title: Controlled Handedness of Twisted Lamellae in Banded Spherulites of Isotactic Poly(2-vinylpyridine) as Induced by Chiral Dopants.
abstract: Herein, we suggest a unique approach to control the handedness of twisted lamellae in banded spherulites of a stereoregular polymer, isotactic poly(2-vinylpyridine) (iP2VP). When (R)- or (S)-hexahydromandelic acid (HMA), which can associate with iP2VP, was introduced as a chiral dopant, mirror-image CD spectra in the complex systems showed induced circular dichroism (ICD) of the iP2VP by chiral HMA. Banded spherulites resulting from lamellar twisting due to the imbalanced stresses at the opposite folding surfaces could be formed by crystallization of the iP2VP/HMA complexes, which had a crystalline structure similar to that of neat iP2VP. A preferential sense of the twisted crystalline lamellae was found in the iP2VP/HMA complex, thus suggesting homochiral evolution from conformational to hierarchical chirality.
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013 (Taiwan).
authors.forename: Tao
authors.initials: T
authors.lastname: Wen
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013 (Taiwan).
authors.forename: Han-Yun
authors.initials: HY
authors.lastname: Shen
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013 (Taiwan).
authors.forename: Hsiao-Fang
authors.initials: HF
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering, National Chung Cheng University, Chiayi, 62102 (Taiwan).
authors.forename: Yung-Cheng
authors.initials: YC
authors.lastname: Mao
authors.affiliation: National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076 (Taiwan).
authors.forename: Wei-Tsung
authors.initials: WT
authors.lastname: Chuang
authors.affiliation: Department of Chemical Engineering, National Chung Cheng University, Chiayi, 62102 (Taiwan).
authors.forename: Jing-Cherng
authors.initials: JC
authors.lastname: Tsai
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013 (Taiwan). rmho@mx.nthu.edu.tw.
authors.forename: Rong-Ming
authors.initials: RM
authors.lastname: Ho
keywords: chiral dopants; chirality; crystal growth; helical structures; polymers