could expand to a remarkable degree and the new field of chemistry was born.
Medicine and biological Application
- Antioxidant and neuroprotective activity
- Antiviral activity
- Anticancer treatment, conjugation with proteins and DNA
- Drug delivery and gene delivery
- Photodynamic therapy
- Diagnostic application
- Antimicrobial activity
- Carrier for drug delivery
- Genetic engineering
- Artificial implants
- Diagnostic tool- Due to their ability of fluorescence with specific biomolecules
Application in chemistry, physics, geology and industry
- Solar cells
- In protective eye wear
- Hydrogen gas storage (energy storage)
- Hardening agents
- Cosmetic industry
- Superconductivity in the range 19 to 40 K
- Chemistry – endohedral species
Application in medicine - for medical therapeutics and medical diagnostic
One of the most important use is medicine.
A wide spectrum of applications brings significant benefit. The research is not finished and has great potential to the future.
- Fullerenes are active molecules that can be used as an antioxidant because it can easily react with radicals due to the high affinity of the electron.
- They can make excellent antioxidants. This property can be attributed to the large number of conjugated double bonds they possess and a very high electron affinity of these molecules (due to low energy of the unoccupied molecular orbital).
- They can react with a number of radicals before being consumed. A single C60 molecule can interact with up to 34 methyl radicals before being used up. That is why, these molecules are also known as the 'world's most efficient radical scavengers' or 'radical sponge'. Perhaps, one of the major advantages of using these molecules as an antioxidant is that these can be localized within the cell.
- These molecules also act as effective cytoprotectors against the ultraviolet A irradiation. These bind to the Reactive Oxygen Species (ROS) and prevent damage to cells. A water-soluble derivative C60 with polyvinylpyrrolidone or Radical Sponge is usually added to cosmetics. This prevents skin damage and premature aging of the skin without any side effects. Immediate absorption by the intact skin is the most important advantage of this molecule.
- molecules also prevent lipid peroxidation by scavenging peroxy radicals, and thus, prevent cell cytotoxicity related with them.
- Fullerenes are used as antiviral agents. Its unique molecular structure, antioxidant effect and biological compatibility provides this use.
- Ability to suppress the replication of the HIV virus
Their potential as antiviral agents brought about quite a bit of attention. The most exciting aspect of this may be their ability to suppress the replication of the human immunodeficiency virus (HIV), and thus, delay the onset of acquired immunodeficiency syndrome (AIDS). Dendrofullerene 1 and Derivative 2, transisomer have been seen to inhibit the HIV protease, and thus, prevent replication of HIV 1. Bivalent metal derivatives of amino acid derivatives of fullerene, like C60-1-Ala, are also seen to be active against HIV and human cytomegalovirus replication. These molecules are usually inserted in the hydrophobic domains of proteins (binding site of protease in HIV).
- The reverse transcriptase in HIV, inhibition of hepatitis C virus (HCV)
Another target for their amino acid derivative is the reverse transcriptase in HIV. It is found that these molecules are more active than the non-nucleoside analog inhibitors usually used. Its cationic derivatives are antibacterial and antiproliferative in nature and most of them can inhibit HCV.
- Its water insoluble derivatives show antiviral activities against enveloped viruses, when vesicular stomatitis virus is incubated with fullerene derivatives under visible light, it loses its infectivity. This can be attributed to the generation of singlet oxygen.
- Some fullerenes can form conjugates with proteins and DNA. This situation can help to develop anti-cancer treatments.
- Drug delivery and gene delivery can use fullerene molecules. A chemotherapeutic agent covers their surface. This agent finds the cancer cell and then it is transported directly there.
- Drug delivery is the proper transportation of a pharmaceutical compound to its site of action, whereas gene delivery is the introduction of foreign DNA into cells to bring about a desired effect. It is therefore of utmost importance to deliver these molecules with safety and great efficacy. Fullerenes are a class of inorganic carriers, these molecules are preferred as they show good biocompatibility, greater selectivity, retain the biological activity, and are small enough to be diffused. DNA sequences are attached to the amino acid derivatives of fullerene. These sequences detach from their carrier with the loss or denaturation of the amino groups. Biochemical studies have shown greater protective abilities of these derivatives as compared to the traditional vector used.
- They can be used in the delivery of hydrophobic drugs. In fact, these carriers are used in the slow release of these hydrophobic drugs in the system. A significant anticancer activity has been observed for C60 -paclitaxel conjugate. An additional benefit is that they can easily diffuse through intact skin―a fullerene-based peptide has demonstrated the ability to penetrate via skin.
- Photosensitizers in Photodynamic Therapy
- Photodynamic Therapy (PDT) is a form of therapy of using non-toxic light sensitive compound which, when exposed to light, becomes toxic. PDT can target altered and malignant cells. Fullerenes are usually used as these compounds, they get excited upon irradiation, when these molecules return to ground state; they give off energy that splits the oxygen present to generate singlet oxygen, which can be cytotoxic in nature.
- In the presence of electron donors, they are converted to C60-radicals (excellent acceptors of electrons). These radical anions transfer electrons to oxygen molecules and convert them to anionic superoxide and hydroxyl radicals. These radicals damage the DNA and may bring about cell death. Sometimes, certain fullerenes form conjugates with proteins and DNA; this has a potential application in developing certain anticancer therapy as well.
- The highly water-soluble C60-N vinylpyrrolidone copolymer is used as an agent for photodynamic therapy.
- Possibility to use them for osteoporosis treatment because of its preferential localization
With new chemical entities, the practice of medicine now has the option of molecular therapies requiring next-generation diagnostics and therapeutics. Nanotechnology is used for the creation of useful, functional materials, devices and systems through controlling and manipulating matter at the molecular level.
Fullerenes are exceptional free radical scavengers, or antioxidants. They can intercept free radicals and neutralize them before they cause cellular harm for many diseases, for example:
- Arthritis – interruption of MC (Mast cells) associated diseases.
- Asthma- prevention of MC activation in the lung, so an asthma attack does not occur.
- Allergy - Mast cells (MC) are found in most tissues throughout the body. They have traditionally been associated with initiating and propagating the allergic response. Fullerene derivatives may be capable of blocking this process and, unlike current medications, prevent the allergy reaction before it has a chance to proceed.
Development of the nanomedical fields is in their infancy, especially in the area of carbon-based nanomaterials. The studies exploring the toxicity of fullerenes on human systems are not still finished and are the topic of much debate.
A polymer-based organic photovoltaic cell can solve request to find an economical and lightweight medium for the conversion of solar energy. The principle of these solar cells work is transfer of electrons from a material that gets excited when irradiated with light (the material is the donor). An acceptor molecule takes this electron (in excited state). The molecule is transferred further to the electrode. Fullerenes make excellent acceptors, because they have high electron affinity and ability to transfer electrons. These organic photovoltaic cells are complexes of fullerenes and polymers (bulk heterojunctions).
A common acceptor used in organic solar cells is Phenyl-C61-butyric acid methyl ester (PCBM). It is usually used in conjunction with the polymer polythiophene (P3HT) as an electron donor.
In Protective Eye wear
Fullerenes have optical limiting properties. This refers to its ability to decrease the transmittance of light incident to it. These molecules can therefore be used as an optical limiter that can be used in protective eye-wear and sensors. This optical limiter will only allow the light below a particular threshold to pass through as well as maintain the light being transmitted at a constant level, much below the intensity that may cause damage to the eye or the sensor.
Hydrogen Gas Storage (6.7 m3 of H2 / 1 kg of C60)
Fullerene one-of-a-kind molecular structure make possible to hydrogenate and dehydrogenate quite easily. The carbon rings of this substance are conjugated with C=C double bonds. On hydrogenation, these bonds can be broken easily giving rise to C-C single bonds and C-H bonds. When these hydrides are heated up, the C-H bonds break easily to give back fullerene.
Why? Because the bond strength of C-H is lower as compared to that of C-C.
If we consider 36 hydrogen atoms are held up to with one fullerene molecule, then one kg of it can hold up in normal condition about 6.7 m3 (237.5 ft3) of hydrogen. If means that a classic matchbox in the Czech republic (5.0x3.5x1.5 cm3 or 1.97x1.38x0.59 inch3) full of C60 can hold about 291.2 liter (10.3 cubic feet) of gas hydrogen.
The color of hydrogenate C60 changes in dependence of hydrogen content. The black color changes to brown, red, orange, and finally, to yellow with increasing of H2 content.
These molecules store hydrogen in a better, safer, and more efficient way than devices currently being used.
Fullerenes can represent the future of developing relatively lightweight metals with greater tensile strength, without serious change of the metal ductility, probably because of the small size and high reactivity due to the sp2 hybridization of the carbon. This allows dispersion strengthening metal matrix by their interaction with metals. Its admixture to the lightweight Ti-24.5AI-17N alloy caused a 30% increase in the hardness of the alloy.
- Substitution for a diamond films necessary in various electronic devices. Because fullerenes are quite similar in structure to diamonds, there is a possibility of their conversion to diamonds with minor rearrangement of the carbon atoms. The conversions have been recently demonstrated. Converted fullerenes can be used in various electronic devices.
At present, studies are in progress to examine their potential use in sensors as well in development of molecular conductors. The greatest practical application of these molecules might be in the cosmetic industries at this time
- Fullerenes in cosmetic sector play the important role of an anti-aging agents and anti-damage agents.
Application in chemical engineering, chemistry and physics
The C60 molecule goes through a wide range of unheard of chemical reactions. Next points show some of them.
- Accepting and donation of electrons: Ready to accept and donate electrons – it results to possible applications in batteries and advanced electronic devices.
- Addition of hydrogen or halogen atoms: The molecule readily adds atoms of hydrogen and of the halogen elements. Other groups, such as phenyl (a ring-shaped hydrocarbon derived from benzene, formula C6H5,) can replace the halogen atoms, and open useful routes to a wide spectrum of novel derivatives. Some of these derivatives show advanced materials behavior.
- Superconductivity in the range 19 to 40 K: Especially important are crystalline compounds of C60 with alkali metals and alkaline earth metals. These compounds are the only molecular systems whose superconductivity is at temperatures above 19 K. Observed superconductivity is in the range 19 to 40 K (−254 to −233 °C / −425 to −387 °F).
- Endohedral species: Particularly interesting in chemistry are so-called endohedral species, in which a metal atom (generically designated M) is physically trapped inside a fullerene cage. The resulting compounds (with the formulas M@C60) have been extensively explored. Vaporizing graphite disks or rods impregnated with the selected metal may trap atoms of alkali metals, alkaline earth metals and early lanthanides.
- Helium trapping into fullerene molecule and use in geology or in meteorites exploration:
- Heating C60 in helium vapor under pressure can also be trap helium atoms.
- Minute samples of He@C60 with unusual isotope ratios have been found at some geologic sites.
- Some samples also found in meteorites may yield information on the origin of the bodies in which they were found.
Future potential applications – what are ideas and possibilities of next development?
2 actual disadvantages against 2 advantages
- Still expensive – if you will make a decision to buy C60 you will have to calculate a little
- Their production is very time-consuming,
- Great potential to the future
- They are supposed to use in a lot of branches
Drugs against growing old treatment of Alzheimer’s or Parkinson’s disease
One of their basic property is a capability of multiple additional reactions. Therefore, there is an idea, that their ability to catch all the free radicals could result to drugs against growing old.
Free radicals are associated with human disease, including cancer, atherosclerosis, Alzheimer's disease, Parkinson's disease and many others. They also may have a link to aging, which has been defined as a gradual accumulation of free-radical damage
Inhibitors of AIDS protease – HIV/AIDS treatment
Protease inhibitors (PIs) are a class of antiviral drugs that are widely used to treat HIV/AIDS and hepatitis C. Protease inhibitors prevent viral replication by selectively binding to viral proteases (e.g. HIV-one protease) and blocking proteolytic cleavage of protein precursors that are necessary for the production of infectious viral particles.
Excellent solid lubricants
The discovery of C60 has led to a paradigm shift in the understanding of graphite, in particular graphene sheets on a small scale. It is now known that the most stable form of a carbon aggregate, containing tens to several thousands of atoms, is a closed buckyball or nanotube. This new understanding is not restricted to pure carbon but also applies to other sheet-forming materials such as boron nitride, which can also form nanotubes. Closed structures, incorporating sulfides of such metals as tungsten and molybdenum, exhibit excellent solid-lubricant properties.
Extensive use in electronics and optics
Fullerenes are supposed to use extensively in solar panels, electromagnetic radiation protection
Conducting carbon nanotubes may be coated with sheaths of metal sulfides to produce tiny insulated electrical wire.
Civil engineering, building constructions, constructing aircrafts and cars
Fullerenes and nanotubes have engendered much excitement, especially with regard to possible future applications, but so far, such applications have been rare. Nanotubes in particular may well bring about a revolution in materials science. For example, if SWNTs (single-walled nanotubes) can be made in bundles of 100 billion, then a material will be produced that may approach the limits of tensile strength possible for any known material involving the chemical bond. In practice, no material approaches its theoretical “intrinsic strength,” because of breakdowns brought on by the propagation of microscopic defects through the material. A bundle of nanotubes, however, may bypass this problem, as microscopic defects may anneal along the length of a particular tube and certainly should not propagate across the bundle—thus avoiding the problems that occur in conventional materials.
Estimates of potential tensile strength vary, but it is predicted that a 1-metre rod may reach 50 to 100 times the strength of steel at one-sixth the weight. The impact of such a material on civil engineering, building construction, aircraft, and automobiles would be spectacular.
In order to realize this potential, however, new processes will have to be discovered that can produce long (more than one meter), perfectly ordered bundles in which all 100 billion nanotubes preferably have the same diameter and atomic arrangement. No technology to achieve this exist at present; indeed, it is not even obvious what strategy might be used to reach this goal.
More realistically, carbon-nanotube composite materials exhibiting improved behavior over standard carbon-fibre composites are likely in the near term. In addition, applications on a small scale should be feasible for medical purposes—for instance, the strength of individual nanotubes may prove useful in microsurgery or nanosurgery.
This article is focused to the very interesting topic – to application of fullerenes, mainly buckminsterfullerenes. A short history of their discovery and research in the beginning of the article can help you understand the start and next quick development.
Maybe the summary of properties, applications and potential of these interesting substances has made you think over it more. On the other hand, you may meet some their interesting application personally.
Do you think that the new substance can seriously influence future industry, science, medicine?
Do you think this substance is important and that deserves our attention?