Nanopaper membranes from chitin–protein composite nanofibers—structure and mechanical properties

Authors

  • Ngesa Ezekiel Mushi,

    Corresponding author
    1. Department of Fiber and Polymer Technology, Royal Institute of Technology, Stockholm, Sweden
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  • Nuria Butchosa,

    1. Department of Fiber and Polymer Technology, Royal Institute of Technology, Stockholm, Sweden
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  • Qi Zhou,

    1. School of Biotechnology, Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
    2. Wallenberg Wood Science Center, Royal Institute of Technology, Stockholm, Sweden
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  • Lars A Berglund

    1. Department of Fiber and Polymer Technology, Royal Institute of Technology, Stockholm, Sweden
    2. Wallenberg Wood Science Center, Royal Institute of Technology, Stockholm, Sweden
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  • The copyright line for this article was changed on 25 January 2016 after original online publication

ABSTRACT

Chitin nanofibers may be of interest as a component for nanocomposites. Composite nanofibers are therefore isolated from crab shells in order to characterize structure and analyze property potential. The mechanical properties of the porous nanopaper structures are much superior to regenerated chitin membranes. The nanofiber filtration-processing route is much more environmentally friendly than for regenerated chitin. Minerals and extractives are removed using HCl and ethanol, respectively, followed by mild NaOH treatment and mechanical homogenization to maintain chitin–protein structure in the nanofibers produced. Atomic force microscope (AFM) and scanning transmission electron microscope (STEM) reveal the structure of chitin–protein composite nanofibers. The presence of protein is confirmed by colorimetric method. Porous nanopaper membranes are prepared by simple filtration in such a way that different nanofiber volume fractions are obtained: 43%, 52%, 68%, and 78%. Moisture sorption isotherms, structural properties, and mechanical properties of membranes are measured and analyzed. The current material is environmentally friendly, the techniques employed for both individualization and membrane preparation are simple and green, and the results are of interest for development of nanomaterials and biocomposites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40121.

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