TY - JOUR
T1 - Hierarchical structure of the triclinic α-phase crystal in nylon 6,12 mediated by two-dimensional confinement
AU - Lai, Ziwei
AU - Zhang, Shuailin
AU - Zheng, Nan
AU - Yu, Shichen
AU - Ageishi, Masaki
AU - Jinnai, Hiroshi
AU - Cao, Yan
N1 - Funding Information:
We are thankful for the funding support of the National Science Foundation of China (802-008992), the Guangdong Natural Science Foundation (85118-000036), and the Shenzhen Science and Technology Innovation Foundation (85135-000017). Special thanks for the support of the Foundation of Shenzhen Peacock Talent (827-000150).
Publisher Copyright:
© 2020.
PY - 2020/2/1
Y1 - 2020/2/1
N2 - It has been recognized that macromolecular chains can self-assemble into a hierarchical structure from lamellae to spherulites in bulk crystallization. However, little account has been taken of crystal symmetry effects on the hierarchical nanostructure in polymers under cylindrical confinement. In this research, a model polymer, nylon 6,12, most commonly occurring in the triclinic α phase, was chosen in order to demonstrate the effect of triclinic symmetry on the 2D-constrained polymer nanostructure. The self-arranging unit of nylon 6,12 takes various forms, including stems, unit cells, hydrogen-bonded sheets, lamellae and complex spherulites, which is an essential structural feature for investigating hierarchical nanostructure. The rod nanostructure in confinement was examined by cross-checking electron and X-ray diffraction techniques. It is found that the a*axis of the α-phase cell is inclined at about ±6-11° to the rod long axis within the a*b*plane around the c axis (c axis ⊥ rod long axis). The rotation of the a*b*plane most likely results from the impact of the triclinic symmetry on the molecular chain packing under 2D confinement. A mechanism for this a*b*plane tilting is proposed.
AB - It has been recognized that macromolecular chains can self-assemble into a hierarchical structure from lamellae to spherulites in bulk crystallization. However, little account has been taken of crystal symmetry effects on the hierarchical nanostructure in polymers under cylindrical confinement. In this research, a model polymer, nylon 6,12, most commonly occurring in the triclinic α phase, was chosen in order to demonstrate the effect of triclinic symmetry on the 2D-constrained polymer nanostructure. The self-arranging unit of nylon 6,12 takes various forms, including stems, unit cells, hydrogen-bonded sheets, lamellae and complex spherulites, which is an essential structural feature for investigating hierarchical nanostructure. The rod nanostructure in confinement was examined by cross-checking electron and X-ray diffraction techniques. It is found that the a*axis of the α-phase cell is inclined at about ±6-11° to the rod long axis within the a*b*plane around the c axis (c axis ⊥ rod long axis). The rotation of the a*b*plane most likely results from the impact of the triclinic symmetry on the molecular chain packing under 2D confinement. A mechanism for this a*b*plane tilting is proposed.
KW - crystal structure prediction
KW - materials modeling
KW - molecular simulation
KW - nanostructure
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U2 - 10.1107/S1600576719014705
DO - 10.1107/S1600576719014705
M3 - Article
AN - SCOPUS:85079094297
VL - 53
SP - 27
EP - 33
JO - Journal of Applied Crystallography
JF - Journal of Applied Crystallography
SN - 0021-8898
ER -