Crispy noodles are the missing link between today's carbon-emitting cars and tomorrow's clean hydrogen cars. It turns out that the structure of crispy noodles — rigid, twisty, and porous — perfectly matches that of a new polymer developed to trap and reuse hydrogen atoms in new "green" cars. University of Manchester researcher Peter Budd helped develop the polymer, which he calls a 'polymer of intrinsic microporosity,' or PIM. And he explains it entirely in terms of noodles.
The PIMs act a bit like a sponge when hydrogen is around. It's made up of long molecules that can trap hydrogen between them, providing a way of supplying hydrogen on demand.
Imagine a plate of spaghetti - when it's all coiled together there's not much space between the strands. Now imagine a plate of crispy noodles - their rigid twisted shape means there are lots of holes. The polymer is designed to have a rigid backbone, and it has twists and bends built into it. Because of this, lots of gaps and holes are created between molecules - perfect for tucking the hydrogen into.
The holes between the molecules give the polymer a very high surface area - each gram has a surface area equivalent to around three tennis courts. The molecules in the polymer act like sieves, catching smaller molecules like hydrogen in the gaps between them. The holes created in the polymer between molecules are a good fit for hydrogen. Hydrogen molecules stick in these holes and are kept there by weak forces - this means they can be released when they are needed.
Hydrogen is most sticky when it is cooled down to low temperatures. When the hydrogen is needed to power the car, the system would just raise the temperature to free up the hydrogen molecules.