Abstract Understanding the molecular orientation of electrospun fibers is a key challenge for tailoring fiber properties. The studies of electric field distribution, and the motion of the initial portion of the polymer jet, are of interest for clarifying molecular orientation in fibers during electrospinning. In this work, we study the impact of electric field distribution and the initial jet motion induced by two kinds of spinneret configurations, referred to as a needle configuration and a hole configuration, on molecular orientation in electrospun PEO fibers. Using FE-SEM, FTIR and WAXD techniques, the fiber diameter and molecular orientation of the fibers prepared with the needle electrospinning system and the hole electrospinning system are characterized. To explore jet stretching and chain orientation during the spinning process, electric field simulation and high-speed photography are performed to obtain the electric field characteristics and to measure the initial jet velocities for the needle and the hole systems. Our results reveal the higher electric field strength around the spinneret and the larger initial jet velocities, which depend on the spinneret configuration, result in the higher degree of molecular orientation in fibers.

中文翻译：

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电纺纤维中分子取向的喷丝头配置引起的电场分布和初始射流运动

摘要 了解电纺纤维的分子取向是定制纤维特性的关键挑战。电场分布的研究和聚合物射流初始部分的运动对于阐明静电纺丝过程中纤维中的分子取向很有意义。在这项工作中，我们研究了电场分布和由两种喷丝头配置（称为针配置和孔配置）引起的初始射流运动对电纺 PEO 纤维中分子取向的影响。使用FE-SEM、FTIR和WAXD技术，表征了用针静电纺丝系统和孔静电纺丝系统制备的纤维的纤维直径和分子取向。探索纺纱过程中的射流拉伸和链取向，进行电场模拟和高速摄影以获得电场特性并测量针和孔系统的初始射流速度。我们的结果表明，喷丝头周围较高的电场强度和较大的初始射流速度（取决于喷丝头配置）导致纤维中更高程度的分子取向。