Two core–shell-structured polystyrene/poly(vinyl pyrrolidone) (PS/PVP) and PVP/PS composite fibers were prepared via coaxial electrospinning in this study. Different concentrations of PVP solutions with a variety of viscosities and conductivities were adopted in the experiment. The influences of both viscosity and conductivity on the Taylor cone, jet motion, morphology, and internal structure of the resultant core–shell fiber were investigated in a comprehensive and systematic manner. As shown in the images of Taylor cone and jet motion, which were captured by a high-speed camera, different PVP concentrations in the core and shell would result in different core and shell thicknesses as well as distinct jet motion patterns including straight jet length, envelop angle, and frequency of whipping process, thus obtaining the core–shell fibers with different diameters. Not only jet motion and Taylor cone but also the polymer solution concentration and the role of PVP in core and shell have a tremendous influence on the morphology and the internal structure of the resultant core–shell fiber. Additionally, the formation mechanisms of PS/PVP and PVP/PS fibers were studied by means of Fourier transform infrared (FTIR). The experimental results provide a basis for further design and optimization of processing conditions, so as to control the nanostructure of core–shell composite fibers.

中文翻译：

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同轴静电纺丝：射流运动，核壳纤维形态和结构作为材料参数的函数

在这项研究中，通过同轴电纺制备了两种核-壳结构的聚苯乙烯/聚乙烯吡咯烷酮（PS / PVP）和PVP / PS复合纤维。实验中采用了不同浓度的具有不同粘度和电导率的PVP溶液。全面，系统地研究了粘度和电导率对泰勒锥，射流运动，形态和所得核壳纤维内部结构的影响。如高速相机拍摄的泰勒锥和喷射运动的图像所示，核和壳中不同的PVP浓度会导致核和壳的厚度不同以及喷射运动方式不同，包括直线喷射长度，包角和搅打过程的频率，从而获得不同直径的核壳纤维。不仅喷射运动和泰勒锥，而且聚合物溶液的浓度以及PVP在核和壳中的作用都对所得核-壳纤维的形态和内部结构产生巨大影响。另外，利用傅立叶变换红外光谱（FTIR）研究了PS / PVP和PVP / PS纤维的形成机理。实验结果为进一步设计和优化工艺条件提供了基础，从而控制了核壳复合纤维的纳米结构。利用傅立叶变换红外光谱（FTIR）研究了PS / PVP和PVP / PS纤维的形成机理。实验结果为进一步设计和优化工艺条件提供了基础，以控制核-壳复合纤维的纳米结构。利用傅立叶变换红外光谱（FTIR）研究了PS / PVP和PVP / PS纤维的形成机理。实验结果为进一步设计和优化工艺条件提供了基础，从而控制了核壳复合纤维的纳米结构。