Building cities with solar powered glow-in-the-dark cement
Mexican scientist José Carlos Rubio Avalos has invented a glow-in-the-dark cement (a key component of concrete) without electricity, that might one day beautify city nightscapes from Shanghai to Seoul.
The energy-efficient material soaks up sunlight during the daytime and begins to emit light as the sun sets.And it’s not just lampposts that the luminous invention could render obsolete.
“It could be used for exterior and interior applications,” says Rubio Avalos, a materials scientist at the Universidad Michoacana de San Nicolas de Hidalgo, Mexico.
Cement is a multi-billion-dollar industry — in 2014, global consumption of this material totaled 4.3 billion metric tons.
Now, Rubio Avalos’ invention has got the industry re-imagining how to use this material.
Coating houses, bike lanes, highways, interiors and even swimming pools with glow-in-the-dark cement are all applications for which Rubio Avalos has received requests, from governments, businesses and NGOs.
Rubio Avalos has patented his “novel cement matrix” — essentially, a modification of ordinary cement.
Rubio Avalos added photoactive materials to the cement to absorb and emit light, but the greatest challenge was to make the cement, an opaque material, soak up UV rays.
To do this, he had to alter its microstructure.
In the beginning of the concrete-making process, cement powder is mixed with water and the material starts to gel. The gel makes it form crystals.
“They look a little like cornflakes,” he says, and are an unnecessary byproduct.
In Rubio Avalos’ concrete, these crystals have been removed, which allows the sunlight to enter the cement matrix without being reflected.
The result: a material which absorbs UV rays during the day and releases light at night.
Its glow-in-the-dark properties will last “for at least 100 years,” he says, and adds that the technology works even on cloudy days.
It can work indoors, as long as the UV rays come in through the windows.
Marine blue and bright green are the colors currently available, but Rubio Avalos is working on cement that can glow white, red and purple.
He is currently building a pilot plant, which he expects will be ready to produce the material within three to five months.
Like any other innovation and owing to its structure ,glow-in-the-dark cement is around five times more costly to produce than ordinary cement.
“A one square meter piece, which is maybe 3mm thick, would cost around $60-70,” he says
But not only would the cement save power, but the process to create it is environmentally friendly as well. During manufacturing, the only thing released is water vapor.
There are a wide variety of commercial applications; according to Rubio, four billion tons of cement were created throughout the world in 2015, and the glowing cement can be used not only for streets but buildings as well.The technology could even be used in plaster.
According to the publication Investigacion y Desarrollo, Rubio’s research has reached the commercialization phase.
