Functional Polymer Blends and Nanocomposites

The broad class of (multi)functional polymers with unusual combinations of optical, electronic, mechanical and other properties is attracting significant interest, because it conceptually combines the advantages of polymers - low cost, ease of processing and a range of attractive mechanical characteristics - with the specific, tailorable properties of functional organic molecules. The caveat is that the synthesis of functional polymers is frequently complex and involves many steps, which makes the technological exploitation of new materials difficult. One alternative strategy is the fabrication of functional polymer blends and nanocomposites. Rather than synthesizing new, complex functional macromolecules, minor fractions of a 'functional additive' are mixed with a matrix polymer in order to create, often after using rather specific processing protocols, new materials with unique or unusual property matrices. This review discusses three specific examples - chameleon polymers with integrated sensing capabilities, optically upconverting polymers, and mechanically adaptive nanocomposites - to showcase the conceptual simplicity, elegance, and broad applicability of this general design approach.