Figure 5-9. (A and B) Removal of the cross-linked hydrosilylated PB from the water surface. (C)
 The long cross-linked vacuum-dried fiber.

5.2.1.3 AFM imaging

 The evolution of the monolayer morphology during cross-linking was characterized by

AFM imaging of the LB films transferred onto mica substrates (Figure 5-10, Fr= 10 mN/m). As a

control experiment, it was first observed that under neutral pH conditions (pH = 7.0, no cross-

linking), the hydrosilylated PB forms a smooth and featureless monolayer (Figure 5-10B), in

opposition to the highly hydrophobic PB starting material which forms typical rubbery

continuous aggregates above the water surface (Figure 5-10A). After its hydrosilylation, the PB

becomes amphiphilic (hydrophobic backbone and hydrophilic triethoxysilane side groups) and

consequently surface active with the triethoxysilane pendant groups solvated into the water

subphase. This interfacial property of the hydrosilylated PB was also shown in the isotherms