rationalized similarly as for Dend1, with the long PAA chains present in the corona, the dendrimer-like shape, and the large number of arms emanating from the central calix[8]arene core all heavily favoring the formation of highly curved interfaces. The images shown in Eigures 3-10b through 3-10j were recorded for surface pressures within the pseudoplateau and ranging from 4 to 8 mN/m. As the fi1ms are compressed, the PAA segments progressively dissolve in the aqueous subphase, underneath the PS cores of the surface micelles that aggregate into larger and thicker (~ 2 nm) domains. At the end of the pseudoplateau, in the region where the surface pressure sharply increases under high monolayer compression (7[= 8 mN/m, Figures 3-10k and 3-101), all the PAA chains have desorbed in the water subphase and stretch to form a brush underneath the aggregated PS cores. Contrary to the hydrophobic PtBA segments of Dend1 that collapsed above the A/W interface, the hydrophilic PAA segments of Dend2 anchored by the PS segments dissolve into the water subphase. Compression-expansion hysteresis experiments were also conducted within the pseudoplateau region (target pressure = 5 mN/m), and the results are presented in Figure 3-11. Very little hysteresis is observed with the pseudoplateau still present after numerous cycles, which means that the desorbed PAA segments can return to their original adsorbed state at low pressure after monolayer decompression. This was verified by transferring a LB fi1m at 2 mN/m during the second compression cycle, and AFM imaging revealed the presence of circular surface micelles with no aggregated domains. We do not have yet at this point enough experimental evidence to rationalize the small hysteresis shift, but it could for instance come from some entanglement of the PAA chains during the pancake-to-brush transition or from a different arrangement of the expanded PAA chains in terms of hydration and conformation compared to the one adopted after spreading and before the first compression.110