Enthalpy-Driven Transition of Liquid Crystalline Textures of Poly(2-cyano-p-phenylene terephthalamide) in N,N-Dimethyl Acetamide/Lithium Chloride
- Title
- Enthalpy-Driven Transition of Liquid Crystalline Textures of Poly(2-cyano-p-phenylene terephthalamide) in N,N-Dimethyl Acetamide/Lithium Chloride
- Author
- 김병철
- Keywords
- para-aramids; liquid crystals; cholesteric; FTIR; 2D correlation spectroscopy
- Issue Date
- 2019-04
- Publisher
- SPRINGER
- Citation
- MACROMOLECULAR RESEARCH, v. 27, NO 4, Page. 404-411
- Abstract
- The solution of poly(2-cyano-p-phenylene terephthalamide) (CY-PPTA) in N,N-dimethyl acetamide/lithium chloride exhibited a concentration-dependent transition of liquid crystalline textures from nematic-rich to cholesteric-rich with increasing concentration above the critical concentration. The 2D correlation analysis of the FTIR spectra revealed that the dipolar interactions between cyano groups of the polymer increased as concentration increased. The polarized cyano group withdrew the delocalized -electrons in the C-N bond of the amide group of the polymer, increasing its single bond character. The molecular simulation based on this spectroscopic evidence proposed a change of molecular shapes of CY-PPTA from linear rigid rod to semi-rigid helix. The semi-rigid helical conformation where the single bond character was prevalent over the delocalized one in the C-N bond would develop a cholesteric liquid crystalline texture.
- URI
- https://link.springer.com/article/10.1007%2Fs13233-019-7058-8https://repository.hanyang.ac.kr/handle/20.500.11754/110624
- ISSN
- 1598-5032; 2092-7673
- DOI
- 10.1007/s13233-019-7058-8
- Appears in Collections:
- COLLEGE OF ENGINEERING[S](공과대학) > ORGANIC AND NANO ENGINEERING(유기나노공학과) > Articles
- Files in This Item:
There are no files associated with this item.
- Export
- RIS (EndNote)
- XLS (Excel)
- XML