title: Atomic force microscopy visualization of hard segment alignment in stretched polyurethane nanofibers prepared by electrospinning.
abstract: Molecular-level orientation within nanofibers has been attracting attention as a tool for controlling and designing highly functional nanofibers. In this study, we used atomic force microscopy to visualize the phase separation between soft and hard segments on a polyurethane (PU) nanofiber surface prepared by electrospinning. Furthermore, the stretched nanofibers prepared with a high-speed rotating collector were found to have a different phase distribution in the phase-separated structure, with the hard segment domains aligned to the fiber axis. In contrast, unstretched PU nanofibers prepared without rotation were observed to have nonuniformly distributed segments. These results indicate that the application of an intense elongation force along the nanofiber axis with a rotating mandrel collector changed the distribution of segment alignments.
authors.affiliation: Department of Frontier Fiber Technology and Science, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Asakawa
authors.affiliation: Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, Japan; Division of Electrical Engineering and Computer Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukuma
authors.affiliation: Department of Frontier Fiber Technology and Science, Graduate School of Engineering, University of Fukui, Fukui, Japan; Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujita
authors.affiliation: Department of Frontier Fiber Technology and Science, Graduate School of Engineering, University of Fukui, Fukui, Japan; Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors.forename: Shin-Ichiro
authors.initials: SI
authors.lastname: Suye
keywords: AFM; Electrospinning; Nanofiber; Phase separation; Polyurethane