Titanium dioxide 1

Titanium dioxide

Titanium dioxide

Identifiers

CAS number 13463-67-7 [1] 

PubChem 26042 [2]

ChemSpider 24256 [3] 

UNII 15FIX9V2JP [4] 

KEGG C13409 [5] 

ChEBI CHEBI:32234 [6] 

ChEMBL CHEMBL1201136 [7] 

RTECS number XR2775000

Jmol-3D images Image 1 [8]

Properties

Molecular formula TiO2

Molar mass 79.866 g/mol

Appearance White solid

Odor odorless

Density 4.23 g/cm3

Melting point 1843 °C

Boiling point 2972 °C

Solubility in water insoluble

Refractive index (nD) 2.488 (anatase)2.583 (brookite)2.609 (rutile)

Titanium dioxide 2

Thermochemistry

Std enthalpy offormation ΔfH

o298

−945 kJ·mol−1[]

Standard molarentropy So

298

50 J·mol−1·K−1[]

Hazards

MSDS ICSC 0338 [9]

EU classification Not listed

NFPA 704

Flash point Non-flammable

Related compounds

Other cations Zirconium dioxideHafnium dioxide

Related titanium oxides Titanium(II) oxideTitanium(III) oxideTitanium(III,IV) oxide

Related compounds Titanic acid

  (verify) [10] (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Infobox references

Titanium dioxide, also known as titanium(IV) oxide or titania, is the naturally occurring oxide of titanium,chemical formula TiO2. When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it is sourced fromilmenite, rutile and anatase. It has a wide range of applications, from paint to sunscreen to food colouring. Whenused as a food colouring, it has E number E171.

OccurrenceTitanium dioxide occurs in nature as well-known minerals rutile, anatase and brookite, and additionally as two highpressure forms, a monoclinic baddeleyite-like form and an orthorhombic α-PbO2-like form, both found recently atthe Ries crater in Bavaria.[11][12] It is mainly sourced from ilmenite ore. This is the most wide spread form oftitanium dioxide-bearing ore around the world. Rutile is the next most abundant and contains around 98% titaniumdioxide in the ore. The metastable anatase and brookite phases convert to rutile upon heating.[]

Titanium dioxide has eight modifications – in addition to rutile, anatase, and brookite three metastable phases can beproduced synthetically (monoclinic, tetragonal and orthorombic), and five high pressure forms (α-PbO2-like,baddeleyite-like, cotunnite-like, orthorhombic OI, and cubic phases):

Titanium dioxide 3

Form Crystal system Synthesis

rutile tetragonal

anatase tetragonal

brookite orthorhombic

TiO2(B)[13] monoclinic Hydrolysis of K2Ti4O9 followed by heating

TiO2(H), hollandite-like form[14] tetragonal Oxidation of the related potassium titanate bronze, K0.25TiO2

TiO2(R), ramsdellite-like form[15] orthorhombic Oxidation of the related lithium titanate bronze Li0.5TiO2

TiO2(II)-(α-PbO2-like form)[16] orthorhombic

baddeleyite-like form, (7 coordinated Ti)[17] monoclinic

TiO2 -OI[18] orthorhombic

cubic form[19] cubic P > 40 GPa, T > 1600 °C

TiO2 -OII, cotunnite(PbCl2)-like[] orthorhombic P > 40 GPa, T > 700 °C

The cotunnite-type phase was claimed by L. Dubrovinsky and co-authors to be the hardest known oxide with theVickers hardness of 38 GPa and the bulk modulus of 431 GPa (i.e. close to diamond's value of 446 GPa) atatmospheric pressure.[] However, later studies came to different conclusions with much lower values for both thehardness (7–20 GPa, which makes it softer than common oxides like corundum Al2O3 and rutile TiO2)[20] and bulkmodulus (~300 GPa).[21][22]

The oxides are commercially important ores of titanium. The metal can also be mined from other minerals such asilmenite or leucoxene ores, or one of the purest forms, rutile beach sand. Star sapphires and rubies get their asterismfrom rutile impurities present in them.[]

Titanium dioxide (B) is found as a mineral in magmatic rocks and hydrothermal veins, as well as weathering rims onperovskite. TiO2 also forms lamellae in other minerals.[23]

Spectral lines from titanium oxide are prominent in class M stars, which are cool enough to allow molecules of thischemical to form.

ProductionThe production method depends on the feedstock. The most common method for the production of titanium dioxideutilizes ilmenite. Ilmenite is mixed with sulfuric acid. This reacts to remove the iron oxide group in the ilmenite. Theby-product iron(II) sulfate is crystallized and filtered-off to yield only the titanium salt in the digestion solution. Thisproduct is called synthetic rutile. This is further processed in a similar way to rutile to give the titanium dioxideproduct. Synthetic rutile and titanium slags are made especially for titanium dioxide production.[] The use of ilminiteore usually only produces pigment grade titanium dioxide. Another method for the production of synthetic rutilefrom ilminite utilizes the Becher Process.Rutile is the second most abundant mineral sand. Rutile found in primary rock cannot be extracted hence the deposits containing rutile sand can be mined meaning a reduced availability to the high concentration ore. Crude titanium dioxide (in the form of rutile or synthetic rutile) is purified via converting to titanium tetrachloride in the chloride process. In this process, the crude ore (containing at least 70% TiO2) is reduced with carbon, oxidized with chlorine to give titanium tetrachloride; i.e., carbothermal chlorination. This titanium tetrachloride is distilled, and re-oxidized in a pure oxygen flame or plasma at 1500–2000 K to give pure titanium dioxide while also regenerating chlorine.[24]

Aluminium chloride is often added to the process as a rutile promotor; the product is mostly anatase in its absence.

Titanium dioxide 4

The preferred raw material for the chloride process is natural rutile because of its high titanium dioxide content.[]

One method for the production of titanium dioxide with relevance to nanotechnology is solvothermal Synthesis oftitanium dioxide.

Titanium oxide nanotubes, SEM image.

Nanotubes

Anatase can be converted by hydrothermal synthesis to delaminatedanatase inorganic nanotubes[25] and titanate nanoribbons which are ofpotential interest as catalytic supports and photocatalysts. In thesynthesis, anatase is mixed with 10 M sodium hydroxide and heated at130 °C for 72 hours. The reaction product is washed with dilutehydrochloric acid and heated at 400 °C for another 15 hours. The yieldof nanotubes is quantitative and the tubes have an outer diameter of 10to 20 nm and an inner diameter of 5 to 8 nm and have a length of 1 μm.A higher reaction temperature (170 °C) and less reaction volume givesthe corresponding nanowires.[26]

Another process for synthesizing TiO2 is through anodization in an electrolytic solution. When anodized in a 0.5 weight percent HF solution for 20minutes, well-aligned titanium oxide nanotube arrays can be fabricated an average tube diameter of 60 nm andlength of 250 nm. Based on X-ray Diffraction, nanotubes grown through anodization are amorphous.[27]

ApplicationsThe most important application areas are paints and varnishes as well as paper and plastics: They process about 80%of the world's titanium dioxide consumption. Other pigment applications like printing inks, fibers, rubber, cosmeticproducts and foodstuffs account for another 8%. The rest is used in other applications, for instance the production oftechnical pure titanium, glass and glass ceramics, electrical ceramics, catalysts, electric conductors and chemicalintermediates.[28]

PigmentTitanium dioxide is the most widely used white pigment because of its brightness and very high refractive index, in which it is surpassed only by a few other materials. Approximately 4.6 million tons of pigmentary TiO2 are consumed annually worldwide, and this number is expected to increase as consumption continues to rise.[] When deposited as a thin film, its refractive index and colour make it an excellent reflective optical coating for dielectric mirrors and some gemstones like "mystic fire topaz". TiO2 is also an effective opacifier in powder form, where it is employed as a pigment to provide whiteness and opacity to products such as paints, coatings, plastics, papers, inks, foods, medicines (i.e. pills and tablets) as well as most toothpastes. In paint, it is often referred to offhandedly as "the perfect white", "the whitest white", or other similar terms. Opacity is improved by optimal sizing of the titanium dioxide particles. Some grades of titanium based pigments as used in sparkly paints, plastics, finishes and pearlescent cosmetics are man made pigments whose particles have two or more layers of various oxides -amongst which we have often titanium dioxide, iron oxide or alumina – , in order to have glittering, iridescent and or pearlescent effects similar to a certain extent to crushed mica alone or guanine based products, but in addition to these effects a limited color change is possible in certain formulations depending on how and at which angle the finished product is illuminated and the thickness of the oxide layer in the pigment particle : one or more colours appear by reflection while the other tones appear due to interference of the transparent titanium dioxide layers.[29] These pigments are coined "interference pigments".[30] In some products, the layer of titanium dioxide is grown in conjunction with iron oxide by calcination of titanium salts (sulfates, chlorates) around 800 °C[31] or other industrial deposition methods

Titanium dioxide 5

such as chemical vapour deposition on substrates which are natural or synthetic mica platelets or even silicon dioxidecrystal platelets of no more than 50 microns in diameter.[32] The iridescent effect in these titanium oxide particles(which are only partly natural ) is unlike the opaque effect obtained with usual ground titanium oxide pigmentobtained by mining, in which case only a certain diameter of the particle is considered and the effect is due only toscattering.In ceramic glazes titanium dioxide acts as an opacifier and seeds crystal formation.Titanium dioxide has been shown statistically to increase skimmed milk's whiteness, increasing skimmed milk'ssensory acceptance score.[33]

Titanium dioxide is used to mark the white lines of some tennis courts.[34]

The exterior of the Saturn V rocket was painted with titanium dioxide; this later allowed astronomers to determinethat J002E3 was the S-IVB stage from Apollo 12 and not an asteroid.

Sunscreen and UV blocking pigments in the industry

In cosmetic and skin care products, titanium dioxide is used as a pigment, sunscreen and a thickener. It is also usedas a tattoo pigment and in styptic pencils. Titanium dioxide is produced in varying particle sizes, oil and waterdispersible, and in certain grades for the cosmetic industry.Titanium dioxide is found in almost every sunscreen with a physical blocker because of its high refractive index, itsstrong UV light absorbing capabilities and its resistance to discolouration under ultraviolet light. This advantageenhances its stability and ability to protect the skin from ultraviolet light. Nano-scaled titanium dioxide particles areprimarily used in sun screen lotion because they scatter visible light less than titanium dioxide pigments while stillproviding UV protection.[] Sunscreens designed for infants or people with sensitive skin are often based on titaniumdioxide and/or zinc oxide, as these mineral UV blockers are believed to cause less skin irritation than other UVabsorbing chemicals.This pigment is used extensively in plastics and other applications not only as a white pigment or an opacifier butalso for its UV resistant properties where the powder disperses the light – unlike organic UV absorbers – andreduces UV damage, due mostly to the extremely high refractive index of the particles.[35] Certain polymers used incoatings for concrete[36] or those used to impregnate concrete as a reinforcement are sometimes charged withtitanium white pigment for UV shielding in the construction industry, but it only delays the oxidativephotodegradation of the polymer in question, which is said to "chalk" as it flakes off due to lowered impact strengthand may crumble after years of exposure in direct sunlight if UV stabilizers have not been included .

Photocatalyst

TiO2 fibers and spirals.

Titanium dioxide, particularly in the anatase form, is a photocatalystunder ultraviolet (UV) light. Recently it has been found that titaniumdioxide, when spiked with nitrogen ions or doped with metal oxide liketungsten trioxide, is also a photocatalyst under either visible or UVlight.[] The strong oxidative potential of the positive holes oxidizeswater to create hydroxyl radicals. It can also oxidize oxygen or organicmaterials directly. Titanium dioxide is thus added to paints, cements,windows, tiles, or other products for its sterilizing, deodorizing andanti-fouling properties and is used as a hydrolysis catalyst. It is alsoused in dye-sensitized solar cells, which are a type of chemical solarcell (also known as a Graetzel cell).

The photocatalytic properties of titanium dioxide were discovered by Akira Fujishima in 1967[37] and published in 1972.[38] The process on the surface of the titanium dioxide was called the Honda-Fujishima effect.[37] Titanium

Titanium dioxide 6

dioxide has potential for use in energy production: as a photocatalyst, it can carry out hydrolysis; i.e., break waterinto hydrogen and oxygen. Were the hydrogen collected, it could be used as a fuel. The efficiency of this process canbe greatly improved by doping the oxide with carbon.[39] Further efficiency and durability has been obtained byintroducing disorder to the lattice structure of the surface layer of titanium dioxide nanocrystals, permitting infraredabsorption.[40]

Titanium dioxide can also produce electricity when in nanoparticle form. Research suggests that by using thesenanoparticles to form the pixels of a screen, they generate electricity when transparent and under the influence oflight. If subjected to electricity on the other hand, the nanoparticles blacken, forming the basic characteristics of aLCD screen. According to creator Zoran Radivojevic, Nokia has already built a functional 200-by-200-pixelmonochromatic screen which is energetically self-sufficient.In 1995 Fujishima and his group discovered the superhydrophilicity phenomenon for titanium dioxide coated glassexposed to sun light.[37] This resulted in the development of self-cleaning glass and anti-fogging coatings.TiO2 incorporated into outdoor building materials, such as paving stones in noxer blocks[41] or paints, cansubstantially reduce concentrations of airborne pollutants such as volatile organic compounds and nitrogenoxides.[42]

A photocatalytic cement that uses titanium dioxide as a primary component, produced by Italcementi Group, wasincluded in Time's Top 50 Inventions of 2008.[43]

Attempts have been made to photocatalytically mineralize pollutants (to convert into CO2 and H2O) in waste water.[]

TiO2 offers great potential as an industrial technology for detoxification or remediation of wastewater due to severalfactors:[44]

1.1. The process uses natural oxygen and sunlight and thus occurs under ambient conditions; it is wavelengthselective and is accelerated by UV light.

2.2. The photocatalyst is inexpensive, readily available, non-toxic, chemically and mechanically stable, and has a highturnover.

3. The formation of photocyclized intermediate products, unlike direct photolysis techniques, is avoided.4. Oxidation of the substrates to CO2 is complete.5. TiO2 can be supported on suitable reactor substrates.

Electronic data storage mediumIn 2010, researchers at the University of Tokyo, Japan have created a crystal form of titanium oxide with particles 5to 20 nanometers that can be switched between two states with light. Use of the 5 nm particles could theoreticallylead to a 25 TB storage disc.[45]

Other applications

Titanium dioxide 7

Synthetic single crystals of TiO2, ca. 2–3 mm insize, cut from a larger plate.

• Titanium dioxide in solution or suspension can be used to cleaveprotein that contains the amino acid proline at the site where prolineis present. This breakthrough in cost-effective protein splitting tookplace at Arizona State University in 2006.[46]

• Titanium dioxide is also used as a material in the memristor, a newelectronic circuit element. It can be employed for solar energyconversion based on dye, polymer, or quantum dot sensitizednanocrystalline TiO2 solar cells using conjugated polymers as solidelectrolytes.[47]

• Synthetic single crystals and films of TiO2 are used as asemiconductor,[48] and also in Bragg-stack style dielectric mirrorsdue to the high refractive index of TiO2 (2.5–2.9).[49][50]

Health and safetyTitanium dioxide is incompatible with strong reducing agents and strong acids.[] Violent or incandescent reactionsoccur with molten metals that are very electropositive, e.g. aluminium, calcium, magnesium, potassium, sodium,zinc and lithium.[]

Titanium dioxide accounts for 70% of the total production volume of pigments worldwide. It is widely used toprovide whiteness and opacity to products such as paints, plastics, papers, inks, foods, and toothpastes. It is also usedin cosmetic and skin care products, and it is present in almost every sunblock, where it helps protect the skin fromultraviolet light.Many sunscreens use nanoparticle titanium dioxide (along with nanoparticle zinc oxide) which, despite reports ofpotential health risks,[51] is not actually absorbed through the skin.[52] Other effects of titanium dioxide nanoparticleson human health are not well understood.[53] Nevertheless, allergy to topical application has been confirmed.[54]

Titanium dioxide dust, when inhaled, has been classified by the International Agency for Research on Cancer(IARC) as an IARC Group 2B carcinogen, meaning it is possibly carcinogenic to humans.[] The findings of theIARC are based on the discovery that high concentrations of pigment-grade (powdered) and ultrafine titaniumdioxide dust caused respiratory tract cancer in rats exposed by inhalation and intratracheal instillation.[55] The seriesof biological events or steps that produce the rat lung cancers (e.g. particle deposition, impaired lung clearance, cellinjury, fibrosis, mutations and ultimately cancer) have also been seen in people working in dusty environments.Therefore, the observations of cancer in animals were considered, by IARC, as relevant to people doing jobs withexposures to titanium dioxide dust. For example, titanium dioxide production workers may be exposed to high dustconcentrations during packing, milling, site cleaning and maintenance, if there are insufficient dust control measuresin place. However, the human studies conducted so far do not suggest an association between occupational exposureto titanium dioxide and an increased risk for cancer. The safety of the use of nano-particle sized titanium dioxide,which can penetrate the body and reach internal organs, has been criticized.[56] Studies have also found that titaniumdioxide nanoparticles cause inflammatory response and genetic damage in mice.[57][58] The mechanism by whichTiO2 may cause cancer is unclear. Molecular research suggests that cell cytotoxicity due to TiO2 results from the interaction between TiO2 nanoparticles and the lysosomal compartment, independently of the known apoptotic signalling pathways.[59]

There is some evidence the rare disease Yellow nail syndrome may be caused by titanium, either implanted formedical reasons or through eating various foods containing titanium dioxide.[]

Titanium dioxide 8

References[1] http:/ / www. commonchemistry. org/ ChemicalDetail. aspx?ref=13463-67-7[2] http:/ / pubchem. ncbi. nlm. nih. gov/ summary/ summary. cgi?cid=26042[3] http:/ / www. chemspider. com/ 24256[4] http:/ / fdasis. nlm. nih. gov/ srs/ srsdirect. jsp?regno=15FIX9V2JP[5] http:/ / www. kegg. jp/ entry/ C13409[6] https:/ / www. ebi. ac. uk/ chebi/ searchId. do?chebiId=32234[7] https:/ / www. ebi. ac. uk/ chembldb/ index. php/ compound/ inspect/ CHEMBL1201136[8] http:/ / chemapps. stolaf. edu/ jmol/ jmol. php?model=O%3D%5BTi%5D%3DO[9] http:/ / www. inchem. org/ documents/ icsc/ icsc/ eics0338. htm[10] http:/ / en. wikipedia. org/ w/ index. php?title=Special:ComparePages& rev1=476992554& page2=Titanium+ dioxide[30] http:/ / www. impactcolorsinc. com/ Optique-Iridescence[32] Pearlescence with Iriodin (http:/ / pearl-effect. com/ index. php?option=com_content& view=article& id=92& Itemid=62). pearl-effect.com[34] Les, Caren B. (November 2008) Light spells doom for bacteria (http:/ / www. photonics. com/ Article. aspx?AID=35722). Photonics.com[35] Polymers, Light and the Science of TiO2 (http:/ / www2. dupont. com/ Titanium_Technologies/ en_US/ tech_info/ literature/ Plastics/

PL_B_Polymers_Light_Science. pdf), DuPont, pp. 1–2[36] Fibre Cement Coating (http:/ / www. dowconstructionchemicals. com/ eu/ en/ applications/ fibercementcoat).

dowconstructionchemicals.com[37] "Japan Nanonet Bulletin – 44th Issue – May 12, 2005: Discovery and applications of photocatalysis —Creating a comfortable future by

making use of light energy" (http:/ / www. nanonet. go. jp/ english/ mailmag/ 2005/ 044a. html)[40] Cheap, Clean Ways to Produce Hydrogen for Use in Fuel Cells? A Dash of Disorder Yields a Very Efficient Photocatalyst (http:/ / www.

sciencedaily. com/ releases/ 2011/ 01/ 110128165212. htm). Sciencedaily (2011-01-28)[41] Advanced Concrete Pavement materials, page 435 http:/ / www. cptechcenter. org/ publications/ task15/ task15_vol2/ track12am. pdf[42] Hogan, Jenny (2004-02-04) Smog-busting paint soaks up noxious gases (http:/ / www. newscientist. com/ article/ dn4636). New Scientist.[43] TIME's Best Inventions of 2008 (http:/ / www. time. com/ time/ specials/ packages/ article/ 0,28804,1852747_1854195_1854176,00. html).

(2008-10-31).

External links• International Chemical Safety Card 0338 (http:/ / www. inchem. org/ documents/ icsc/ icsc/ eics0338. htm)• "Nano-Oxides, Inc. – Nano Powders, LEGIT information on Titanium Dioxide TiO2" (http:/ / www. nano-oxides.

com/ pdf/ TiO2_Brochure. pdf). www.nano-oxides.com. Retrieved November2008.• NIOSH Pocket Guide to Chemical Hazards (http:/ / www. cdc. gov/ niosh/ npg/ npgd0617. html)• "Fresh doubt over America map", bbc.co.uk, 30 July 2002 (http:/ / news. bbc. co. uk/ 1/ hi/ health/ 2162248. stm)• Titanium Dioxide Classified as Possibly Carcinogenic to Humans, 2007 (http:/ / www. ccohs. ca/ headlines/

text186. html) (if inhaled as a powder)• A description of TiO2 photocatalysis (http:/ / www. threebond. co. jp/ en/ technical/ technicalnews/ pdf/ tech62.

pdf)• Crystal structures of the three forms of TiO2 (http:/ / ruby. colorado. edu/ ~smyth/ min/ tio2. html)• "Architecture in Italy goes green", Elisabetta Povoledo, International Herald Tribune, November 22, 2006 (http:/

/ www. iht. com/ articles/ 2006/ 11/ 22/ news/ smog. php)• "A Concrete Step Toward Cleaner Air", Bruno Giussani, BusinessWeek.com, November 8, 2006 (http:/ / www.

businessweek. com/ innovate/ content/ nov2006/ id20061108_116412. htm?campaign_id=bier_innv. g3a.rss1109c)

• "Titanium Dioxide Classified as Possibly Carcinogenic to Humans", Canadian Centre for Occupational Healthand Safety, August, 2006 (http:/ / www. ccohs. ca/ headlines/ text186. html)

• Sunscreen in the Sky? Reflective Particles May Combat Warming (http:/ / news. nationalgeographic. com/ news/2012/ 05/ 120529-global-warming-titanium-dioxide-balloons-earth-environment-science/ )

• Titanium and titanium dioxide production data (US and World) (http:/ / minerals. usgs. gov/ minerals/ pubs/commodity/ titanium/ mcs-2012-titan. pdf)

Article Sources and Contributors 9

Article Sources and ContributorsTitanium dioxide  Source: http://en.wikipedia.org/w/index.php?oldid=559478495  Contributors: 28bytes, 3-14159, A13ean, ABlagus, Abbis, Acalamari, Afluegel, Ahw001, Aksi great, Alnokta,Altenmann, Antrax, Anyeverybody, Anypodetos, Arcadie, ArnoldReinhold, Asterion, Atomlinking, Axiosaurus, B07, Badagnani, Bdsmith, Beetstra, BeingTheDoor, Belfry, Benbest,Benjah-bmm27, Bkrosnov, BrainMafia, Briefexact22, BrotherFlounder, Bsadowski1, Cacycle, CharlesC, Cheakamus, Chem-awb, Christian75, Cstreet, D0nj03, DSachan, Daggerbox, Danh,David J Herman, Dcirovic, Dekimasu, DeminJanu, DocWatson42, DrBob, Ebe123, Edgar181, Edsanville, Edwardaggie98, Elamyn01, Ellywa, Elysdir, EncMstr, Eric Ch, Ewlyahoocom, Ewulp,Femto, Frap, Fratrep, Freakert, Freder1ck, Furminger, Fygoat, Gaius Cornelius, Giftlite, Gilliam, Gordonchristie, Griffj91, Habtom D Asfaw, Hairy Dude, HappyInGeneral, Heron, Hervold,HexaChord, Iantresman, Ikh, Isabel100, Isnow, Issius, IstvanWolf, Itsypitsy, JQF, Jawz, John Nevard, JohnOwens, JohnSRoberts99, Jouster, Julesd, Kashmiri, Katieh5584, Keenan Pepper, KeithEdkins, Kenibale, Khazar2, Kkmurray, Kmrtdsc, Kraminator, Kungfuadam, LDHan, Lamro, Lee Carre, LegacyOfValor, Leszek Jańczuk, Lights, Lincolnite, Listrophy, Looxix, Louisajb,Lugia2453, Lyla1205, Macaddct1984, Master Jay, Materialscientist, Maximaximax, Melos Antropon, Mhking, Mike 7, Mintleaf, Mion, Moisture, Mordicai, Mpete510, Murtasa, Mwanner,MysticMetal, Nano2007, Nanoak, NawlinWiki, Ninetyone, Nopetro, Northfox, Northumbrian, Nutriveg, Nxn, OhanaUnited, Omicronpersei8, Oxymoron83, Pacula, Pashihiko, Paul Drye,Peruvianllama, Pgk, Physchim62, Physicsisshiny, Piano non troppo, Picklesandcereal, Pilotguy, Pineappleleaf, Pinethicket, Poppy, Prari, Rehman, Rich Farmbrough, Rifleman 82, Riley Huntley,Rjwilmsi, Rmowat1983, Rmowat83, Roadrunner, Rockstone35, Rod57, Rogper, Ronhjones, RoyBoy, Rycecube57, STarry, Salvor, Sbyrnes321, Schmloof, Scientist 42, Securiger, Shaddack,Shadowjams, Shigeyuki.miyata, Shoefly, Shoy, Simon.templar, SkepticalRaptor, Slashme, Smokefoot, Snosty, Sophieozz, Srleffler, Ssilvers, Ssri1983, Stan Shebs, Ste nohype, Surfacechem2011,Sweety2012, Swpb, TDogg310, Tbhotch, The Famous Movie Director, Thingg, Thricecube, Thumperward, Tim Starling, Torsionalmetric, Tt 225, Turgonml, Tuyend, Utcursch, V8rik, VMSMosaic, Vargenau, Venajaguardian, Vsmith, Vuo, Walkerma, WaysToEscape, Wikiman232, Woland82, Wumbla, YixilTesiphon, Zaphraud, 412 anonymous edits

Image Sources, Licenses and ContributorsImage:Titanium(IV)_oxide.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Titanium(IV)_oxide.jpg  License: unknown  Contributors: Original uploader was Walkerma aten.wikipediaImage:Rutile-unit-cell-3D-balls.png  Source: http://en.wikipedia.org/w/index.php?title=File:Rutile-unit-cell-3D-balls.png  License: Public Domain  Contributors: Ben MillsFile:Yes check.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Yes_check.svg  License: Public Domain  Contributors: AnomieFile:X mark.svg  Source: http://en.wikipedia.org/w/index.php?title=File:X_mark.svg  License: Public Domain  Contributors: User:GmaxwellFile:TiO2nanotube.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:TiO2nanotube.jpg  License: Creative Commons Attribution-Sharealike 2.0  Contributors: Argonne NationalLaboratoryFile:Titanium dioxide nanofiber spiral.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Titanium_dioxide_nanofiber_spiral.jpg  License: Creative Commons Attribution-Sharealike2.0  Contributors: Kunal MukherjeeFile:TiO2crystals.JPG  Source: http://en.wikipedia.org/w/index.php?title=File:TiO2crystals.JPG  License: Creative Commons Attribution-Sharealike 3.0  Contributors: Materialscientist (talk).Original uploader was Materialscientist at en.wikipedia

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