The lag time of a barrier film can be dramatically increased by the addition of scavengers which consume solute before it crosses the barrier. This increase in lag time theoretically depends on the location of the scavenger within the membrane. In this paper, we construct layered reactive barrier membranes to test this theory. The experiments show good agreement with the theory, which predicts that the lag time increase can be doubled over that of a homogenous reactive barrier membrane by confining the scavenger to the downstream interface. Computer modeling also supports this claim, but suggests that this increase may come at the expense of increased solute leakage prior to the lag time. Reasons for this leakage are discussed, with recommendations for balancing lag time and leakage increases.
Bibliographical noteFunding Information:
E.E.N. is grateful for a National Science Foundation Graduate Research Fellowship. The research was chiefly supported by the Air Force Office of Scientific Research (grant F4960-01-1-0333) and by the U.S. Department of Energy (grant DE-FG07-02ER63509). Other support came from the Petroleum Research Fund (grant 39083-AC9) and from the National Science Foundation (grant CTS 0322882).
- Barrier film
- Lag time