Hierarchical Membrane For Cleaning Up Oil Spills 32
rtoz (2530056) writes Whenever there is a major spill of oil into water, the two tend to mix into a suspension of tiny droplets, called an "emulsion." It is extremely hard to separate them, and they can cause severe damage to ecosystems. Now, MIT researchers have discovered a new, inexpensive way of getting the two fluids apart again. This new approach uses membranes with hierarchical pore structures. The membranes combine a very thin layer of nanopores with a thicker layer of micropores to limit the passage of unwanted material while providing strength sufficient to withstand high pressure and throughput.
Is this better for pour-over or French Press? (Score:5, Interesting)
Solomon performed experiments showing the effectiveness of the membranes in separating nanoemulsions while maintaining integrity at high pressure. The team used various techniques — including differential scanning calorimetry, dynamic light scattering, and microscopy — to test the separation efficiency, showing more than 99.9 percent separation. Microscopy images show the membrane in operation, with dye added to the water to make the droplets more obvious. Within seconds, an oil-water mixture that is heavily clouded becomes perfectly clear, as the water passes through the membrane, leaving pure oil behind. As shown in the microscope images, Solomon says, “We’re not only getting rid of the droplets you can see, but also smaller ones,” which contribute to the cloudy appearance.
How much oil (weight/weight) can a piece of membrane hold on to? Can the oil be stripped off of the membrane so that the membrane can be reused? If the answers are "less than 1:1" and "no", this might still be useful as a final purification stage after most of the oil has been removed or for situations where you are trying to clear smaller amounts of more toxic materials.