Mango leaf extract can stop ships from rusting

A team of Indian scientists has developed a compound from the leaf of the mango (Mangifera indica) tree that can protect ships from rusting and which is far more efficient than synthetic paints while also being non-toxic and environment-friendly.

Mango leaf extract can stop ships from rusting. Photo: Erik Mclean/Unsplash

According to Nishanth K. Gopalan, leader of the team from the National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, mango leaves were selected for their anti-oxidant properties and their abundant content of polyphenols, which are known to resist corrosion.

“Corrosion prevention was achieved through the formation of an insoluble organometallic complex at the metal-electrolyte interface,” says Gopalan, an author of the team report.

Gopalan tells that the compound, made by using epoxy as a base and incorporating mango leaf extracts in a substrate of amorphous silica, achieved 99 per cent inhibition of corrosion in commercial steel when immersed in a saline medium to mimic seawater.

He explains that ethanol was used to extract phytochemicals from dried mango leaves and various concentrations tested for maximum corrosion resistance. “The anti-corrosion property was owing to the creation of iron-polyphenol, an organometallic compound.”

Organometallic compounds are substances that have a metal bonding with at least one carbon atom of an organic molecule. They have such properties as insolubility, are of use in industrial chemical reactions as catalysts, and find use in the making of polymers and in the pharmaceutical industry.

Tests performed on the compound, using electrochemical impedance spectroscopy and surface analysis using X-ray photoelectron spectroscopy, confirmed the formation of positive bioactive elements.

Gosvami tells that much more work needs to be done to prove that the new method is superior to widely accepted methods of imparting corrosion resistance to steel such as galvanising with zinc or coating with conventionally used epoxy-based paints.

“What has been developed is a dip-coated method -- we do not know the strength of this coating and its ability to resist wear and tear in real conditions outside the laboratory, or the commercial viability of the product,” Gosvami says.

According to Gopalan, more rigorous tests are being planned. A number of synthetic corrosion inhibitors is available but most have the drawback that they are expensive, harmful to the environment and to human health which is why the focus on plant-based alternatives, he says.

The search for plant-derived phytochemicals that could prevent corrosion has led to such successful candidates as date palm seed extract and ginger root extract. Other examples include a hybrid of zinc and chicory (Cichorium intybus), extracts of seaweed (Gracilaria edulis) and horse mint (Mentha longifolia).

“The present work focused on corrosion inhibition on commercial steel in a marine environment and its application in coatings,” Gopalan says. (SciDev.Net)

YOU MAY ALSO LIKE

Researchers identify the maximum weight that children should carry in their school backpacks

Scientists from the University of Granada and Liverpool John Moores University (UK) have established that school children who use backpacks should avoid loads of more than 10% of their body weight—and those who use trolleys, 20% of their body weight.

Neanderthals used resin 'glue' for tools

Two caves -- the Grotta del Fossellone and Grotta di Sant'Agostino -- near the beaches of what is now Italy's west coast are producing some of the earliest evidence of ancient humans using adhesive on their stone tools, an important technological advance called "hafting."

Engineers create a simple test that can measure stress

Device measures hormones in sweat, blood, urine or saliva to determine stress.

Washable, wearable battery-like devices could be woven directly into clothes

Wearable electronic components incorporated directly into fabrics have been developed by researchers at the University of Cambridge. The devices could be used for flexible circuits, healthcare monitoring, energy conversion, and other applications.

Analysis of the Palaeolithic diet finds that, in the prehistoric age, for thousands of years there were no social divisions in food consumption

Scientists from the University of Granada have discovered that, although there were some variations in the eating habits of Megalithic communities over time, there were no significant social differences in the food types or the proportion of proteins consumed.

Creating Better Lithium-Ion Batteries Made Possible with New Discovery

New development has the potential to create a lithium-ion battery that can charge in a matter of minutes and improve high capacity battery performance for electric vehicles.