FIGURE 8.

Relaxation of PPL monolayers after sequential compressions. After spreading on a captive bubble, monolayers of PPL were compressed initially at ∼2 Ų/(molecule × min) to 45 mN/m and then more rapidly to 52 mN/m. Interfacial area was then held constant, while π relaxed. After achieving a π that remained constant for 30 min, the compression and relaxation were repeated, with time recorded for each cycle relative to the moment at which relaxation began. Data are representative of three experiments.