Aluminium sulfacetate
Aluminium sulfacetateis a mixture ofaluminiumsalts dissolved in water with formulaAl
2SO
4(CH
3CO
2)
4.[1][2]
Uses
[edit]It is an evenly balanced mixture ofaluminium sulfateandaluminium acetate.It can be used as amordant,which is a substance used to setdyeson fabrics[3]that typically contains apolyvalentmetal ion like aluminium or iron,[4]In mixtures withbasic aluminium diacetateor aluminium sulfacetate, aluminium triacetate has been used as a mordant withalizarindye.[1]In 1899, Albert Ganswindt recommended that the use of impure sulfacetates that are empyreumatic liquids "should be abandoned" in favour of pure preparations.[5]Empyreumais an obsolete chemical and medical term referring to "the smell and taste associated with burning vegetable and animal matter",[6]and likely results in this case from the use ofpyroligneous acid(wood acid) or wood acid lime in the preparation of the mordant.[5]
Preparation
[edit]A common approach to preparing aluminium sulfacetate is by reaction of aluminium sulfate withlead(II) acetate.The relative amount of each reagent controls the composition of the resulting mixture.[1]When thestoichiometric ratioof lead acetate to aluminium sulfate exceeds 3:1, the process is theoretically driven to completion and aluminium triacetate is the sole product. With less lead acetate, a mixture of aluminium triacetate and aluminium sulfacetate results that becomes increasingly rich in the latter as the reagentmoleratio approaches 2:1. This approach is used to form various mixtures for mordant applications:[1]
- Al
2(SO
4)
3+ 3Pb(CH
3CO
2)
2→ 2Al(CH
3CO
2)
3+ 3PbSO
4
Basic aluminiumsulfacetates can also be prepared,Al
2SO
4(CH
3CO
2)
4 -n(OH)
n,withhydroxideanions replacing someacetateions. The extreme cases are aluminium sulfacetate itself (n= 0) and the double salt of aluminium sulfate andaluminium hydroxide(n= 4 case,Al
2SO
4(OH)
4). Aluminium sulfacetate is made from thehydratesof aluminium sulfate and lead acetate:[2]
- Al
2(SO
4)
3•18H
2O+ 2Pb(CH
3CO
2)
2•3H
2O→Al
2SO
4(CH
3CO
2)
4+ 2PbSO
4+ 24H
2O
Then= 1 andn= 2 cases, both of which are basic aluminium sulfacetates, are prepared usingsodium bicarbonatealong with the regents:[2]
- 2Al
2(SO
4)
3•18H
2O+ 3Pb(CH
3CO
2)
2•3H
2O+ 2NaHCO
3→Al
2SO
4(CH
3CO
2)
3OH+ 3PbSO
4+Na
2SO
4+ 2CO
2+ 45H
2O
- Al
2(SO
4)
3•18H
2O+Pb(CH
3CO
2)
2•3H
2O+ 2NaHCO
3→Al
2SO
4(CH
3CO
2)
2(OH)
2+PbSO
4+Na
2SO
4+ 2CO
2+ 21H
2O
Then= 3 case, also a basic aluminium sulfacetate, is prepared usingacetic acidinstead of lead acetate, along with sodium bicarbonate:[2]
- Al
2(SO
4)
3•18H
2O+CH
3COOH+ 4NaHCO
3→Al
2SO
4(CH
3CO
2)(OH)
3+ 2Na
2SO
4+CO
2+ 19H
2O
References
[edit]- ^abcdvon Georgievics, Georg (2013).The Chemical Technology of Textile Fibres – Their Origin, Structure, Preparation, Washing, Bleaching, Dyeing, Printing and Dressing.Read Books.ISBN9781447486121.
- ^abcdHummel, J. J.; Knecht, Edmund (1888).Die Färberei und Bleicherei der Gespinnstfasern(in German).Springer-Verlag.pp. 116–118.ISBN9783642912061.
- ^IUPAC,Compendium of Chemical Terminology,2nd ed. (the "Gold Book" ) (1997). Online corrected version: (2006–) "Mordant".doi:10.1351/goldbook.M04029
- ^Llewellyn, Bryan D. (May 2005)."Stain Theory – How mordants work".Archived fromthe originalon 14 August 2007.
- ^abGanswindt, Albert (1889).Handbuch der Färberei und der damit verwandten vorbereitenden und vollendenden Gewerbe(in German). p. 270.
- ^"Definition of empyreuma".Collins Dictionary.2016.Retrieved23 November2016.