Sodium lauryl sulfate 54201 225639046 2008-07-14T18:01:56Z Benjah-bmm27 126395 new [[ball-and-stick model]] (based on the crystal structure) added {{Chembox new | Name = Sodium dodecyl sulfate | ImageFile = SDS-2D-skeletal.png | ImageSize = 300 | ImageFile1 = SDS-sheet-3D-balls.png | ImageSize1 = 300 | IUPACName = Sodium dodecyl sulfate | OtherNames = Sodium monododecyl sulfate; Sodium lauryl sulfate; Sodium monolauryl sulfate; Sodium dodecanesulfate; dodecyl alcohol, hydrogen sulfate, sodium salt; n-dodecyl sulfate sodium; Sulfuric acid monododecyl ester sodium salt; | Section1 = {{Chembox Identifiers | CASNo = 151-21-3 | SMILES = CCCCCCCCCCCCOS(=O)([O-])=O.[Na+] }} | Section2 = {{Chembox Properties | Formula = Na</sub>C<sub>12</sub>H<sub>25</sub>S</sub>O<sub>4 | MolarMass = 288.38 g mol<sup>−1</sup> | Density = 1.01 g/cm³ | MeltingPt = 206 °C | BoilingPt = }} }} '''Sodium lauryl sulfate''' ('''SLS''') or '''sodium dodecyl sulfate''' ('''SDS''' or NaDS) ([[carbon|C]]<sub>12</sub>[[hydrogen|H]]<sub>25</sub>[[sulfur|S]][[oxygen|O]]<sub>4</sub>[[sodium|Na]]) is an [[anion]]ic [[surfactant]] that is used in industrial products including engine degreasers, floor cleaners, and car wash soaps; as well as in household products such as [[toothpaste]]s, [[shampoo]]s, [[shaving foam]]s, some dissolvable [[aspirin]]s, fiber therapy caplets, and [[bubble bath]]s for its thickening effect and its ability to create a lather. The molecule has a tail of 12 carbon atoms, attached to a [[sulfate]] group, giving the molecule the [[amphiphilic]] properties required of a [[detergent]]. ==Preparation== Sodium lauryl sulfate is prepared by [[esterification]] of [[sulfuric acid]] with [[dodecanol]] (lauryl alcohol, C<sub>12</sub>H<sub>25</sub>OH), followed by neutralization with [[sodium carbonate]].<ref>{{cite web | publisher = Chemicalland21 | url = http://chemicalland21.com/specialtychem/perchem/SODIUM%20LAURYL%20SULFATE.htm | title = Sodium Lauryl Sulfate}}</ref> It is used in both industrially produced and home-made cosmetics. ==Applications== Sodium lauryl sulfate is probably the most researched anionic surfactant compound. Like all [[detergent]] surfactants (including [[soap]]s), sodium lauryl sulfate removes oils from the [[skin]], and can cause skin and eye irritation. The [[critical micelle concentration]] in pure water at 25°C is 0.0082 M, and the [[aggregation number]] at this concentration is usually considered to be about 50. The micelle ionization fraction (α) is around 0.3 (or 30%).<ref name="Barney_L">{{cite journal | author = Barney L. Bales, Luis Messina, Arwen Vidal, Miroslav Peric, and Otaciro Rangel Nascimento | title = Precision Relative Aggregation Number Determinations of SDS Micelles Using a Spin Probe. A Model of Micelle Surface Hydration | journal = [[J. Phys. Chem.]] B | year = 1998 | volume = 102 | issue = 50 | pages = 10347–10358 | doi = 10.1021/jp983364a}}</ref> It has recently found application as a surfactant in [[gas hydrate]] or [[methane hydrate]] formation reactions, increasing the rate of formation as much as 700 times.<ref name="Kazuyoshi">Kazuyoshi Watanabe, Shuntaro Imai and Yasuhiko H. Mori. Surfactant effects on hydrate formation in an unstirred gas/liquid system: An experimental study using HFC-32 and sodium dodecyl sulfate. Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522. ''Japan.Chemical Engineering Science.'' Volume 60, Issue 17, September 2005, Pages 4846-4857. [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFK-4G7X9W5-6&_user=10&_coverDate=09%2F30%2F2005&_alid=442706800&_rdoc=1&_fmt=summary&_orig=browse&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a323a5a6de479105ae8ddd8dd87162f3 Abstract]</ref> ===SDS-PAGE=== {{main|SDS-PAGE}} Sodium lauryl sulfate is commonly used in preparing [[proteins]] for electrophoresis in the SDS-PAGE technique.<ref>The acronym expands to "sodium dodecyl sulfate-polyacrylamide gel electrophoresis.</ref> This compound works by disrupting non-covalent bonds in the proteins, denaturing them, and causing the molecules to lose their native shape (conformation). Also, anions of SLS bind to the main [[peptide]] chain at a ratio of one SLS anion for every two [[amino acid]] residues. This effectively imparts a negative charge on the [[protein]] that is proportional to the mass of that protein (about 1.4 g SLS/g protein). This new negative charge is significantly greater than the original charge of that protein. The [[electrostatic repulsion]] that is created by binding of SLS causes proteins to unfold into a rod-like shape thereby eliminating differences in shape as a factor for separation in the gel. ==Reactions== SLS can be converted by [[ethoxylation]] to [[sodium laureth sulfate]] (sodium lauryl ether sulfate; SLES), which is less harsh on the skin, probably because it is not as much of a protein denaturant as is the unethoxylated substance.{{Fact|date=May 2008}} ==Safety== When handling SLS in its solid form use extreme caution, the compound easily particalizes into the air. If inhaled can cause a serious choking hazard. A number of health concerns about SLS have been raised in published reports.<ref name="Agner_T">Agner T. Susceptibility of atopic dermatitis patients to irritant dermatitis caused by sodium lauryl sulphate. ''Acta Derm Venereol.'' 1991;71(4):296-300. PMID 1681644</ref><ref name="A._Nassif_1994">A. Nassif, S. C. Chan, F. J. Storrs and J. M. Hanifin. Abstract: Abnormal skin irritancy in atopic dermatitis and in atopy without dermatitis. ''Arch Dermatol.'' November 1994;130(11):1402. [http://archderm.ama-assn.org/cgi/content/abstract/130/11/1402 Abstract]</ref><ref name="Marrakchi_S">Marrakchi S, Maibach HI. Sodium lauryl sulfate-induced irritation in the human face: regional and age-related differences. ''Skin Pharmacol Physiol.'' 2006;19(3):177-80. Epub 2006 May 4. PMID 16679819</ref> These studies indicate that: * SLS may cause a number of skin problems (for which the non-specific term is ''[[dermatitis]]''), with some people being affected more than others.<ref name="Marrakchi_S"/><ref name="Final_Report_SLS">CIR publication. Final Report on the Safety Assessment of Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate. ''Journal of the American College of Toxicology.'' 1983 Vol. 2 (No. 7) pages 127-181.</ref><ref name="Loffler_H">Loffler H, Effendy I. Skin susceptibility of atopic individuals. Department of Dermatology, University of Marburg, Germany. ''Contact Dermatitis.'' 1999 May;40(5):239-42. PMID 10344477</ref> * SLS in toothpaste may cause [[aphthous ulcer]]s, commonly referred to in some countries as "[[canker sores]]".<ref>{{cite journal | author = Herlofson B, Barkvoll P | title = Sodium lauryl sulfate and recurrent aphthous ulcers. A preliminary study. | journal = Acta Odontol Scand | volume = 52 | issue = 5 | pages = 257–9 | year = 1994 | pmid=7825393 | url=http://www.wealthpartners.net/pdf/0535.pdf | format=PDF | doi = 10.3109/00016359409029036 <!--Retrieved from CrossRef by DOI bot-->}}</ref><ref name="Chahine_L">Chahine L, Sempson N, Wagoner C. The effect of sodium lauryl sulfate on recurrent aphthous ulcers: a clinical study. ''Compend Contin Educ Dent.'' 1997 Dec;18(12):1238-40. PMID 9656847</ref><ref name="Herlofson_BB">Herlofson BB, Barkvoll P. The effect of two toothpaste detergents on the frequency of recurrent aphthous ulcers. ''Acta Odontol Scand.'' 1996 Jun;54(3):150-3. PMID 8811135</ref> However, some studies find no connection between SLS in toothpaste and mouth ulcers.<ref>{{cite journal | author = Healy C, Paterson M, Joyston-Bechal S, Williams D, Thornhill M | title = The effect of a sodium lauryl sulfate-free dentifrice on patients with recurrent oral ulceration. | journal = Oral Dis | volume = 5 | issue = 1 | pages = 39–43 | year = 1999 | pmid=10218040 | doi = 10.1111/j.1365-2133.2005.06490.x}}</ref> ==See also== * [[Ammonium lauryl sulfate]] ==References== {{reflist|2}} ==External links== * [http://tomsofmaine.custhelp.com/cgi-bin/tomsofmaine.cfg/php/enduser/std_adp.php?p_faqid=2&p_created=1158586355&p_sid=ed3QIp*i&p_accessibility=0&p_redirect=&p_lva=&p_sp=cF9zcmNoPSZwX3NvcnRfYnk9JnBfZ3JpZHNvcnQ9JnBfcm93X2NudD05Miw5MiZwX3Byb2RzPSZwX2NhdHM9JnBfcHY9JnBfY3Y9JnBfc2VhcmNoX3R5cGU9YW5zd2Vycy5zZWFyY2hfbmwmcF9wYWdlPTE*&p_li=&p_topview=1 Tom of Maine's FAQ: Is sodium lauryl sulfate (SLS) safe for use?] * [http://www.snopes.com/inboxer/household/shampoo.asp Urban Legends Reference Pages: Shampoo Sham, snopes.com] [[Category:Organosulfates]] [[Category:Sodium compounds]] [[Category:Cleaning product components]] [[Category:Surfactants]] [[ar:دوديسيل كبريتات صوديوم]] [[da:Natriumlaurylsulfat]] [[de:Natriumlaurylsulfat]] [[es:Dodecilsulfato sódico]] [[fr:Laurylsulfate de sodium]] [[ko:라우릴 황산 나트륨]] [[it:Laurilsolfato di sodio]] [[nl:Natriumdodecylsulfaat]] [[ja:ラウリル硫酸ナトリウム]] [[pl:Dodecylosiarczan sodu]] [[pt:Dodecil sulfato de sódio]] [[ru:SDS (химия)]] [[fi:Natriumlauryylisulfaatti]] [[sv:Natriumdodecylsulfat]] [[uk:Додецилсульфат натрію]] [[zh:十二烷基硫酸钠]]