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Artificial superstrong silkworm silk surpasses natural spider silks

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41–50 of 69 posts

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#41
post #3

This is really neat. I hope they are secretly creating a hand-based slinger for this super strong spider silk.

I want to see a braided rope made with this stuff...

I want to see a space elevator. A guy can dream?

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#42
>Unlike silkworms, spiders cannot be farmed due to their territorial and aggressive nature.

They just need to breed friendly docile spiders.

https://www.getsurrey.co.uk/news/uk-world-news/royal-hollowa...

>Has a Royal Holloway researcher discovered the world's friendliest spider?

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#43
post #37
post #4

Tensile strength of 2 GPa for this silk compared to 0.4 to 0.8 GPa for steel. Really cool.. This is without including the strength to weight aspect!

I haven't found any info on the thickness of the material for those tensile strength measurements. How does it compare to something like Dyneema?

Apparently Dyneema has a tensile strength of 3.5Gpa

https://matweb.com/search/datasheet.aspx?matguid=4481722d60e...

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#44
2 GPa is 2GN/m^2, or 200kN/cm^2, which supports 20Mg. Taking silk density as 1 g/cm^3, that is 20M cm, or 200,000 m, or 20km.

Silk density is actually ~1.37 g/cm^3, so derate the above to 14.6 km. IOW, a silk cable can support 14.6 km of rope hanging below it.

Not close to strong enough for a Space Elevator.

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#45
post #10

Earlier quoted context omitted.

Could reinforced concrete be made with silk instead of steel?

The problem for such an application is not the strength, but the chemical stability in time. For it to be competitive, it would be necessary for the rate of hydrolysis of the protein fibers (which breaks the fibers) in an alkaline environment to be less than the rate at which rusting diminishes the strength of steel bars. This is very unlikely. At most there might be a chance for such fibers to be used for reinforcin…

These are of course, good points; cement probably being more porous than many people perceive. Just a little (hopefully interesting) speculation: adhesion might be less important, or entirely unnecessary if the reinforcing material isn't arranged like rebar. I.e. if it were just a tangle in the concrete.

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#46
post #10

Earlier quoted context omitted.

Could reinforced concrete be made with silk instead of steel?

The problem for such an application is not the strength, but the chemical stability in time. For it to be competitive, it would be necessary for the rate of hydrolysis of the protein fibers (which breaks the fibers) in an alkaline environment to be less than the rate at which rusting diminishes the strength of steel bars. This is very unlikely. At most there might be a chance for such fibers to be used for reinforcin…

Couldn't you coat the silk in some other material to get around that?

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#47
post #44

2 GPa is 2GN/m^2, or 200kN/cm^2, which supports 20Mg. Taking silk density as 1 g/cm^3, that is 20M cm, or 200,000 m, or 20km. Silk density is actually ~1.37 g/cm^3, so derate the above to 14.6 km. IOW, a silk cable can support 14.6 km of rope hanging below it. Not close to strong enough for a Space Elevator.

You lost a zero in there, so more like 146km.

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#48
post #47
post #44

2 GPa is 2GN/m^2, or 200kN/cm^2, which supports 20Mg. Taking silk density as 1 g/cm^3, that is 20M cm, or 200,000 m, or 20km. Silk density is actually ~1.37 g/cm^3, so derate the above to 14.6 km. IOW, a silk cable can support 14.6 km of rope hanging below it. Not close to strong enough for a Space Elevator.

You lost a zero in there, so more like 146km.

Examples here, one can sort by breaking length: https://en.wikipedia.org/wiki/Specific_strength

(2 GPa) / (1400 kg/m^3 x 10 m/s^2) = (2e9 N/m^2)/(1.4e4 N/m^3) = (2e5/1.4) m = 140 000 m = 140 km

P = F/A, F = M x g, M = A x L x rho

L = M/(A x rho) = (F/g)/(A x rho) = (F/A)/(g x rho) = P / (g x rho)

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#49
post #47
post #44

2 GPa is 2GN/m^2, or 200kN/cm^2, which supports 20Mg. Taking silk density as 1 g/cm^3, that is 20M cm, or 200,000 m, or 20km. Silk density is actually ~1.37 g/cm^3, so derate the above to 14.6 km. IOW, a silk cable can support 14.6 km of rope hanging below it. Not close to strong enough for a Space Elevator.

You lost a zero in there, so more like 146km.

Oops, tx. Seemed low.

Re: Artificial superstrong silkworm silk surpasses natural spider silks

#50
post #47
post #44

2 GPa is 2GN/m^2, or 200kN/cm^2, which supports 20Mg. Taking silk density as 1 g/cm^3, that is 20M cm, or 200,000 m, or 20km. Silk density is actually ~1.37 g/cm^3, so derate the above to 14.6 km. IOW, a silk cable can support 14.6 km of rope hanging below it. Not close to strong enough for a Space Elevator.

You lost a zero in there, so more like 146km.

Not enough for a space elevator on Earth, but definitely in the range you need for very long suspension bridges -- think in terms of railway bridges over the English Channel, the Straits of Gibraltar, the Irish Sea, and (with causeways/island hopping) the Bering Straits.
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