Contributors: Sophie Carman
Alkaline refers to a solution or material that contains a base.
Synonyms in English
Alkaline is synonymous with the term “base,” referring to a solution or material that has a pH greater than 7 (Getty: Alkalinity). The logarithmic pH scale is used to measure alkalinity. (Museum of Fine Arts Boston: pH). Bases (alkaline materials) have a pH greater than 7 (a pH of 7 being neutral) and increase in alkalinity as the pH approaches 14 (Museum of Fine Arts Boston: Alkaline). For example, a pH of 6.9 indicates a very weak acid, whereas a pH of 0 (zero) indicates a very strong acid. Alkalinity is opposed to acidity, which refers to a solution that has a pH less than 7 (Getty: Acidity). Examples of bases used in conservation include sodium hydroxide, sodium carbonate, etc.
Alkaline can also refer to an environmental condition. Alkaline environments can be created by low rainfall and high evaporation, as in arid and semi-arid (Cronyn 1990). This type of environment allows bases in dissolving rock particles to remain in place instead being washed out by rainwater. Sea-water has a pH of 8.2 and is also considered to be an alkaline environment. Such environments are favorable to metals but can be destructive to organic materials.
“Acidity.” Getty. Accessed April 1st, 2014. http://www.getty.edu/vow/AATServlet?english=N&find=acidity&logic=AND&page=1¬e=
“Alkaline.” Museum of Fine Arts Boston. Accessed April 1st, 2014. http://cameo.mfa.org/wiki/Alkaline
“Alkalinity.” Getty. Accessed April 1st, 2014. http://www.getty.edu/vow/AATServlet?english=N&find=alkalinity&logic=AND&page=1¬e
Cronyn, J. M. 1990. The Elements of Archaeological Conservation. London: Routledge.
“pH.” Museum of Fine Arts Boston. Accessed April 1st, 2014. http://cameo.mfa.org/wiki/PH