Archive for June 6, 2017

Solar paint offers endless energy from water vapor

Researchers have developed a solar paint that can absorb water vapour and split it to generate hydrogen — the cleanest source of energy.

The paint contains a newly developed compound that acts like silica gel, which is used in sachets to absorb moisture and keep food, medicines and electronics fresh and dry.

But unlike silica gel, the new material, synthetic molybdenum-sulphide, also acts as a semi-conductor and catalyses the splitting of water molecules into hydrogen and oxygen. Read more

Wood could clean up in the world of water purification

Oftentimes, the places that require water purification the most – such as developing nations or disaster sites – have the least in the way of infrastructure. This means that electrically-powered systems can’t be used, while technology utilizing materials such as silver may be too costly. Help could be on the way, however, in the form of water filters made from wood.

Developed by a team led by Prof. Monica Ek at Sweden’s KTH Royal Institute of Technology (where other interesting things have been done with wood), the filters more specifically incorporate wood-derived cellulose fibers.

These fibers not only trap suspended particles, but they’re also coated in a positively-charged polymer. Because bacteria and viruses are negatively-charged, they’re attracted to the polymer and then get stuck on it as the water is being filtered. They subsequently die while trapped there, unable to reproduce. Read more

Graphene membrane separates the salt from the seawater

Water may cover the majority of the planet’s surface, but thanks to a huge helping of salt, it’s hard to tap into as a source of drinking water. Once again, graphene could come to the rescue. Researchers at the University of Manchester have developed a graphene-oxide membrane with a scalable, uniform pore size that can filter out even the smallest salts, without affecting the flow of water too much.

Desalination plants already use a variety of techniques to produce safe drinking water, including shocking the salt and water into separating, using salt-attracting membranes, or harnessing the power of ocean waves to purify water and pump it back to shore. Graphene has already lent a hand before, too, acting like a big sponge that sits on the water’s surface, drawing water up through it and cleaning it in the process. Read more