Functional Single-Chain Polymer Nanoparticles (SCPNs)
Abstract: Biomacromolecules such as proteins fold into compact, well defined, three dimensional structures which determine their properties and functions. Inspired by Nature, chemists have been trying to extract the minimum structural parameters in order to prepare synthetic polymers with the functionality of biopolymers. In recent decades, significant advances have been made in control over composition, topology and functionality of synthetic polymers, resulting in complex architecture such as cyclic, star and branched polymers, showing different properties from the classical linear chains. An additional architecture, called single chain polymer nanoparticles (SCPNs), presents unique potential, as its synthesis mimics the protein folding process through intramolecular cross-linking (folding) of individual polymer chain. While various synthetic and characterization methodologies have been developed, only few studies have focused on the functionality produced due to chain folding. In this talk, I present my investigation on the effects of chain folding on different physical and chemical properties. First, a study on chemical reactivity shows significant kinetic effects as a consequence of increase in intramolecular cross-linking. Then, this change is exploited to test the alkaline stability of quaternary ammonium (QA) groups in polyelectrolytes, revealing a remarkable improvement in stability without any tuning of the QA chemistry. Then, I show that mixtures of linear and folded chains having identical chemical composition but different topologies can phase separate, resulting in free-template formation of microporous carbon materials upon pyrolysis. Finally, ongoing studies on the effect of chain folding on the interactions with living cells is presented.