Franz Geiger
Harold Henderson: Why “surface science”?
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FG: We start out with the most abundant mineral, silica, found in sand. We set up an interface where water meets the silica. That’s a platform we can control and make more complex, one step at a time. Instead of starting with a real soil, which has who knows how many different things in it and is hard to generalize from, we start with a simplified soil and see how each new addition affects it.
FG: Actually, we see chromium in three different forms. Its toxicity changes completely depending on its oxidation state. Metallic chromium, or chromium 0, doesn’t corrode, doesn’t react. Chromium 3 is an essential nutrient that helps you digest sugars. Without it you die. Chromium 6, or chromate, originates mainly from fossil-fuel combustion. It’s also used in the metal, alloy, and wood industries and in petrochemical cooling towers.
HH: So you aim to be more realistic.
FG: We work with a quartz hemisphere about one inch in diameter. Quartz is ultrapure silica, containing only silicon and oxygen atoms.
HH: How much does all this cost?
