© D. Cot/CNRS Photothèque
The bright colors might evoke a candy-filled garden, but the digital coloring and extreme magnification of the image (x 10,000) are deceiving. The “grass” is actually the internal surface of an alumina tube on which research scientists have placed a mixture of silica and copper to create a membrane. Depending on its porosity (i.e., the gap between each grain of material), it can act as either a filter to separate liquid from gas, or as a catalyst to trigger a chemical reaction when the membrane is crossed. Unfortunately, instead of producing a continuous and consistent layer, the two materials generated undesirable “pink marbles” of silica and “blue marshmallows” of copper oxide crystals spaced very far apart. But not to worry, this shortcoming will not prevent these nanopore engineers from continuing their experiments.
Eric Prouzet, Institut européen des membranes (European Membrane Institute), Montpellier.