In this study, PAN-based carbon nanofibers (CNFs) were synthesized via electrospinning followed by stabilizing and carbonization. The carbonization process was performed by heating the fibrous mats up to a maximum temperature in the region of 800–1600 °C. The effect of carbonization maximal temperature on the structure and tensile strength of carbon nanofiber mats was investigated via SEM, elemental analysis, X-ray diffraction, Raman spectroscopy and tensile testing. Polyacrylonitrile (PAN) concentrations of 6–10% (w/w) and voltages of 14–16 kV were recognized as the optimal electrospinning parameters in order to synthesize of nanofibrous mats without any agglomerated nanoparticles or beads in the mats structure. It is clear from the results that carbon content, crystalline stacking size (Lc), in-plane crystallite size (La) and the number of graphene layers in single crystallite continuously increased with rising carbonization maximum temperature from 800 to 1600 °C, while interlayer d-spacing (d 002 ) decreased at the maximum temperatures of 1000–1400 °C, firstly. This value increased again at the maximum temperatures above1400 °C due to the formation of considerable shrinkages and pores in the CNFs structure. The highest value of tensile strength (206–223 MPa) was recorded for the CNFs mats carbonized up to 1200–1400 °C.

中文翻译：

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电纺PAN基碳纳米纤维的主要结构和机械性能随碳化最高温度的变化

在这项研究中，PAN 基碳纳米纤维 (CNF) 通过静电纺丝、稳定和碳化合成。碳化过程是通过将纤维垫加热到 800-1600 °C 的最高温度来进行的。通过SEM、元素分析、X射线衍射、拉曼光谱和拉伸测试研究了碳化最高温度对碳纳米纤维垫结构和拉伸强度的影响。聚丙烯腈 (PAN) 浓度为 6-10% (w/w) 和电压为 14-16 kV 被认为是最佳静电纺丝参数，以合成纳米纤维垫，而垫结构中没有任何团聚的纳米颗粒或珠子。结果表明，碳含量、结晶堆积尺寸（Lc）、随着碳化最高温度从 800°C 升高到 1600°C，单晶中的面内微晶尺寸 (La) 和石墨烯层数不断增加，而层间 d-间距 (d 002 ) 在 1000-1400°C 的最高温度下减小C、首先。由于在 CNF 结构中形成了相当大的收缩和孔隙，该值在高于 1400 °C 的最高温度下再次增加。碳化温度高达 1200-1400 °C 的 CNFs 垫的拉伸强度最高值 (206-223 MPa)。由于在 CNF 结构中形成了相当大的收缩和孔隙，该值在高于 1400 °C 的最高温度下再次增加。碳化温度高达 1200-1400 °C 的 CNFs 垫的拉伸强度最高值 (206-223 MPa)。由于在 CNF 结构中形成了相当大的收缩和孔隙，该值在高于 1400 °C 的最高温度下再次增加。碳化温度高达 1200-1400 °C 的 CNFs 垫的拉伸强度最高值 (206-223 MPa)。