A Controllable Nanometer-Sized Valve


  • We gratefully acknowledge support by the National Science Foundation Grant CTS 0340563. TJA also acknowledges support by the National Science Foundation REU Site Program in Functional Materials EEC 0243896. We also thank Drs. Ronald R. Chance, Harry W. Deckman, Tracy Q. Gardner, and Ben McCool for valuable discussions.


original image

The effect of a MFI membrane nanostructure change on n-hexane/ 2,2-dimethylbutane (DMB) permeation is described. The figure shows a) DMB transporting through the defects in an empty membrane, b) DMB permeation is blocked due to the initial defects closing by crystal expansion by n-hexane, c) both n-hexane and DMB permeation are blocked when the membrane is exposed to DMB first. The pores shrink and trap DMB so that almost all transport is blocked.