# Volkswagen's invisible silver



## Topher_osAUrus (Jan 26, 2017)

According to this link

http://gizmodo.com/volkswagen-put-an-invisible-layer-of-silver-in-its-new-1791624687

Volkswagen has an additional add on, of course, that is a windshield with an invisible layer of silver, as the heat conductor to melt snow and ice off the windshield.

I know gold can be pounded ridiculously thin. But, silver? Thats probably not how they are doing it.. But.... How?

Having it actually a chemical portion of the glass itself? The article speaks of filaments at the bottom by the wipers, so they don't have ice stick to them. I wonder..


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## Lou (Jan 27, 2017)

It wouldn't be the first tall tale told by them.


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## nickvc (Jan 27, 2017)

Many years ago one of my best customers for silver scrap was a large double glazing company. They used targets to I think sputter a very fine layer of silver onto their glass, it was invisible,as it helped to keep cold out and heat in.


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## rickbb (Jan 27, 2017)

I would think they use an electro-chemical method to bond the silver layer to the glass. Vapor deposition would be an easy way to get a very thin layer but would not be bonded and could be easily wiped off. It would have to have some kind of top coat to protect it from wear.

Unless the glass is in layers and the silver is deposited inside the sandwich.


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## Topher_osAUrus (Jan 27, 2017)

I sadly could not sleep last night, as my mind was wandering ...thinking of stupid Volkswagen, and their dumb invisible silver..

It made me wonder if, a colloidal silver could be made into the glass, and if that could still have the ability to let electricity pass through it?

I doubt it, very much.

Arent the eyeglass lenses that adjust to bright sunlight made with silver? ...I doubt anyone would want that as a function on a cars windshield, it may end up killing people.

Nick, that surely must be the process they are using.


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## 4metals (Jan 27, 2017)

I have a greenhouse for my hydroponics and the glass I chose was specifically not the glass designed with the silver layer. The silver layer is sputtered on the glass and then it is sandwiched with another sheet. The layer of silver apparently prevents light of a certain wavelength from passing through the glass thereby eliminating the solar gain or warming of the greenhouse. This is effective keeping the glass solariums cooler in the summer sun. 

I wanted maximum heat penetration so I can rely on passive solar heat gain in winter. The trade off is I have to deal with shedding a lot of heat in summer. Everything in life involves a trade off!

But from a refining perspective, if the silver is actually there, as Lou said it wouldn't be Volkswagen's first tall tale, recovery would entail crushing to powder and leaching and the actual concentration of silver in ounces per pound of refinable product would be so low that it would be uneconomical.


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## Topher_osAUrus (Jan 27, 2017)

4metals said:


> ...Everything in life involves a trade off!...


Yeah, the words of the famous philosopher ring true, yet again



4metals said:


> ...you don't always get what you want but sometimes you get what you need



I figured the chances of reclamation from the glass would be very unprofitable. It would probably just end up in the "tin bin" with a lot of other trace pm's in cars that don't get salvaged before they get shredded. 

I like silver, quite a bit.. The chemistry of it is incredible, and has granted humanity a great many things... Well beyond it just being a shiny, aesthetically pleasing metal. Heck, the chemistry of photography alone in amazing. 

I could see the benefit of having a layer on the glass so it doesn't allow heat from the sun in.. Leather seats are the *worst* in the summertime..


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## rickbb (Jan 27, 2017)

4metals said:


> recovery would entail crushing to powder and leaching and the actual concentration of silver in ounces per pound of refinable product would be so low that it would be uneconomical.



You got that right. I tried to recover silver from old plasma TV's and that silver was visible to the naked eye. No way to make money unless you have tons to process. Even then I bet it's barely a profit.


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## Lou (Jan 27, 2017)

It can be applied via PVD like Nick mentioned, but how would such a thin layer, a few tens of thousands of atoms thick, move enough heat??


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## Topher_osAUrus (Jan 28, 2017)

Thats the multi-milliom dollar question Lou.

Needless to say, I'm rather interested to see what details they end up giving about it. Assuming it is really even happening, or a gimmick.


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## g_axelsson (Jan 28, 2017)

Topher_osAUrus said:


> It made me wonder if, a colloidal silver could be made into the glass, and if that could still have the ability to let electricity pass through it?


Short answer, not without loosing transparency.

Slightly longer, to conduct current the atoms must be in very close proximity and form conductive paths, so my guess is at least 10-20%, if not more, has to be metallic silver to conduct electricity. Compare to conductive paint or glue which uses fine silver or carbon particles, screen printed conductors on mylars are another example. If it was possible to use less silver they would do it.

Göran


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## Topher_osAUrus (Jan 28, 2017)

And surely if there was that much colloidal silver in the glass, there would be a LOT of issues with transparency... I'm getting curious and curiouser..


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## rickbb (Feb 9, 2017)

Saw a different article that had more details, they are doing vapor deposition and sandwiching it inside the glass layers.

But still will it generate that much heat.


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## Iggy-poo (Feb 9, 2017)

When I was in the Navy, long ago, the windows on the gun mounts were sandwiched Tin Oxide, which would generate the heat to defrost, even in Arctic Weather. It was just like a transparent heating plate.


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## mls26cwru (Feb 10, 2017)

Lou said:


> It can be applied via PVD like Nick mentioned, but how would such a thin layer, a few tens of thousands of atoms thick, move enough heat??




My company does something similar with a chemical vapor depositions (pvd, pecvd, ion assist cvd)... one of our coating lines uses Indium-Tin-Oxide (ITO) and is on the order of a few thousand angstroms think. Depending on the deposition parameters, the clarity and resistivity can be altered to given specifications. In the past we have designed clear heated anti-ballistic windows for navy ships. (The ballistic requirements stated that the window had to withstand 3 impacts from a 50 caliber hitting in the same spot without complete penetration... roll that one around for a second!)

My assumption is that the coating in question is a silver containing compound of some sorts... most of these thin film coating companies will give names to their coatings so they aren't giving away proprietary information. They will call it something like "TitanCoat5" instead of "Titanium Nitride Diamond-like Carbon coating #5"


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## snoman701 (Feb 10, 2017)

Likely rf hearing of water molecule itself. I'll add more later.

Ok, NOT rf heating from what I could tell...which is good. I was scared of that thing. Always felt like it was sterilizing me. Plus the interference would have been ugly. 

Back in the day I worked in this field.

The grid on your standard car rear window defroster is silver that is screen printed on flat glass. The frit, once heated, bonds directly to the glass, then the glass is slumped over a mold....wallah, a heating element.

This is very likely the same technology that is being used near the wipers. 

On the rest of it, could be a couple of things...

They could be changing the surface energy of the glass. Breaking the bond between the ice and the glass, actually repelling the ice on a microscopic level. At that point, all the wipers have to do is push it away. 

I have trouble believing that that would take 500 watts though...that's a huge amount of electricity in a car. My guess is that it's a uniform film that is sputtered on, with a conductive bus at either end. Essentially making the windshield one giant heating element. By varying the thickness of the sputter, they could effectively choose which part of the window to melt first.


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