Sodium dodecyl sulfate

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Sodium dodecyl sulfate
Sodium dodecyl sulfate bottle sample.jpg
Sodium dodecyl sulfate bottle and sample.
Names
IUPAC name
Sodium dodecyl sulfate
Other names
Sodium dodecanesulfate
Sodium lauryl sulfate
Sodium monododecyl sulfate
Sodium monolauryl sulfate
Properties
C12H25SO4Na
Molar mass 288.372 g/mol
Appearance White solid
Odor Odorless
Density 1.01 g/cm3
Melting point 206 °C (403 °F; 479 K)
Boiling point Decomposes
0.1 g/100 ml
Hazards
Safety data sheet Sigma-Aldrich
Lethal dose or concentration (LD, LC):
1,288 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium dodecyl sulfate (SDS) or more commonly sodium lauryl sulfate (SLS), is an organic compound with the formula CH3(CH2)11SO4Na. It is widely used as anionic surfactant in many cleaning and hygiene products.

Properties

Chemical

SLS is the sodium salt of a 12-carbon alcohol that has been esterified to sulfuric acid. An alternative description is that it is an alkyl group with a pendant, terminal sulfate group attached. As a result of its hydrocarbon tail, and its anionic "head group", it has amphiphilic properties that allow it to form micelles, and so act as a detergent.

SLS can be oxidized using oxidizing mixtures like aqua regia to carbon dioxide and water

Physical

Sodium lauryl sulfate is a white solid, slightly soluble in water.

Availability

Pure sodium lauryl sulfate can be bought online or from chemical suppliers.

Preparation

Sodium dodecyl sulfate is synthesized by treating lauryl alcohol (dodecanol) with sulfur trioxide, oleum, or chlorosulfuric acid to produce hydrogen lauryl sulfate, which is neutralized by adding sodium hydroxide or sodium carbonate. Lauryl alcohol can obtained from coconut or palm kernel oil by hydrolysis (which liberates their fatty acids), followed by hydrogenation. If you don't want this route, just use dodecanol.

Projects

  • Use as surfactant
  • DNA extraction
  • Denaturate proteins
  • Microbicide

Handling

Safety

Sodium dodecyl sulfate has low toxicity and it's considered safe for use. Contact with bare skin will remove the oils from it causing irritation.

Storage

SDS should be kept in closed bottles.

Disposal

No special disposal is required for SDS. It can be safely poured down the drain, though it's recommended to dilute it first.

References

Relevant Sciencemadness threads