Aluminium hydroxide



Aluminium hydroxide
IUPAC name Aluminium(III) hydroxide
Other names Aluminium hydroxide,
Hydrated alumina
Identifiers
CAS number 21645-51-2
Properties
Molecular formula Al(OH)3
Molar mass 78.00344 g/mol
Appearance White amorphous powder.
Density 2.4 g/cm³, solid.
Melting point

300°C

Solubility in water Insoluble.
Hazards
MSDS External MSDS
EU classification Irritant (I)
R-phrases R36, R37, R38
S-phrases S36
Flash point Non-flammable.
Related Compounds
Other anions None.
Related compounds Sodium oxide,
aluminium oxide hydroxide.
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Aluminium hydroxide, Al(OH)3, is the most stable form of aluminium in normal conditions. It is found in nature as the mineral bauxite.

Chemistry

Gibbsite has a typical metal hydroxide structure with hydrogen bonds. It is built up of double layers of hydroxyl groups with aluminum ions occupying two-thirds of the octahedral holes between the two layers.[1]

Aluminum hydroxide is alkali, forming Al(OH)4-.

Aluminum hydroxide is produced in the Bayer process as an intermediate in the production of aluminum metal.

Pharmacology

Pharmacologically, this compound is used as an magnesium carbonate, which has counterbalancing laxative effects. This compound is also used to control phosphate levels in the blood of people suffering from kidney failure.

Aluminium hydroxide is included as an adjuvant in some vaccines (e.g., Alhydrogel), since it contributes to induction of a good antibody (Th2) response. However, it has little capacity to stimulate cellular (Th1) immune responses, important for protection against many pathogens (Petrovsky and Aguilar, 2004).

Because the brain lesions found in Alzheimer's disease contain aluminium, there is concern that consumption of excess aluminium compounds may cause or contribute to the development of this and other neurodegenerative diseases (Perl, 2006, Kawahara, 2005). In addition, elevated aluminium levels in blood, resulting from kidney dialysis with well water containing high aluminium, result in dementia that is similar to but probably different from that of Alzheimer's disease (Carpenter, 2001). However, this hypothesis is controversial.

References

  1. ^ A. F. Wells, Structural Inorganic Chemistry, 4th. edition 1975, Oxford University Press.

Carpenter DO. Effects of metals on the nervous system of humans and animals. Int J Occup Med Environ Health. 2001;14(3):209-18.

Galbraith, A; Bullock, S; Manias, E. Hunt, B. & Richards, A. (1999). Fundamentals of pharmacology: a text for nurses and health professionals. Harlow: Pearson Education Ltd. p482.

Kawahara M. Effects of aluminum on the nervous system and its possible link with neurodegenerative diseases. J Alzheimers Dis. 2005 Nov;8(2):171-82; discussion 209-15.

Perl DP, Moalem S. Aluminum and Alzheimer's disease, a personal perspective after 25 years. J Alzheimers Dis. 2006;9(3 Suppl):291-300.

Petrovsky N, Aguilar JC. Vaccine adjuvants: current state and future trends. Immunol Cell Biol. 2004 Oct;82(5):488-96.

 
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