Liquid Body Armor

[imnobodyx]

I came across a article my friend sent me about liquid body armor. It was essentially sheats of kevlar dipped in a Shear thickening fluid (or STF) which hardens almost instantly when force is is applied. Well i was interested in experimenting with this the STF is polyethylene glycol and silica nanoparticles the silica is supposed to be 500nm but I dont know what type or consitency the polyethylene glycol is supposed to be. I know Sigma aldrich has the silica but polyethylene i really am clueless about.

[Enthalpy]

Polyethylene glycol is an extremely common family (PEG, see Wiki) produced dirt-cheap from petroleum by-products. Easy to find in drum quantity. Many uses, including hydraulic oil, used for instance in brakes - then it's mixed with water and additives. Lab quantity at usual providers.

 

Molecular weight (=degree of polymerization) tells the viscosity, together with the amount of water, and the thing is hygroscopic. It behaves much like glycerine or glycol.

[chilled_fluorine]

I came across a article my friend sent me about liquid body armor. It was essentially sheats of kevlar dipped in a Shear thickening fluid (or STF) which hardens almost instantly when force is is applied. Well i was interested in experimenting with this the STF is polyethylene glycol and silica nanoparticles the silica is supposed to be 500nm but I dont know what type or consitency the polyethylene glycol is supposed to be. I know Sigma aldrich has the silica but polyethylene i really am clueless about.

 

I thought there were several types of PEG, could you try to get a little more specific? Do you want to know where to buy it, or what proportion to mix it in with the silica (or both)? I never knew Sigma Aldrich had nanopowders of anything, I'll have to check that out. If you want to know about the proportions, I'm completely clueless, sorry... This stuff sounds pretty interesting, do you know how much pressure has to be exerted on it to cause hardening? If you just want to play with the stuff, you could use the classic cornstarch and water mix, hardens almost exactly the way you described. Check google for more info, like mixing ratios, can't remember them at this time.

[sauroman1]

I came across a article my friend sent me about liquid body armor. It was essentially sheats of kevlar dipped in a Shear thickening fluid (or STF) which hardens almost instantly when force is is applied. Well i was interested in experimenting with this the STF is polyethylene glycol and silica nanoparticles the silica is supposed to be 500nm but I dont know what type or consitency the polyethylene glycol is supposed to be. I know Sigma aldrich has the silica but polyethylene i really am clueless about.

 

I did some research into STF and now want to make liquid armor also. Usualy 100-1000nm silicon dioxide particles are used mixed with liquid. I think liquid could be anykind even water (beach wet sand also has STF properties), just PEG is more stable liquid - it freezes at very low temperature and boils at high so does ethylenglycol based antifreeze.

It's hard to get nanosilica in my country but there are selled 10kg bags of fumed silica 3-4 micrometer size. I wonder if that would work also fine.

Material also could be used of many kinds. Kevlar is one of most strongest but there also strong fabrics such as nylon „Zylon“, „Condura“, „Dyneema“ and futuristic nanocellulose, graphene and GMO silk.

I saw one guy making stab proof t-shirt by sooking in STF: