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In-Depth Information
Figure 5.21 Orthogonal noncovalent cross-linking as well as functionalization strategy of
terpolymer using hydrogen bonding and metal coordination interactions.
bonded analogue. The independent, noninteracting behaviors of these two modes of
self-assembly allowed for the creation of a self-assembled, multifunctional, and
cross-linked material in one self-assembly step.
The reversibility of this system was also studied. The polymer scaffold could be
fully defunctionalized and decross-linked by 1) heating to disrupt the hydrogen
bonds (thus exhibiting thermoresponsiveness) and 2) addition of PPh
3
to break the
metal-pyridine complex via competitive ligand interaction (thus exhibiting chemor-
esponsiveness). Hence, by employing different noncovalent interactions, we can
design a system that is responsive to multiple stimuli, opening the potential for the
easy fabrication of “smart materials.”
5.5. CONCLUSIONS AND OUTLOOK
In conclusion, we can say with certainty that supramolecular side chain functiona-
lized polymers combine the best of both worlds of covalent polymer formation
and side chain functionalization through noncovalent interactions. This synergistic
combination of two very successful areas of science confers the distinct advantage
of using such a strategy for materials design and optimization. The ongoing develop-
ment of synthetic polymer chemistry and supramolecular science will greatly benefit
the synthesis of more complex controlled polymer architectures using side chain
functionalization. The self-assembly strategies presented in this chapter represent
only a small selection from the now vast amount of research in this still rapidly
expanding area of multifunctional materials based on noncovalent interactions. As
the field of functional materials design and synthesis continues to demand smaller
and smaller size ranges for increasingly complex devices and applications, self-
assembly will have to emerge as the most important tool available to scientists for
