New article: Researchers segregate Liquids Using Visible Light read more at here http://www.spinonews.com/index.php/science/item/3357-researchers-segregate-liquids-using-visible-light

The researchers ultimately want to separate the oil substances from water, like water covered with a mass of bubble and saltiness of the water retrieved from the crude oil wells.

Researchers found that using photo responsive surfaces to the water can be separated by light. They have also used electrostatic methods but failed due to low intensity and high saline in water. The photo responsive surface interact with the water and the phenomenon is called as Wettability. The process Wettability can be activated with light. Researches thought they could separate water from oil by the droplets of water come together to become whole and spread across the surface. The more water droplet combine together and the more separate from oil. Photo responsive screen material made up of (TiO2) titanium dioxide.

[Hydroelectric Dam that Slows down the Rotation of the Earth]

Team has found out the that titanium dioxide surface to make it responsive to visible light. They did so by first using a layer-by-layer deposition technique to build up a film of polymer-bound titanium dioxide particles on a layer of glass. Then the team dip-coated the material with a simple organic dye. The resulting surface turned out to be highly responsive to visible light, producing a change in wettability when exposed to sunlight that is much greater than that of the titanium dioxide itself. When activated by sunlight, the material proved very effective at demulsifying the oil-water mixture getting the water and oil to separate from each other.

 “This creates an electric potential difference to be established between the surface and the liquid upon illumination, and leads to a change in the wetting properties.” Dr.Varanasi. By selectively changing the material’s wettability using a moving beam of light, a droplet can be directed toward the more wettable area, pushing forward it in any desired direction with great accuracy. Such systems could be designed to make microfluidic devices without built-in boundaries or structures.

[Now Wi-Fi routers in home can detect members among family]

The switchable wettability of these surfaces has another benefit they can be largely self-cleaning. When the surface is switched from water-attracting to water-repelling, any water on the surface gets driven off, carrying with it any contaminants that may have built up.