Cell wall microstructure, pore size distribution and absolute density of hemp shiv: Microstructure, porosity and absolute density

Yunhong Jiang, Robert Lawrence, Martin Ansell, Atif Hussain

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

This paper, for the first time, fully characterizes the intrinsic physical parameters of hemp shiv including cell wall microstructure, pore size distribution and absolute density. Scanning electron microscopy revealed microstructural features similar to hardwoods. Confocal microscopy revealed three major layers in the cell wall: middle lamella, primary cell wall and secondary cell wall. Computed tomography improved the visualization of pore shape and pore connectivity in three dimensions. Mercury intrusion porosimetry (MIP) showed that the average accessible porosity was 76.67 ± 2.03% and pore size classes could be distinguished into micropores (3–10 nm) and macropores (0.1–1 µm and 20–80 µm). The absolute density was evaluated by helium pycnometry, MIP and Archimedes’ methods. The results show that these methods can lead to misinterpretation of absolute density. The MIP method showed a realistic absolute density (1.45 g cm −3) consistent with the density of the known constituents, including lignin, cellulose and hemi-cellulose. However, helium pycnometry and Archimedes’ methods gave falsely low values owing to 10% of the volume being inaccessible pores, which require sample pretreatment in order to be filled by liquid or gas. This indicates that the determination of the cell wall density is strongly dependent on sample geometry and preparation.

Original languageEnglish
Article number171945
Pages (from-to)1-15
Number of pages15
JournalRoyal Society Open Science
Volume5
Issue number4
DOIs
Publication statusPublished - 4 Apr 2018

Keywords

  • Hemp shiv
  • Microstructure
  • Porosity
  • Absolute density
  • Mercury intrusion porosimetry
  • Helium pycnometry

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)

Fingerprint Dive into the research topics of 'Cell wall microstructure, pore size distribution and absolute density of hemp shiv: Microstructure, porosity and absolute density'. Together they form a unique fingerprint.

  • Projects

  • Profiles

    No photo of Michael Lawrence

    Michael Lawrence

    Person: Honorary / Visiting Staff

    Cite this