PHYS01200704032 Debes Ray - Homi Bhabha National Institute

Chapter 2: Block Copolymer-mediated Synthesis of Gold Nanoparticles
amphiphilic copolymers self-associate in aqueous solutions to form supramolecular
aggregates consisting of hydrophobic domains surrounded by swollen hydrophilic blocks.
Hydrophobic interactions are a fundamental driving force in the assembly of amphiphilic
systems which helps in the macromolecular self-association and the formation of nanoscale
ordered structures through hydrophobic attraction [121]. The number of block copolymer
molecules forming one micelle is called the „aggregation number‟. The hydrophobic core can
serve as a „pool‟ for the incorporation of various hydrophobic compounds into the micelles.
As a result of the incorporation into the core water-insoluble compounds are transferred into
the micellar solution, a process called „solubilization‟. Depending on the length of the
hydrophilic and hydrophobic blocks as well as solution environments, the morphology of the
micelles can be spherical, cylindrical or lamellar [122]. Figure 2.5 illustrates different selfassembled
micellar structures formed by amphiphilic block copolymers with morphologies
like spherical, rod-like, vesicular and lamellar.
Figure 2.4. Schematic of self-assembled amphiphilic block copolymers into supramolecular
nanostructure (micelle) in solution.
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