They develop treatment with hydrophobic base coatings

International. A team of university scientists developed a new treatment that could help protect historic buildings built in limestone from erosion.

Working on the iconic York Cathedral, Dr Karen Wilson and Professor Adam Lee, from Cardiff's School of Chemistry, have developed a new treatment – using 'hydrophobic surface coatings' – that protects limestone from erosion generated by acid rain and air pollutants, while allowing the stone to 'breathe'.

Using a single layer of fatty acids combined with another fluorinated chemical compound, the Cardiff team, in collaboration with scientists at the University of Iowa and Diamond Light Source, created hydrophobic and superhydrophobic surface coatings for calcite (a common form of limestone) that delays the formation of harmful gypsum crusts by sulfur oxides. When applied to 19th century stone as in York Cathedral, the same coating repels the penetration of sulfuric acid.

"We hope that our work at York Cathedral will offer a new treatment to preserve limestone buildings that are already suffering the effects of erosion," said Dr Wilson.