FIGURE 5.

Effect of addition of oxidized PL to BLES, surface area reduction. The bar graph depicts the percentage of surface area compression required for the films to attain a minimum surface tension near 0 from 20 mN/m during the 21st dynamic cycling. Samples are the same as in Fig. 3. Extrapolated compressions of >100% were estimated for those films that could not attain low minima during compression. Comparisons among the samples were conducted using Tukey's studentized range (highly significant difference) test. Letters A–D represent comparisons among samples within a cycle. Means with the same letter are not significantly different for p < 0.05.