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Picture Gallery

Close up of a spiral evolving on a nafion membrane. Ferroin is immobilised, with the other reagents flowing over the surfaces of the membrane.

Early on in the BZ reaction where Ferroin is immobilised on Nafion. A target is developing on the side facing the camera. The waves propagating on the reverse of the membrane are visible through the oxidised (blue) region.

Crossing wave pattern produced when waves have developed on both sides of the Nafion membrane.

Spatio-temporal chaos observed late on in the course of reaction, as the wavefronts become unstable and break up.

Computer enhanced image of the crossing wave pattern.


Ferroin catalyst immobilised in Nafion membrance. Reaction performed in a petri dish with only 1 face (top) of the membrane in contact with the remaining reactants solution. Early on in the reaction the fronts of the target pattern are far apart, but as reaction proceed they become closer and additional wave sources appear, producing a complicated pattern (right).

Sequence of images showing the propagation of BZ waves inside a length of dialysis tubing. These oxidation waves are travelling along a horizontal tube of diameter 8mm. Initially there is a mixture of Ferriin and Bromate inside the tubing and Malonic Acid outside. As the malonic acid diffuses into the tubing (and the bromate out) the solution inside exhibits phase and reaction - diffusion waves as shown.

BZ oxidation waves propagating down a vertical tube of dialysis membrane, otherwise conditions as above.


Reaction confined to a thin layer of ion exchange resin beads containing ferroin, fixed in a layer of silica gel. The whole gel is then bathed in the reamining BZ reagents. Early in the reaction (left) two separate spirals form, and then move together as reaction proceeds (right).

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