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What is the long-term effects of storing materials in consumer electronics in a vacuum? Ie, plastics, electronic circuits and optical glasses?

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Hi Vincent and welcome to Physics Stack Exchange! I think there is a decent chance this question may be off topic here. But I will wait to see what the community thinks. –  David Z Dec 30 '11 at 7:39
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2 Answers

First time I lost a draft . Here it goes again:

Solids and liquids in vacuum will slowly erode due to sublimation. The molecules of the material have a kinetic energy distribution the tail of which has enough energy to propel the molecule into the vacuum . Long term the material will become eroded and if in a closed container the vacuum will also deteriorate and become a gas of the molecules that evaporated.

To get specific time values one has to know temperatures, magnitude of vacuum and materials.

Handwaving estimates: the time is very long: thermos flasks may be spoiled by breakage but I have not seen an eroded one, so glass is ok. The old kind of light bulbs could last for 30 years, their wire filaments OK. Also the space debris of last century are still there clogging the space ways.

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Is sublimation a real issue for covalently bonded polymer materials like plastics? Or for materials with extended electrons like metals? I would imagine sublimation takes forever, and the vapor pressure might be less than that for even a good vaccuum. Is there a time-scale? I am not sure if you are describing plastic or salt. Dry ice is only very loosely bound, because CO2 is so nonpolar and dissociates as a unit. –  Ron Maimon Dec 30 '11 at 11:31
    
In addition, "consumer electronics" presumably have solid-state logic. Isn't that going to fail due to diffusion (at nanometer scale) long before the sublimation will degrade critical components? (the latter would require at least tens of microns of material to sublimate) –  MSalters Dec 30 '11 at 12:18
    
@RonMaimon I am replying to the "long term effects of storing plastics etc in vacuum" question.From my handwaving estimates you see that I expect it to take very long. Certainly the energy distribution will have a tail no matter what material and some molecules will get off. Ice sublimates at the poles (or the noforst refrigerators), even though the temperature is very low. A vacuum will be worse. Higher temperatures will sublimate faster and the substance bonds will play a large role, but nothing is eternal.en.wikipedia.org/wiki/Sublimation_%28phase_transition%29 –  anna v Dec 30 '11 at 17:15
    
@MSalters well, the degradation you describe by diffusion will be similar to sublimation at the surface, again due to the tails of energy distributions. I suppose experiments are necessary to see what gets there first in nanometer scale circuits. –  anna v Dec 30 '11 at 17:18
    
Contaminants in air may be more destructive than sublimation in a vacuum. Just the water vapour in air could corrode the components. –  dotancohen Jan 29 '12 at 22:17
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Outgassing of solvents and oil/grease is probably more of an issue on realistic timescales than sublimation.

Some types of capacitors are notorious for failing in vacuum and anything with moving parts is going to need the grease replacing with some solid lubricant like Molybdenum disulfide or graphite.

If you need to operate the equipment the biggest issue is cooling. With no convection you need to actively cool electronics and often pot the entire circuit board in an epoxy.

Finally there is equipment that actually relies on air pressure. Hard disk drives use aerodynamics to float the heads above the disk and have problems above about 10,000ft

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