Macromolecules, Vol.49, No.8, 2948-2956, 2016
Optically Active Physical Gels with Chiral Memory Ability: Directly Prepared by Helix-Sense-Selective Polymerization
Helix-sense-selective polymerizations (HSSPs) have been attracting much attention for controlling the chirality of synthetic helical polymers. However, up to date HSSPs have provided only optically active helical polymer solutions and emulsions. The present contribution reports on the first HSSPs for directly constructing optically active physical gels (OAPGs) by using achiral substituted acetylene monomer with (R)- or (S)-1-phenylethylamine as chiral additive. The one-handed helical conformations of the resulting polymers and the optical activity of the gels thereof were verified by CD and UV vis absorption spectra. SEM images show that the OAPGs were constructed by helical nanofibers with remarkable one-handed screw sense. After complete removal of the chiral additive, the purified OAPGs and the polymers forming the gels still showed intense CD signals, demonstrating their excellent chiral memory ability. This significant advantage and the simple preparative methodology endow the OAPGs with great potentials as chiral functional materials.