A topic of growing importance is the nano-structuring of inorganic materials by exploiting interactions with self assembling polymers. One example are multiphase polymers.
Driven by the mixing enthalpy, most polymers phase separate below their critical solution temperature. The components of block copolymers are covalently linked, restricting separation to microscopic length scales. Depending on composition, block copolymers form different equilibrium morphologies representing the energetically most favorable balance between- interfacial area and chain conformation.
Mass thickness contrast of polymers is often weak and conventional TEM can thus fail to characterize the morphology unless selective staining methods exist. This is the case for the poly(isoprene)-b-poly(ethyleneoxide) diblock copolymer system (PI-b-PEO) used as a structure directing agent and to provide solubility (see below). Fig. 1 shows the micro-domain morphology of PI-b-PEO where the rubbery phase is selectively stained with OsO4 .
Hybrid materials are obtained by addition of an inorganic precursor to a solution of PI-b-PEO in a "mutual" solvent.