A liquid which absorbs EMF?

[Moreno]

What type of cheap and non-toxic liquid can efficiently absorb radio and microwaves? It could be a solution. So, for example, when you put a mobile phone into this liquid, it doesn't suppose to work (not because of a short circuit). 

[Bufofrog]

Water.

 

[swansont]

9 minutes ago, Moreno said:

What type of cheap and non-toxic liquid can efficiently absorb radio and microwaves? It could be a solution. So, for example, when you put a mobile phone into this liquid, it doesn't suppose to work (not because of a short circuit). 

It depends on the frequency range. An ionic solution will probably work pretty well for RF and microwaves, because it's a conductor  

For seawater, the skin depth (1/e attenuation) is less than 1 cm at 1.4 GHz, and decreases as frequency goes up (see table 1)

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2011JC007372

[studiot]

If you want a liquid to block off the mobile phone immerse it in mercury.

Note this liquid is toxic to humans but not mobile phones.

[Strange]

15 minutes ago, studiot said:

If you want a liquid to block off the mobile phone immerse it in mercury.

Note this liquid is toxic to humans but not mobile phones.

I know this suggestion is not completely serious but the former fire warden in me needs to point out that if the liquid made contact with the battery, it could cause heating (and toxic fumes) and possibly an explosion.

[John Cuthber]

1 hour ago, studiot said:

If you want a liquid to block off the mobile phone immerse it in mercury.

Note this liquid is toxic to humans but not mobile phones.

I suspect it is very toxic to mobile phones.

Mercury vapour will damage aluminium and solder.

[studiot]

My mobile has a plastic case, which is not wetted by mercury.

I think it sufficiently mercury liquid tight that the liquid would not enter the case.

How much mercury vapour is there in liquid mercury?

 

My answer is as serious as the question.

If the OP wants to shield a phone why not use an ordinary solid metal box of thick enough gauge?

There will be no mobile signal inside such a box.

Why put it into contact with a liquid?

 

Edited May 6, 2019 by studiot

[Strange]

6 minutes ago, studiot said:

My mobile has a plastic case, which is not wetted by mercury.

I think it sufficiently mercury liquid tight that the liquid would not enter the case.

Bt you are not the one who is planning to dunk their phone in liquid.

7 minutes ago, studiot said:

How much mercury vapour is there in liquid mercury?

I assume the answer to that is none, but the definition of "liquid" (ie. not being a vapour)

7 minutes ago, studiot said:

If the OP wants to shield a phone why not use an ordinary solid metal box of thick enough gauge?

Or just aluminium foil.

 

[studiot]

What would swansont's ionic solution do to the battery if you dunked the phone in?

 

Surely if you must surround it with a liquid, you would use the double case or double bag method which would protect the phone from  whatever liquid was used, whilst surrounding it with liquid?

 

Edited May 6, 2019 by studiot

[Moreno]

10 hours ago, swansont said:

It depends on the frequency range. An ionic solution will probably work pretty well for RF and microwaves, because it's a conductor  

For seawater, the skin depth (1/e attenuation) is less than 1 cm at 1.4 GHz, and decreases as frequency goes up (see table 1)

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2011JC007372

So, at what depth it will stop working completely?

[Strange]

15 minutes ago, studiot said:

What would swansont's ionic solution do to the battery if you dunked the phone in?

It would not provide a direct short across the battery. 

16 minutes ago, studiot said:

Surely if you must surround it with a liquid, you would use the double case or double bag method which would protect the phone from  whatever liquid was used, whilst surrounding it with liquid?

One would hope. 

[studiot]

4 minutes ago, Strange said:

It would not provide a direct short across the battery. 

How is that an answer to the question what would it do?

 

Personally, depending upon model since we are apparently talking about all mobile phones, I would be more worried about liquid ingress through charging or other jack type sockets, (Mini/micro usb types should be able to resist this) or the effect on microphone and/or speaker components.

 

[koti]

5 hours ago, studiot said:

Note this liquid is toxic to humans but not mobile phones.

Mercury fumes are toxic, you can submerge your arms into a bucket of mercury and you’ll be fine if you don’t do it for a prolonged time enough do your skin will start absorbing significant amounts of it...you should be much „finer” than a mobile phone submerged into a a bucket of mercury for a period of seconds which would surely short circuit it right away unless its completely water proof. Its the ingestion or inhaling of metals which is toxic, you have to get them inside your system somehow in fairly large quantities to be in trouble. If you have a good mask on you should be fine coming into short term contact with mercury, any piece of electronics exposed to a good electrical conductor like a metal while powered - I dont think so. Remember youre getting loads of stuff into your system every day through breathing if you live in the city and your body is capable of getting rid of most of it in a matter of days unless its a large concentration and it gets a chance to get into your bones where it stays.

Anyhow, a powered, non hermetic mobile phone would be much more in trouble having a bath in mercury than a healthy human who does not ingest/breathe in the metal.

Edited May 7, 2019 by koti

[swansont]

12 hours ago, studiot said:

What would swansont's ionic solution do to the battery if you dunked the phone in?

 

You would need to seal the phone in something, if it were not waterproof

12 hours ago, Moreno said:

So, at what depth it will stop working completely?

That depends on what level of signal is required for it to work, and how strong the source is. Signal attenuation is exponential, so it will never go to zero. But at some point you can't discern it from the noise.

[koti]

23 hours ago, Moreno said:

What type of cheap and non-toxic liquid can efficiently absorb radio and microwaves? It could be a solution. So, for example, when you put a mobile phone into this liquid, it doesn't suppose to work (not because of a short circuit). 

Why does it have to be a liquid? A thick lead box would do the job. 

[CharonY]

!

Moderator Note

Considering the narrow scope of the question provided by OP, it would be great to stay on-topic (though asking for clarification is fine, just try not to stray too far off). Thanks.  

 

[John Cuthber]

Not strictly a liquid but you can pour it...

metal shot would also act as screening.

I can't think of a solution involving any liquid that doesn't include sealing the phone in a bag or something (unless you don't care about ruining it).

If you are going to seal the phone in  a bag anyway, you might as well wrap it in foil.

[Moreno]

Is it possible to create some coktail of nanoparticles which absorb all the radiation between 300 MHz and 3GHz? And convert this radiation into heat?