Influence of surfactant
Etching (progressing from left to right) in the presence of surfactant molecules. As soon as the molecules are able to penetrate into the etched channel, they form a protecting monolayer decreasing the radial etch attack. In this way nearly cylindrical channels are formed.
This work was stimulated by a collaboration between GSI Darmstadt and JINR Dubna (Russia), initiated by Christoph Schmelzer and Georgij Nikolaevich Flerov.