Novel Insight into the Intricate Shape of Flax Fibre Lumen

Fibers

Hom Dhakal¹  Alexander Kao²  Franck Callebert³  Johnny Beaugrand⁴  Sofiane Guessasma⁴  Emmanuelle Richely⁴  Sylvie Durand⁴  Tatyana Gorshkova⁵  Alain Bourmaud⁶  Alessia Melelli⁶  Anthony Magueresse⁶ 

[1] AMM Research Group, University of Portsmouth, Hampshire PO13DJ, UK;Elettra Sincrotrone Trieste SCpA, 34149 Trieste, Italy;Groupe Depestele, 14540 Bourguébus, France;INRA-UR1268 Biopolymers Interactions and Assemblies (BIA), CEDEX 03, BP 71627-44316 Nantes, France;Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia;University of Southern Brittany, UMR CNRS 6027, IRDL, F-56100 Lorient, France;

关键词: porosity;    internal structure;    X-ray microtomography;    scanning electron microscopy;    lumen;    flax fibre;   

DOI  :  10.3390/fib9040024

来源: DOAJ

【 摘 要 】

Plant fibres and especially flax can be distinguished from most synthetic fibres by their intricate shape and intrinsic porosity called lumen, which is usually assumed to be tubular. However, the real shape appears more complex and thus might induce stress concentrations influencing the fibre performance. This study proposes a novel representation of flax fibre lumen and its variations along the fibre, an interpretation of its origin and effect on flax fibre tensile properties. This investigation was conducted at the crossroads of complementary characterization techniques: optical and scanning electron microscopy (SEM), high-resolution X-ray microtomography (µCT) and mechanical tests at the cell-wall and fibre scale by atomic force microscopy (AFM) in Peak-Force Quantitative Nano-Mechanical property mapping (PF-QNM) mode and micromechanical tensile testing. Converging results highlight the difficulty of drawing a single geometric reference for the lumen. AFM and optical microscopy depict central cavities of different sizes and shapes. Porosity contents, varying from 0.4 to 7.2%, are estimated by high-resolution µCT. Furthermore, variations of lumen size are reported along the fibres. This intricate lumen shape might originate from the cell wall thickening and cell death but particular attention should also be paid to the effects of post mortem processes such as drying, retting and mechanical extraction of the fibre as well as sample preparation. Finally, SEM observation following tensile testing demonstrates the combined effect of geometrical inhomogeneities such as defects and intricate lumen porosity to drive the failure of the fibre.

【 授权许可】

Unknown