Molecular orientation in aligned electrospun polyimide nanofibers by polarized FT-IR spectroscopy.
Molecular orientation in aligned electrospun polyimide nanofibers by polarized FT-IR spectroscopy.
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DOI：
10.1016/j.saa.2018.04.045
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发表时间：
2018-07
期刊：
影响因子：
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通讯作者：
Haoqi Yang;Shaohua Jiang;Hong Fang;Xiaowu Hu;Gaigai Duan;Haoqing Hou
中科院分区：
文献类型：
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作者：
Haoqi Yang;Shaohua Jiang;Hong Fang;Xiaowu Hu;Gaigai Duan;Haoqing Hou
随着酰亚胺化温度的升高，定向静电纺丝聚酰亚胺（PI）纳米纤维的力学性能得到了改善，这是非常需要定量解释的。在这项工作中，偏振傅立叶变换红外光谱是用来解决这个问题。基于偏振红外光谱和纤维中的分子模型，研究了PI分子的重复单元长度、纤维轴与酰亚胺环上羰基对称伸缩方向的夹角以及PI分子轴与纤维轴的夹角。使用Mark-Howink方程计算PI分子的数均摩尔质量。从PI分子的数均摩尔质量和纤维的平均直径研究了PI分子在静电纺纳米纤维中的取向状态。通过偏振傅立叶变换红外光谱对静电纺纳米纤维中PI分子的取向因子进行了定量分析。
Quantitative explanation on the improved mechanical properties of aligned electrospun polyimide (PI) nanofibers as the increased imidization temperatures is highly required. In this work, polarized FT-IR spectroscopy is applied to solve this problem. Based on the polarized FT-IR spectroscopy and the molecular model in the fibers, the length of the repeat unit of PI molecule, the angle between the fiber axis and the symmetric stretching direction of carbonyl group on the imide ring, and the angle between the PI molecular axis and fiber axis are all investigated. The Mark-Howink equation is used to calculate the number-average molar mass of PI molecules. The orientation states of PI molecules in the electrospun nanofibers are studied from the number-average molar mass of PI molecules and the average fiber diameter. Quantitative analysis of the orientation factor of PI molecules in the electrospun nanofibers is performed by polarized FT-IR spectroscopy.