ma5b02254_si_001.pdf (759.46 kB)
Superhelices with Designed Helical Structures and Temperature-Stimulated Chirality Transitions
journal contribution
posted on 2015-12-23, 18:19 authored by Chunhua Cai, Jiaping Lin, Xingyu Zhu, Shuting Gong, Xiao-Song Wang, Liquan WangThe synthesis of multicomponent superhelices
with determined chirality
has been realized. By adding water to polymer solution in organic
solvents (tetrahydrofuran/N,N′-dimethylformamide,
THF/DMF), poly(γ-benzyl l-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) are able to
pack orderly around the surface of PBLG homopolymer bundles with designed
helical structures, e.g., right-handed and left-handed, depending
on THF/DMF ratio and temperature. A systematic investigation leads
to the construction of a temperature–organic solvent composition
phase diagram. Before the organic solvents were totally removed, the
chirality of the assemblies can be reversibly switched using temperature
stimulus. This temperature-stimulated chirality transition of polypeptide
superhelices is unprecedented. Circular dichroism (CD) experiments
indicated that the packing mode of pending phenyl groups from PBLG
chain is responsible for the determination of the helical morphologies.