Noncovalent Interaction with Polymers

Dai, " and coworkers, and others.Nanotubes have been known to adsorb gas molecules (H2, N2, O2, and H2O) through adsorption. " Some polymers have strong noncovalent interactions with the carbon nanotubes. High molecular weight ionic or electron-rich polymers coat or wrap themselves around the carbon nanotubes. Polyvinyl pyrrolidone and polystyrene sulfonate and their copolymers, polyvinyl sulfate, and poly (metaphenylene vinylene) have been used to wrap around The wrapping... 

Figure 5.1 The charts suggest how a maleated polymer can noncovalently interact with a matrix resin, and covalently interact with chemical functional groups of a filler or other polymers in the blend (provided by Du Pont, courtesy David Dean [upper] and Crompton, courtesy Bill Sigworth [lower]).

Subsequently, this strategy was employed to functionalize poly(e-caprolactone) with the same UPy synthon this resulted in the formation of biocompatible supramolecular polymers. This, in turn, allowed the introduction of bioactivity into the material, as UPy-functionalized peptides could be easily incorporated via noncovalent interactions with the UPy groups present in the supramolecular polymer. This modular approach enabled the straightforward introduction of a variety of peptides, thereby creating materials with tunable bioactivities [14] (Figure 34.4). 

Poly(ADP-ribose) metabolism is a chromatin associated event. The function of poly-(ADP-ribose) may be mediated by activation or inactivation of enzymatic activities by the covalent binding of the polymer and/or by noncovalent interactions of this highly negatively charged polymer with other chromatin components. We have studied the size distribution and branching frequency of polymers in order to evaluate the potential importance on noncovalent interactions with other components of chromatin. 

Unlike the covalent functionalization approach, noncovalent functionalization provides an alternative method to modify and tailor the surface properties of CNTs in order to increase their solubility in solvents or compatibility with polymer matrix. In this method, the tubular surface of a CNT is noncovalently wrapped with polymer chains due to van der Waals attractive forces or through tt-tt interactions. This noncovalent wrapping approach has also been widely used and is particularly attractive because it offers the possibility of attaching chemical handles without affecting the electronic network of the nanotubes [42-45]. Coleman et al [46-49] illustrated an example of noncovalent wrapping by tt-tt interaction between CNTs and poly(m-phenylenevinylene-co-2,5-dioctoxy-p-phenylene vinylene) (PmPV), a conjugated luminescent polymer, to obtain a CNT-PmPV composite. 

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