|
1
|
Zhi XX, Wang HS, Jia J, Gao YS, Wang XL, Zhang Y, Liu JG. Preparation and properties of laterally tert-butyl-substituted cyclohexyl-containing polyimide alignment layers with high pretilt angles for potential applications in twisted-nematic TFT-LCDs. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03262-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
|
2
|
Nguyen TT, Khuat HTT, Asakura S, Mizutani G, Murakami Y, Okada T. Study of the molecular orientation of steroidal side chains at polyimide surfaces using sum frequency generation vibrational spectroscopy. J Chem Phys 2021; 155:084702. [PMID: 34470358 DOI: 10.1063/5.0057145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The molecular orientation of steroidal side chains at rubbed polyimide (PI) surfaces is studied by sum frequency generation (SFG) vibrational spectroscopy. The main objective is to find a correlation between the molecular structure of the PI film and the liquid crystal alignment on the polymer. Analysis of the SFG spectra shows that rubbing of the polymer film appears to cause conformational changes in the methyl group of the polymer side chain near the steroidal structure. However, rubbing does not significantly influence the orientation of the isopropyl group at the end of the polymer side chain. This shows that the liquid crystal alignment is not correlated with the orientation of the isopropyl group.
Collapse
Affiliation(s)
- Trinh Thi Nguyen
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Hien Thi Thu Khuat
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Shinya Asakura
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Goro Mizutani
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Yoshitaka Murakami
- LCD Materials 2nd Laboratory, Display Materials Research Laboratories, JSR Corporation, Mie 510-8552, Japan
| | - Takashi Okada
- LCD Materials 2nd Laboratory, Display Materials Research Laboratories, JSR Corporation, Mie 510-8552, Japan
| |
Collapse
|
|
4
|
Bi HS, Zhi XX, Wu PH, Zhang Y, Wu L, Tan YY, Jia YJ, Liu JG, Zhang XM. Preparation and Characterization of Semi-Alicyclic Polyimide Resins and the Derived Alignment Layers for Liquid Crystal Display Technology. Polymers (Basel) 2020; 12:polym12010217. [PMID: 31952358 PMCID: PMC7023591 DOI: 10.3390/polym12010217] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/11/2020] [Accepted: 01/12/2020] [Indexed: 11/16/2022] Open
Abstract
Uniform alignment of rigid-rod liquid crystal (LC) molecules under applied voltage is critical for achievement of high-quality display for thin-film transistor-driven liquid crystal display devices (TFT-LCDs). The polymeric components that can induce the alignment of randomly aligned LC molecules are called alignment layers (ALs). In the current work, a series of organo-soluble polyimide (SPI) ALs were designed and prepared from an alicyclic dianhydride, hydrogenated 3,3',4,4'-biphenyltetracarboxylic dianhydride (HBPDA), and various aromatic diamines, including 4,4'-methylenedianiline (MDA) for SPI-1, 4,4'-aminodianiline (NDA) for SPI-2, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) for SPI-3, and 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane (DMDEDA) for SPI-4. The derived SPI resins were all soluble in N-methyl-2-pyrrolidone (NMP). Four SPI alignment agents with the solid content of 6 wt.% were prepared by dissolving the SPI resins in the mixed solvent of NMP and butyl cellulose (BC) (NMP/BC = 80:20, weight ratio). Liquid crystal minicells were successfully fabricated using the developed SPI varnishes as the LC molecule alignment components. The SPI ALs showed good alignment ability for the LC molecules with the pretilt angles in the range of 1.58°-1.97°. The LC minicells exhibited good optoelectronic characteristics with voltage holding ratio (VHR) values higher than 96%. The good alignment ability of the SPI ALs is mainly attributed to the good comprehensive properties of the SPI layers, including high volume resistivity, high degree of imidization at the processing temperature (230 °C), good rubbing resistance, good thermal stability with glass transition temperatures (Tgs) higher than 260 °C, and excellent optical transparency with the transmittance higher than 97% at the wavelength of 550 nm.
Collapse
Affiliation(s)
- Hong-sheng Bi
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Xin-xin Zhi
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Peng-hui Wu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Yan Zhang
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Lin Wu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Yao-yao Tan
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Yan-Jiang Jia
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
| | - Jin-gang Liu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; (H.-s.B.); (X.-x.Z.); (P.-h.W.); (Y.Z.); (L.W.); (Y.-y.T.); (Y.-J.J.)
- Correspondence: (J.-g.L.); (X.-m.Z.); Tel.: +86-10-8232-2972 (J.-g.L. & X.-m.Z.)
| | - Xiu-min Zhang
- School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044, China
- Correspondence: (J.-g.L.); (X.-m.Z.); Tel.: +86-10-8232-2972 (J.-g.L. & X.-m.Z.)
| |
Collapse
|
|
6
|
Yi LF, Xia SL, Sun Z, Liu MS, Wang YH. A study of the stabilization of vertical alignment for liquid crystals by increasing the side-chain rigidity of polyimides. POLYM INT 2012. [DOI: 10.1002/pi.4345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|