preliminary investigation. Using PB, which pendant double bonds have been hydrosilylated with

trialkoxysilanes, as the cross-linkable block is a novel approach that can be applicable to a

variety of other polydiene-based block copolymers in order to retain a specific morphology at the

nanoscopic scale. The surface properties of the cross-linked monolayers were characterized by

surface pressure measurements such as surface pressure (7r)-mean molecular area (MMA)

isotherms at different reaction times, and isobaric experiments for various subphase pH values.

The morphologies of the Langmuir monolayers were studied by atomic force microscopy (AFM)

imaging of the corresponding Langmuir-Blodgett (LB) films.

 5.2 Results and Discussion

5.2.1 Hydrosilylated PB Homopolymer

5.2.1.1 Hydrosilylation reaction

 To demonstrate the viability of the 2D cross-linking method, we chose to first focus on a

commercially available linear PB homopolymer (Mn = 11,050 g/mol, ~ 204 butadiene repeat

units). Many publications and patents can be found in the literature on the hydrosilylation of

polymers.206-21 In mOst cases, the hydrosilylated polydienes were used as precursors to

synthesize macromolecular complex architectures such as arborescent graft polybutadienes,218

multigraft copolymers of PB and polystyrene,219 Or side-loop polybutadienes.220 Triethoxysilane

was used here as the pendant double bond hydrosilylating agent in stoichiometric amount with

the total molar amount of repeat units in the PB homopolymer and in the presence of Karstedt

catalyst (platinum catalyst) as shown in Figure 5-1. The reaction was carried out under argon for

24 h at 80 oC in dry toluene (water free environment). After workup, the hydrosilylated PB was

analyzed by 1H NMR and FTIR spectroscopies (Figures 5-2, 5-3, and 5-4).