Fibrils separated from polyacrylonitrile fiber by ultrasonic etching in dimethylsulphoxide solution

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 48; no. 5; pp. 617 - 619
• Main Authors: Wang, Qifen, Wang, Chengguo, Bai, Yujun, Yu, Meijie, Wang, Yanxiang, Zhu, Bo, Jing, Min, Ma, Jie, Hu, Xiuying, Zhao, Yaqi, Zhang, Min
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.03.2010; Wiley
• Subjects: Applied sciences; crystal structure; Crystallinity; crystallization; Crystals; Diffraction; dimethyl sulfoxide; Etching; Exact sciences and technology; Fibers; Fibers and threads; fibril; Forms of application and semi-finished materials; lamellar; PAN precursor; polyacrylonitrile; Polyacrylonitriles; Polymer industry, paints, wood; Reproduction; Scanning electron microscopy; structure; Technology of polymers; transmission electron microscopy; ultrasonic etching; ultrasonics; X-ray diffraction; lamellar; Synthetic fiber; Microfibril; Ultrasonic treatment; Crystallinity; Experimental study; structure; fibril; ultrasonic etching; Acrylonitrile polymer; Morphology; crystallization; PAN precursor; Growth from solution; Modified material
• ISSN: 0887-6266; 1099-0488; 1099-0488
• DOI: 10.1002/polb.21929

A novel method for the separation of polyacrylonitrile (PAN) fibrils from fibers by ultrasonic etching in a 90 wt % aqueous dimethylsulphoxide (DMSO) solution at 75 °C ± 2 °C for 6 h with a frequency of 40 kHz is demonstrated. These fibrils with a diameter of about 450 nm were systematically investigated by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and wide-angle X-ray diffraction (WAXD). It was found that the fibrils consisted of microfibrils with about 200 nm diameter, including periodic lamellae with thickness of 30-45 nm perpendicular to the fiber axis. The PAN fiber crystallinity and crystal size slightly decreased under the ultrasonic etching.