Date palm juice inhibited corrosion of an aluminum alloy called AA7075, used in aerospace and other applications, in a salt solution, according to a new study by Husnu Gerengi at Duzce University in Turkey. His paper is published in the ACS journal Industrial & Engineering Chemistry.
Aluminum corrodes when exposed to air, but unlike rusting steel, the corrosion of aluminum’s surface layer forms a protective film that prevents degradation of the underlying metal. However, that film breaks down in some harsh environments, such as seawater, leaving the metal vulnerable. Engineers have developed coatings to protect aluminum in these applications, but many of these use potentially toxic chemicals. Previous research suggested that extracts of date palm leaves had an anti-corrosion effect. Gerengi decided to check date palm juice.
Gerengi noted that while an extract from date palm leaves is a known anticorrosive, this was the first test of the fruit’s juice. The juice, which he reported adsorbed into the aluminum’s surface, contains a number of sugars. Gerengi posited that these react with aluminum to form an anticorrosive film on the metal’s surface.
Husnu Gerengi (2012) Anticorrosive Properties of Date Palm (Phoenix dactylifera L.) Fruit Juice on 7075 Type Aluminum Alloy in 3.5% NaCl Solution. Husnu Gerengi Industrial & Engineering Chemistry Research doi: 10.1021/ie301771u