47 research outputs found

    Microstructure of chemically modified wood using X-ray computed tomography in relation to wetting properties

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    X-ray computed tomography (XCT) was utilized to visualize and quantify the 2D and 3D microstructure of acetylated southern yellow pine (pine) and maple, as well as furfurylated pine samples. The total porosity and the porosity of different cell types, as well as cell wall thickness and maximum opening of tracheid lumens were evaluated. The wetting properties (swelling and capillary uptake) were related to these microstructural characteristics. The data show significant changes in the wood structure for furfurylated pine sapwood samples, including a change in tracheid shape and filling of tracheids by furan polymer. In contrast, no such changes were noted for the acetylated pine samples at the high resolution of 0.8 mu m. The XCT images obtained for the furfurylated maple samples demonstrated that all ray cells and some vessel elements were filled with furan polymer while the fibers largely remained unchanged. Furfurylation significantly decreased the total porosity of both the maple and pine samples. Furthermore, this was observed in both earlywood (EW) and latewood (LW) regions in the pine samples. In contrast, the total porosity of pine samples was hardly affected by acetylation. These findings are in line with wetting results demonstrating that furfurylation reduces both swelling and capillary uptake in contrast to acetylation which reduces mostly swelling. Furfurylation significantly increased the cell wall thickness of both the maple and pine samples, especially at higher levels of furfurylation

    Superhydrophobic surfaces manufacturing with nanocellulose

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    Researchers in natural fibers see opportunities in superhydrophobicity for fabrics or paper. The first challenge with natural fiber is their high hydrophilicity when the second is the perpetual search for water born coating  in papermaking. These challenges were overcome by a one pot formulation comprising a latex binder, precipitated calcium carbonate and  fatty acids to give their hydrophobicity to pigments 1.  In this study, we want to go further by replacing the petro-sourced latex with a new kind of fibers that are cellulose nanofibers (CNF). Inspired by the Lotus leaf, superhydrophobic surfaces have been a center of interest in the last decade because of their high potential in industry for a variety of applications.  It is seen as the next generation of surface for anti-fouling and corrosive retardant in navy industry but also  in general  anti corrosive materials industry.  Now widely studied , mechanisms for manufacturing superhydrophobicity are well understood. Born from the alliance of low surface energy chemistry and physical structuration of surface, superhydrophobic materials give a water contact angle above 150° and a slidding angle below 10°

    Superhydrophobic surfaces manufacturing with nanocellulose

    No full text
    Researchers in natural fibers see opportunities in superhydrophobicity for fabrics or paper. The first challenge with natural fiber is their high hydrophilicity when the second is the perpetual search for water born coating  in papermaking. These challenges were overcome by a one pot formulation comprising a latex binder, precipitated calcium carbonate and  fatty acids to give their hydrophobicity to pigments 1.  In this study, we want to go further by replacing the petro-sourced latex with a new kind of fibers that are cellulose nanofibers (CNF). Inspired by the Lotus leaf, superhydrophobic surfaces have been a center of interest in the last decade because of their high potential in industry for a variety of applications.  It is seen as the next generation of surface for anti-fouling and corrosive retardant in navy industry but also  in general  anti corrosive materials industry.  Now widely studied , mechanisms for manufacturing superhydrophobicity are well understood. Born from the alliance of low surface energy chemistry and physical structuration of surface, superhydrophobic materials give a water contact angle above 150° and a slidding angle below 10°
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