Opacifier


Opacifier

An opacifier is a substance added to a material in order to make the ensuing system opaque. An example of a chemical opacifier is tin dioxide (SnO2), which is used to opacify ceramic glazes[1] and milk glass; bone ash is also used.

Opacifiers must have a refractive index (RI) substantially different from the system. Conversely, clarity may be achieved in a system by choosing components with very similar refractive indices.[2]

Opacifiers must also form small particles in the system. Opacifiers are generally inert.

Sometimes opacifiers are added to medical implants to make them visible under X-ray imaging. This is especially true in the case of most polymers which are often unrecognizable in the body when viewed using X-rays.

In solid rocket propellants and some translucent smokeless powders, the primary method of heat transfer into the propellant grain from the combustion process is by radiation, and opacifiers such as "lamp black" may be added to the propellant mixture to ensure the heat does not penetrate far below the surface of the grain, which could cause detonation. The opacifiers also prevent sub-surface overheating and localized premature ignition in the grains where imperfections absorbing the thermal radiation are present. Carbon black is commonly used for this purpose; other possible additives are nigrosin, Prussian blue, methylene blue, etc. in amounts ranging commonly between 0.1-0.5%.[3]

References

  1. ^ Tin Oxide ( SnO2 ) Stannic Oxide – Properties and Applications, The A to Z of Materials.
  2. ^ Raghavan, V. (2004). Materials Science and Engineering: A First Course. India: Prentice Hall. ISBN 8120324552. 
  3. ^ US Army - Encyclopedia of Explosives and Related Items, vol.8

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Look at other dictionaries:

  • opacifier — [ ɔpasifje ] v. tr. <conjug. : 7> • 1868; de opaque ♦ Rendre opaque. Pronom. S OPACIFIER : devenir opaque. ● opacifier verbe transitif Rendre un corps opaque, lui enlever sa transparence. opacifier v. tr. Rendre opaque. || v. Pron. Devenir… …   Encyclopédie Universelle

  • opacifier — (o pa si fi é) v. a. Rendre opaque.    S opacifier, v. réfl. Devenir opaque …   Dictionnaire de la Langue Française d'Émile Littré

  • opacifier — drumstiklis statusas T sritis chemija apibrėžtis Medžiaga, kurios dedama į stiklo masę drumstajam stiklui gauti. atitikmenys: angl. opacifier rus. глушитель …   Chemijos terminų aiškinamasis žodynas

  • opacifier — o·pac·i·fi·er (ō păsʹə fī ər) n. A chemical agent added to a material, such as rocket propellant, to make it opaque. * * * …   Universalium

  • opacifier — noun a) A chemical agent added to a material, such as rocket propellant, to make it opaque. b) An extraneous agent or vehicle which, intentionally otherwise, makes something opaque. See Also: opacif …   Wiktionary

  • opacifier — n. chemical agent added to a material in order to turn it opaque …   English contemporary dictionary

  • opacifier — opaci·fi·er …   English syllables

  • opacifier —  ̷ ̷ˈ ̷ ̷ ̷ ̷ˌfī(ə)r noun ( s) : a constituent or additive (as of an enamel, a paint, a glass) that tends to opacify the system of which it is a part …   Useful english dictionary

  • opacification — [ ɔpasifikasjɔ̃ ] n. f. • 1810; de opacifier ♦ Méd. 1 ♦ Diminution de la transparence de la cornée (⇒ albugo, leucome, néphélion, taie), ou du cristallin (⇒ 2. cataracte ). 2 ♦ Injection d une substance opaque aux rayons X en vue d un examen… …   Encyclopédie Universelle

  • opacifia — OPACIFIÁ, opacifiez, vb. I. refl. A deveni opac2, a se face opac2. [pr.: fi a] – Din fr. opacifier. Trimis de oprocopiuc, 07.05.2004. Sursa: DEX 98  opacifiá vb. (sil. fi a), ind. prez. 1 sg …   Dicționar Român


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