Abstract

AGUILA-LOPEZ, Josefina et al. Controlled preparation and chemical actuation of polyacrylonitrile microfibers. Biotecnia [online]. 2023, vol.25, n.3, pp.189-196.  Epub May 27, 2024. ISSN 1665-1456.  https://doi.org/10.18633/biotecnia.v25i3.2122.

Pure polyacrylonitrile fibers with diameter size at micrometric scale were obtained and collected radially using an immersion-jet wet spinning system. High purity polyacrylonitrile powder was used as precursor polymer. This method is a fast and easy approach to fabricate micrometric PAN fibers. Fiber diameter can be easily controlled by adjusting the size of the spinneret. Uniform, smooth and continuous PAN microfibers were suitable modified by thermal stabilization and alkaline hydrolysis to obtain pH-sensitive fibers. The effect of diameter size fiber on the chemical actuation behavior was investigated in terms of length change characteristics under the influence of pH solutions. The microfibers showed expanding/contracting behavior and force generation stimulated by changes in pH from 1-14. By means of scanning electron microscopy, the formation of PAN fibers with diameters on the micrometer scale of 91-287 µm could be corroborated. FT-IR spectroscopy revealed that the nitrile (C≡N) groups of PAN were converted to carboxylic groups (COOH), which are necessary to provide the deformation of the PAN gel microfibers.

Keywords : Microfabrication; Microfiber; Polyacrylonitrile; Chemical Actuation.