Mesopores variation in polyacrylonitrile fibers during dry-jet wet spinning process

  • Quan Gao
  • Min Jing
  • Chengguo WangEmail author
  • Meiling Chen
  • Shengyao Zhao
  • Wenli Wang
  • Jianjie Qin
Original Research


The mesopore structures in polyacrylonitrile (PAN) fibers during dry-jet wet spinning process were investigated by high-resolution transmission electron microscopy (HRTEM) and image analysis utilizing the ultrathin section technique. The morphologies and dimension distribution of the mesopores in the surface and core regions of the nascent fibers and PAN fibers are presented. All fibers exhibited lamellar-like structures perpendicular to the fiber axis and the mesopores were distributed between the lamellae. For nascent fibers, the size and volume of the mesopores increased with increasing air gap and decreased with increasing drawing ratio. In addition, the widths of the mesopores were larger than their lengths. Consequently, the size and content of the mesopores in nascent fibers could be adjusted by controlling coagulation conditions. During the post-spinning process, the size and volume of the mesopores in PAN fibers decreased efficiently by hot drawing in a hot water washing bath, in hot steam chambers or on hot rollers. Moreover, the lengths of the mesopores were larger than their widths. In all fiber samples, the number and size of the mesopores in the core region were larger than those in the surface region. In addition, the mechanical properties of fibers were correlated with dimension of the mesopores. Their tensile strength increased with decreasing mesopore widths and lengths.


PAN fiber Nascent fiber Mesopore Ultrathin section Mechanical properties 



This work was supported by the National Natural Science Foundation, China (Grant nos. 51773110 and 51573087) and the Natural Science Foundation of Shandong Province, China (Grant nos. ZR2016EMM16 and ZR2018BEM036).

Supplementary material

13726_2019_699_MOESM1_ESM.docx (358 kb)
Supplementary material 1 (DOCX 357 KB)


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Copyright information

© Iran Polymer and Petrochemical Institute 2019

Authors and Affiliations

  • Quan Gao
    • 1
    • 2
  • Min Jing
    • 3
  • Chengguo Wang
    • 1
    • 2
    Email author
  • Meiling Chen
    • 1
    • 2
  • Shengyao Zhao
    • 1
    • 2
  • Wenli Wang
    • 1
    • 2
  • Jianjie Qin
    • 1
    • 2
  1. 1.Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education)Shandong UniversityJinanChina
  2. 2.Carbon Fiber Engineering Research Center, School of Material Science and EngineeringShandong UniversityJinanChina
  3. 3.School of Material Science and EngineeringShandong Jianzhu UniversityJinanChina

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