標題: Crystal Structure and Molecular Packing Behavior of Poly(2,3-diphenyl-1,4-phenylenevinylene) Derivatives Containing Alkyl Side-Chains
作者: Ren, Xiang-Kui
Wu, Yu-Chun
Wang, Shao-Jie
Jiang, Shi-Dong
Zheng, Jun-Feng
Yang, Shuang
Chen, Er-Qiang
Wang, Chien-Lung
Hsu, Chain-Shu
應用化學系
Department of Applied Chemistry
公開日期: 8-一月-2013
摘要: Phase behavior and crystal structure of a series of poly(2,3-diphenyl-5-alkyl-p-phenylenevinylene) (denoted as DPn-PPV, where n represents the carbon number of the alkyl side-chain, n = 6, 8, 10, 12) were studied using differential scanning calorimetry, one- and two-dimensional (1D and 2D) wide-angle X-ray diffraction (WAXD), and selected area electron diffraction (SAED). The experimental results reveal that DPn-PPV exhibits one crystalline phase at low temperatures. On the basis of 2D WAXD and SAED patterns obtained from the oriented samples, the crystal structures are determined to be orthorhombic for DP6-PPV and monoclinic for DP8-PPV, DP10-PPV, and DP12-PPV. To account for the unusually large unit cell dimensions, we propose that the unit cell of DPn-PPV contains 4 chains (8 chemical repeat units). The complex crystal structure can be attributed to the longitudinal and transverse offsets between the neighboring chains, which shall be mainly due to the requirement of minimizing the steric hindrance caused by the attached pendent groups and maximizing the pi-pi interaction between the chains. The molecular packing scheme was simulated by using Cerius(2) software, of which the result agrees with the experimental data. The polarized UV-vis absorption and polarized solid-state photoluminescence (PL) property of these polymers was also investigated. The PL spectra indicated that the light emitted from the oriented film was preferentially polarized parallel to the shear direction, implying that DPn-PPV may potentially be useful in linearly polarized luminescence devices.
URI: http://dx.doi.org/10.1021/ma302082x
http://hdl.handle.net/11536/21050
ISSN: 0024-9297
DOI: 10.1021/ma302082x
期刊: MACROMOLECULES
Volume: 46
Issue: 1
起始頁: 155
結束頁: 163
顯示於類別:期刊論文


文件中的檔案:

  1. 000313303600019.pdf