Look, No Moss!

• "When used on or in a concrete structure, photocatalysts decompose organic materials that foul the surface."


• "A hydrophilic surface prevents moisture from forming beads of water that may cause stains by attracting and holding dirt and then streaking the surface. Instead, moisture forms a thin film across a surface that interferes with the adhesion of dirt. Rain or simple rinsing can then easily remove the dirt. The result: your building or structure stays cleaner and more beautiful."
Source: Concrete Decor

Has this got you thinking yet? Got any ideas for structures whose chief selling points will be their ability to remain ever-so-sparkly-clean for the next millennium?

• The organic compounds affected by photocatalysts include dirt (soot, grime, oil and particulates) biological organisms (mold, algae, bacteria and allergens), air-borne pollutants (VOCs including formaldehyde and benzene; tobacco smoke; and the nitrous oxides (NOx) and sulfuric oxides (SOx) that are significant factors in smog), and even the chemicals that cause odors.¹
• In addition to decomposing the chemicals that contribute to air pollution, photocatalytic treatments are alleged to have other environmental benefits. Self-cleaning concrete will not require the use of the solvents now used to clean buildings, eliminating another source of pollutants.
• In one study, photocatalytic paving decomposed 15 percent of the nitrous oxide released by cars traveling the roadway and was more effective, in this regard, than planting trees on both sides of the roadway.

So, roadside 'planting' of the future will consist of concrete 'trees'. Perhaps we can have one of them in Moseley village, instead of a certain not-very-environmentally friendly steel planting. I'm not convinced that a concrete structure would look any better than steel, but if it helps keep the place clean, that's great! Furthermore, once the stuff is capable of sloughing off paint, certain people will be requesting that it be used for street furniture, house cladding and the sides of railway carriages.

• At the nano-scale, this new type of titanium undergoes a quantum transformation and becomes a semiconductor. Activated by the energy in light, the TiO2 creates a charge separation of electrons and electron holes. The electrons disperse on the surface of the photocatalyst and react with external substances, causing chemical reductions and oxidations and forming hydroxyl radicals that act as powerful oxidants to decompose organic compounds.

What's more, it can be programmed to light up, so any exterior wall can be turned into a giant light-emitting display. The sides of buildings will start to shine when someone walks past. Build a bit of phosphorescene into the concrete and watch it glow! Heck, I'd even change my mind about the Ent if it were made of glow-in-the-dark self-cleaning, air-freshening concrete!

Now, about the source of this information: Concrete Decor?
That title is a bit of a throwback, innit? Sounds very 50s/60s.
But on closer inspection, the content is good. I'm liking this more as I read.
Too bad I cannot get behind the subscription wall to see what this story says.
_{1. Does one get the impression that urine might be part of this list, and that self-cleaning walls might be a boon for certain nightlife hotspots?}