Hierarchical assembly of nanostructured hybrid films

The successful approach to smart responsive particles was further transformed into the principle of hierarchical self-assembly in the system when the particle 

10 Schematic representation of grafting silica nanoparticles with tri-block copolymer brushes to the Si-wafer surface (a) a layer of the nanoparticles on Si-wafer (b). 

Solvent Contact angle(°) Nitrogen, at. % (XPS, 30° angle of Incidence) 

The cooperative character of the conformational transitions in the densely packed monolayer of smart particles makes up the second level of response (Fig. 18.11). The combination of the smart particles in one layer introduces new kinds of morphology. The core-shell transitions of unimers are transformed into transitions between different phase-segregated morphologies in the grafted monolayer in selective solvents. Clusters of the unfavored polymer are embedded in the layer of extended chains (matrix) of the favored polymer. In other words, the core-shell transitions of unimers are transformed into the interplay between lateral and layered phase segregation. The increase in 

7 7 Schematic representation of the switching behavior of the P2VP7-PS7 star-copoiymer iayer chemicaiiy grafted to the surface upon exposure to soivents (a) seiective for P2VP (dashed iines) (b) nonseiective and (c) seiective for PS (soiid iines). Reprinted with permission from Ref. 44. Copyright 2005 American Chemicai Society. 

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