Controlled fabrication of polymer nanofibers via conventional free radical polymerization using diurea xerogel fibers as the templates

Polymer nanofibers with smooth surface were fabricated via conventional free radical polymerization of diurea type supramolecular gel fibers in cyclohexane. As the solvent polarity by using toluene increased, the product yield and fiber size increased, while the fibers changed from smooth to rough, together with more and more free particles. In the presence of polar methacrylic acid, both rough fibers and free particles were obtained when polymerized in cyclohexane. When nonpolar 2-(perfluoro-3-methylbutyl)ethyl acrylate (R-3420) was used, only polymer fibers with very smooth surface were formed. The morphologies of fluoropolymer samples changed from fibers to particles, while the fiber surface became rougher and rougher, as more and more ethanol was used. The hydrophobic fluoropolymer sample could extract toluene from water-toluene two-phase system. Compared with granular fluoropolymer samples, fibrous fluoropolymer samples displayed higher specific surface area and higher swelling ratio in toluene, and required a shorter time for toluene to flow through them.