Anyone know anythin...
 

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[Closed] Anyone know anything about "Waterlock" Superabsorbent, (Sodium polyacrylate)

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Apparently this is what they put in babies nappies to absorb any liquid.

According to Wiki it can absorb between 100 and 1000 times it's own weight in water.

Now someone has managed to drop a 40 container, with 20 tonnes of the stuff inside, into the sea.

So I'm guessing that the cargo will now weigh at least 20 tonnes x 100 = 2000 tonnes or possibly even 20 x 1000 = 20,000 tonnes! Those numbers don't seem real!

Any chemists on here who could shine some light on this?


 
Posted : 31/08/2019 8:42 pm
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Given the volume of a 40ft container is 67 cubic metres, and seawater has a density of 1025 kg/m3, it can only weigh ~68 metric tonnes at most...


 
Posted : 31/08/2019 8:47 pm
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Ever felt the weight of a pissy baby’s nappy? Weighs loads!

*No idea if your numbers are correct, but that’s going to be a big nappy.


 
Posted : 31/08/2019 8:48 pm
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Given the volume of a 40ft container is 67 cubic metres, and seawater has a density of 1025 kg/m3, it can only weigh ~68 metric tonnes at most…

That's what I don't understand?

How does it absorb 100 times it's weight in water? Does it expand? If it does then the container must of been destroyed and stuff scattered?


 
Posted : 31/08/2019 8:51 pm
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Google it, it expands massively.

If the container remains intact then only the outer material will absorb any water. IF the container breaks open it could. Reasonable chance the force of it expanding will break the container.


 
Posted : 31/08/2019 8:55 pm
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It expands. But I doubt with enough force to explode a shipping container.

And if it does, it just sit on the bottom of the oggin in a big gelatinous lump.


 
Posted : 31/08/2019 8:56 pm
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It doesn’t matter about the volume of the Waterlock, the specs given are based on its weight to absorbsion ratio.

20tonnes of Waterlock can absorb either 2000 or 20000 tonnes of water.

Big and light or small and heavy, if all of the Waterlock absorbs it’s capacity or water then it will heavy. It will also be big. Nappies swell when wet.


 
Posted : 31/08/2019 8:58 pm
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The result will be effectively equal in volume to the water it has absorbed.


 
Posted : 31/08/2019 9:57 pm
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Apparently salt (ie, sodium chloride) causes water to diffuse out of sodium polyacrylate, so sea water may not have the same effect as fresh water.

Time for an experiment with a packet of nappies, some empty baked bean tins, water and salt!


 
Posted : 31/08/2019 10:11 pm
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Sooooo all you number and science nerds..... How much sodium polyacrylate would it take to absorb the worlds oceans?

I'm thinking once gathered a ransom of up to 1 million dollars could be asked for not to go ahead with said fiendish scheme.

Asking for a friend obviously.


 
Posted : 31/08/2019 10:15 pm
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Any solutes in the water have a huge effect on the absorbent properties of the polymer.

I used to do experiments with my classes with it and we found that even really low salt concentration would affect the absorbency by at least an order of magnitude. There's enough polymer in the nappies we tested to absorb liters and liters of pure water, but they'll only hold about half a litre of urine* (Can't remember the nappy size or the actual volumes used).

*It was fake urine, but realistic enough to be very funny.


 
Posted : 31/08/2019 10:24 pm
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Curses. Foiled again..... I would of got away with it if it wasn't for the pesky salt.........


 
Posted : 31/08/2019 10:52 pm
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What happens if we put it on a conveyor belt, will it take off?

After googling a bit more, I think the polymer will absorb 67 tonnes of water, roughly, equal to the internal volume and the total weight will be the total of the tare, plus the original cargo weight, plus the absorbed water. So 67+20+4 = 91 tonnes in air. So roughly 3 times the original max gross weight.


 
Posted : 31/08/2019 11:07 pm

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