New "Hairy" Material Is Almost Perfectly Hydrophobic

drewsup writes "Wolfgang Sigmund, a professor of materials science and engineering at the University of Florida, has created a material modeled after spider hairs that acts as a nearly perfect water-repelling surface. Quoting Science Daily: 'A paper about the surface, which works equally well with hot or cold water, appears in this month's edition of the journal Langmuir. Spiders use their water-repelling hairs to stay dry or avoid drowning, with water spiders capturing air bubbles and toting them underwater to breathe. Potential applications for UF's ultra-water-repellent surfaces are many, Sigmund said. When water scampers off the surface, it picks up and carries dirt with it, in effect making the surface self-cleaning. As such, it is ideal for some food packaging, or windows, or solar cells that must stay clean to gather sunlight, he said. Boat designers might coat hulls with it, making boats faster and more efficient.' Hairy glass, anyone?"

Comments

Re:Gore-tex

[Hadlock]

I doubt this material "breathes" the same way gore-tex does. Enjoy your sweat bath! :)

Do boats go faster because it repels water?

[wisebabo]

Would there be a (very) thin layer of air between the boat and the water? Would there be a reduction in friction akin to the thin layer of water created when a skater's skates press down on the ice?

Or would boats go faster because no barnacles or mussels could become fastened on the hull of a boat? (I've heard that this used to be combatted with very toxic copper based compounds, no idea what they use now). If these microscopic hairs that were lifted from spiders work really well in preventing "fouling", why haven't whales evolved the same?

Just askin'.

Re:Do boats go faster because it repels water?

[osu-neko]

Indeed. It's worth nothing that, relatively speaking, whales are a fairly new evolutionary development. The first whales appear on the scene a mere 50 million years ago. The other question is one of competition. Some astoundingly suboptimal, inefficient designs have survived in nature for millions of years when they lacked significant competition or pressure in their niche. Whales don't seem to face a lot of competition or pressure, even less since we thinned their numbers in recent centuries.

Long story short, whales are unlikely to be anywhere near an optimal solution for their niche, and are unlikely to become one anytime soon.

Re:Do boats go faster because it repels water?

[MacOS_Rules]

Because just because you're ultra-hydrophobic, doesn't mean you're good at solving the problem of fouling.

The toxics are being phased out, but there's not much yet to replace them.
http://en.wikipedia.org/wiki/Biofouling is a very complex subject, with a lot of research dollars behind it these days.

The skinny of it is that many proteins will expose their hydrophobic cores and thus denature onto these ultra-hydrophobic surfaces; I'd imagine these surfaces to be excellent in pure water, and terrible in anything non-ideal (aka, the ocean).

Inside tire treads?

[caywen]

I'm sure the uses are limitless, but one thing I wonder is what would happen to a car's traction through puddles if you put this material in the treads of tires?

Re:Inside tire treads?

[mcgrew]

The hydrophobic material would be deposited inside the grooves, not where the rubber met the road.

Self Cleaning

[Anonymous Coward]

Sure it will be self cleaning for dirt, but I imagine that a something this hydrophobic is going to be a grease magnet. I can't wait to clean the chinese food off my spider coat.

Re:Self Cleaning

[Anonymous Coward]

At first I was going to make a snide comment along the lines of "ever heard of soap, aka a surfactant" but then I realized that if you can't really wet this substance, would it actually clean up with soap or not? I would guess yes, because the soap would still attach to the grease/oil but it may be a moot point anyway. Ever seen an oil soaked lotus leaf? That is a natural hydrophobic material, whose hydrophobic properties are also derived from its physical structure and not its chemistry. You also have to understand, this material isn't like a fur coat. It is 20 microns thick. Human hairs are 100 or so microns thick. Not long, thick.

Re:Hydrophopic

[telomerewhythere]

Actually note this from the article :

Although he hasn't published the research yet, Sigmund said a variation of the surface also repels oil, a first for the industry.

It also says that the Hydrophobic properties are based on physics alone and not chemistry. And ...

the UF surface may be the most or among the most water phobic. Close-up photographs of water droplets on dime-sized plastic squares show that the droplets maintain their spherical shape, whether standing still or moving. Droplets bulge down on most other surfaces, dragging a kind of tail as they move. Sigmund said his surface is the first to shuttle droplets with no tail.

I thought it is pretty cool stuff.

Battery/Fuel Cell Air Cathode?

[Black Gold Alchemist]

It seems like this would be good as a battery/fuel cell air cathode. You could put this stuff, then a layer of activated charcoal, then a current collector. This would cause the water-air interface to be somewhere inside the activated charcoal, so you would end up with a huge surface area of the air/water interface. This would improve alkaline fuel cells of all types (aluminium, iron, zinc and hydrogen).