Generales

By: Yenifer Aristizábal Grajales - Journalist

Researchers from Universidad de Antioquia and the university Antonio Nariño developed a luminescent coating for roads. It takes advantage of sunlight and is made from recycled styrofoam.

The material expanded polystyrene or styrofoam is 0 % biodegradable, that is, it is not decomposed by the environment. Photo courtesy: Gutierrez, E. I., & Colorado, H. A. (2020).

Expanded polystyrene or styrofoam is used in everyday life: in a takeout lunch, school homework or a cup of coffee. Its widespread use has led to initiatives that promote its prohibition because it is a complex element to recycle.

"It is very bulky and not very tough. That’s why we have focused on a line in which we work with materials that have these big problems to be reused", said Henry Alonso Colorado Lopera, coordinator of Grupo CCComposites Group —Cement, Ceramics and Composition— which belongs to Universidad de Antioquia’s Faculty of Engineering.

The professor works in recycling and construction materials. Along with researcher Elkin Iván Gutiérrez Velásquez, a member of CCComposites, they developed a multifunctional material that contributes to the solution of an environmental problem. Moreover, it has an important function: to improve road lighting by taking advantage of solar and natural light sources.

Colorado Lopera explained that this material has been undervalued in the recycling market. Due to its bulky nature, it represents a problem not only because it is difficult to reuse, but also because it occupies large spaces in landfills. "We know that these materials have a very short useful life, and this is a problem in Colombia and many other countries", he said.

This development, on which they have been working for nearly two years, has is closely related to the saving of electricity. Fluorescent materials used on asphalt or concrete absorb natural or vehicle light for a short time. The light is emitted without the need for external electricity.

This is a type of transparent "paint" that consists of a polymeric-based material. This material acts as a matrix and is made from the dissolution of expanded polystyrene mixed with ceramic particles. Such particles give it the property of luminescence. The material is applied on the road as if it were paint. Signaling lines are made or painted over the existing ones, and when a car drives with its lights on, this external light illuminates the material, which absorbs the light energy and returns it. Thus, the phenomenon of luminescence is produced.

Professor Elkin Gutiérrez pointed out that this coating glows at night and is invisible during the day. Strontium aluminate particles were used in the coating, and the greater the number of particles, the greater the incandescence, and the more visible it is. "The greater the number of particles, the greater the emission they will generate. However, a very high number of particles would considerably affect the final cost of the product. We found that a small number is enough", said the researcher.

The development of the material and technology for implementation on a road is the first phase of the project. At a later stage, they will seek to work with a company from the construction industry to conduct field evaluations.

For the researchers, secondary roads —and even paved tertiary roads— are poorly lit because of little traffic, especially in Latin American and African countries. "Much of the world has roads with very poor lighting, some of which have little traffic. This is where our proposal is perfectly applicable. Besides, it is a material that contributes to sustainability through better solid waste management and reduces light pollution by reducing light sources on the road", concluded Henry Colorado Lopera.