Spray-On Liquid Glass

bLanark writes with news of a new substance that can be sprayed on for a durable, easy-to-clean film on almost any substance, hard or soft. The liquid glass is essentially pure silicon dioxide, and it goes on in a layer 15 to 30 atoms thick. It is breathable and flexible, but waterproof and resistant to bacterial growth. The patent is held by a German company, Nanopool, which is in discussion with many parties about a wide range of uses: keeping public spaces sanitary, keeping restaurants clean, and keeping cars or trains clean. "The spray forms a water-resistant layer, meaning it can be cleaned using only water. Trials by food-processing companies showed that sterile surfaces covered with a film of liquid glass were equally clean after a rinse with hot water as after their usual treatment with strong bleach."

Comments

Re:All glass is liquid

[nomadic]

Urban legend. Glass is an amorphous solid.

Re:winshield repair?

[Chyeld]

Commando baby, it's the only way.

Re:All glass is liquid

[EvanED]

Wikipedia disagrees.

In particular, the myth that glass in older houses is thicker at the bottom because it flowed definitely seems to be just that -- a myth:

If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more but this is not observed. Similarly, prehistoric obsidian blades should have lost their edge; this is not observed either (although obsidian may have a different viscosity from window glass). ... If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then the effect should be noticeable in antique telescopes. Any slight deformation in the antique telescopic lenses would lead to a dramatic decrease in optical performance, a phenomenon that is not observed.

But will it get you high when you snort it?

[Orga]

Inhaling finely divided crystalline silica dust in very small quantities (OSHA allows 0.1 mg/m3) over time can lead to silicosis, bronchitis or (much more rarely) cancer, as the dust becomes lodged in the lungs and continuously irritates them, reducing lung capacities (silica does not dissolve over time). http://en.wikipedia.org/wiki/Silicon_dioxide

Re:But will it get you high when you snort it?

[penguinchris]

Not that this is really relevant (your point stands), but you've got some geological details wrong (IAAG).

Most mountains have a lot of granite, yes, so I'll start with that - first, your assertion that granite is harder than glass is perhaps technically true, but there are several things to consider. Granite is composed primarily of quartz (hardness 7) and feldspar (hardness 6) while plate glass is traditionally considered to be hardness 5.5. Fine. But - glass is structurally solid and homogeneous, while granite is composed of a bunch of different mineral crystals stuck together, some of which (like biotite) might be considerably softer. This heterogeneity likely weakens the overall structure of granite (though this is far outside my areas of expertise within geology and material science).

Most erosion in mountains comes from water, not wind. Wind is significant but only in certain areas in certain types of rock - think Arches National Park in Utah, with those wind-blown formations in sandstone, a very weak rock. For water to do anything, you need either something that will react chemically (which pure silicon shouldn't as far as I know) or you need mechanical action. This can be freezing and thawing like what cracks the roadway, or water carrying particulate over the surface (like in a stream). Again, with such a smooth, homogeneous surface, I don't see this being a problem... you don't really see erosion on glass windows, for example, even sloped ones.

Erosion over hard surfaces (such as granite) is a big part of my research. It is extremely slow. How much erosion happens to rock counter tops, for example? Not all of those are granite, by the way, though they may be called that at home depot - there's a very wide range of minerals that goes into counter tops, many of which are soft enough to be eroded quite easily.

And anyway - the "particulate" you mentioned as eroding mountains is particles of rock and mineral. Hard stuff. Unless you cook with sand, I really don't see this being a problem.

What I'd be worried about is what happens in an impact. If you drop something heavy and sharp-edged on it, is it going to break? Even small breaks give you the opportunity for erosion as discussed. If this stuff fractures easily, then my points are partially invalid. It doesn't seem like that's the case, though. Seems like pretty great stuff.

Re:winshield repair?

[smellsofbikes]

Can I now avoid costly windshield replacements by simply spraying this stuff on my windshield after a ding storm, or crack?

The problem with having a crack isn't the divot where the crack started, it's the leading end of the crack. When you apply stress to a material that has a crack, the force per unit area at the tip of the crack approaches infinity, so what you have to do to keep the crack from spreading is increase its area. That's why windshield repair people drill holes at the ends of the cracks and then fill them.

Even if your intent is just to fill the much smaller divots in the glass, 30 molecules thick isn't going to make much difference. What you need is a material that has roughly the same index of refraction as the glass, that you can spread over the divots like makeup.

Re:Meh

[Jane Q. Public]

Part of the reason for this is that water tends to act almost like a "catalyst", encouraging cracks in glass to spread much more rapidly. According to an article in Scientific American, water causes glass to crack more easily because when a water molecule enters the crack, a reaction occurs in which a silicon-oxygen bond at the crack and an oxygen-hydrogen bond in the water are cleaved, creating two hydroxyl groups attached to silicon. As a result, the length of the crack grows by the size of one bond rupture. The water reaction reduces the energy necessary to break the silicon-oxygen bonds, thus the crack grows faster.

Theoretically, any strong material that will fill the crack and prevent moisture from entering should stop the cracking process. I don't see why a film of silicon dioxide would not work as well as resin.

Re:bleach is great but focus on antibiotics

[ceoyoyo]

Bleach is the nuke that people who are serious about killing bacteria use to clean their counters with. Antibacterial cleaners are the things the amateurs at home use.

If you can satisfy the pros that they don't need to use bleach on their counters then the only remaining reason for anyone to use an antibacterial cleaner on his counter at home is superstition.

Re:winshield repair?

[Turken]

Actually, "play sand" is still almost entirely silicon dioxide, just like "regular sand."

The only difference is that the play sand has been washed and screened so that it has less dust and a more uniform grain size. The fact is, "toxic" silicon dioxide is all around us, and we all breathe some amount of it in every single day. Silicosis only becomes an issue for people that breathe in large amounts of it on a regular basis - i.e. people who work 40+ hours a week in fine-dust-generating industries. If the silicon dioxide found in "regular sand" was truly a health hazard, then every beach in California would be outlawed (or at least coated in warning stickers) telling you to keep away. Hasn't ever happened, and never will, since casual exposure from playing in sand is not a silicosis hazard in any way.

Another thing to consider is that given the typical chemical makeup of rocks and sand is that if it were even possible to remove all the "harmful" SiO2 from sand all you'd be left with was a fine dust of metals and trace elements which would be harmful if played in.