Hybrid inorganic-organic polymer phases

Polymer materials are ubiquitous in our daily life. They often consist of more than one species of polymers and, therefore, can be called multicomponent systems, for example, polymer blends and block copolymers. Because of the repulsive interaction between the constituent polymers, multicomponent polymer materials often show phase separation. Organic-inorganic composites are another class of polymer-based multicomponent materials that have attracted considerable interest from researchers because they often exhibit unexpected properties synergistically derived from the constituents. Nanometer-sized particulate fillers, for example, carbon black (CB) and silica (Si) nanoparticles, are known to form hybrids with organic polymers, which show a significant increase in their static and dynamic moduli, strength, and thermal and electrical conductivities. 

This approach towards nanostructured inorganic-organic hybrid materials is the first one to allow the synthesis of inverse-topology systems, in which the hydrophobic polymer blocks represent the outside of the microphase-separated structure. After solidification of the inorganic sol, the hydrophobic phase can be swollen with organic solvents. This procedure allows the isolation of colloidal objects, such as spheres or ceramic rods (see Fig. 12), from one another, which are sterically stabilized, because the hydrophihc block is firmly anchored in the ceramic material [45]. 

The method of sol-gel hybrid preparation is based on the growth of the inorganic phase by the hydrolysis-condensation of alkoxysilanes (Figure 5.92) like tetraethoxysilane (TEOS) in a solution containing the organic polymer. The reactions can be represented as... 

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