Coil-to-globule transition of poly(N-isopropylacrylamide) doped with chiral amino acidic comonomers

Light scattering and circular dichroism measurements (CD) are used to investigate the coil-to-globule transition of the thermosensitive polymer poly(N-isopropylacrylamide) (pNIPAAm) copolymerized with a fraction of valine- or leucine-derived groups randomly positioned along the chains. The CD signal of the chiral comonomers is found to depend on the local chain density, indicating the behavior as an effect of the whole chain conformation on the conformations accessible to the chiral groups.