This Crazy New Material Switches From Super Hydrophobic to Super Hydrophilic in an Instant

Scientists have created a material that can switch between repelling and absorbing water droplets at the flick of a switch.

The copper based material can go from super hydrophobic (water hating) to super hydrophilic (water loving) in a matter of seconds and could be used for water filtration, biomedical devices, liquid lenses and smart self-cleaning surfaces.

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from the article

This new study creates a material that can switch properties in seconds – instead of hours – and it’ll surprise you with how simple it turned out to be.

The scientists used a copper based surface which changes from water loving to water hating by simply changing the voltage applied across the surface. The voltage required to change the properties of the surface is as low as 1.5 volts – lower than that found in a normal household battery.

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its that simple

changing the voltage

Had a quick look at the superhydrophobic coatings.

Two questions:

• do garments coated with such stuff get dirty?

• if they do, how can you clean them?

Had a quick look at the superhydrophobic coatings.

Two questions:

• do garments coated with such stuff get dirty?

• if they do, how can you clean them?

mcgoon said:

Had a quick look at the superhydrophobic coatings.

Two questions:

• do garments coated with such stuff get dirty?

• if they do, how can you clean them?
  

Disconnect the battery?

Tau.Neutrino said:

This Crazy New Material Switches From Super Hydrophobic to Super Hydrophilic in an Instant

Scientists have created a material that can switch between repelling and absorbing water droplets at the flick of a switch.

The copper based material can go from super hydrophobic (water hating) to super hydrophilic (water loving) in a matter of seconds and could be used for water filtration, biomedical devices, liquid lenses and smart self-cleaning surfaces.

more…

I’ve been doing work on corrosion. I’ve observed that all metal surfaces transition from hydrophobic to hydrophilic over time. The same may be true of glasses.

What happens with metal is that a pure metal surface is hydrophobic, but the interaction of oxygen in the air and small electric currents from corrosion fairly rapidly makes the surface hydrophilic.

In normal circumstances, a hydrophobic drop contact angle exceeding 90 degrees, from memory about 110 degrees, transitions over a period of about a fortnight to a hydrophilic drop contact angle of about 1 degree. My colleagues at CSIRO observed this on aluminium, steel and zinc.

What is much more difficult would be to do the process in reverse, from hydrophilic to hydrophobic.

mcgoon said:

Had a quick look at the superhydrophobic coatings.

Two questions:

• do garments coated with such stuff get dirty?

• if they do, how can you clean them?
  

Quick answer, yes, soap or other surfactant changes the surface tension.

Detergents such as soap typically contain a water loving and water hating end. The water hating end attaches to the water repellant garment and the water loving end brings the water close enough to dissolve the grime.

That’s why we use detergent.

mollwollfumble said:

Detergents such as soap typically contain a water loving and water hating end. The water hating end attaches to the water repellant garment and the water loving end brings the water close enough to dissolve the grime.

That’s why we use detergent.

If i’d switched on my brain when i got up, i’d have remembered that.

Thanks.