Title
Self‐Assembly and Responsive Behavior of Poly(peptide)‐Based Copolymers
Author
Avneesh Kumar, Brigitte Hertel, Klaus Müllen
Year
2018
Journal
Macromolecular Chemistry and Physics
Abstract
Well‐defined copolymers synthesized by combining poly(ethylene glycol) (PEG) and amino acid based building blocks are investigated with regard to their helical rigidity and self‐assembly. Optical active block copolymers reported here are designed to have a pendant amino acid and polymerizable group, that is, isonitrile in order to induce helix formation and reduce the mobility of polymer chains by forming a hydrogen bond network so that a helix with reasonable rigidity can be obtained. Due to the amphiphilicity and a relatively shorter PEG as a coil, these polymers form micelles as observed under transmission electron microscopy in which copolymers PEG108‐b‐PPIC764 and PEG108‐b‐PPIC1020 appear to be evolving into nanoparticles with a size distribution of 100–200 nm. Circular dichroism spectroscopy is employed to study the nature of the helix and its rigidity. The folding and unfolding of polymer helix as a result of the ability of a selective solvent to form/disrupt hydrogen bonds with the peptide linkage is also discussed to highlight the responsive nature of the polymer.
Instrument
J-720
Keywords
Circular dichroism, Polymers, Chemical stability, Cotton effect