Cell-Wall Mechanical Properties of Bamboo Investigated by In-Situ Imaging Nanoindentation
Keywords:
Bamboo fibers, cell wall, hardness, in-situ imaging nanoindentation, MOEAbstract
A novel in-situ imaging nanoindentation technique was used to investigate the cell-wall mechanical properties of bamboo fibers and parenchyma cells. In-situ imaging confirmed neither "piling up" nor "sinking in" occurred around the indentations in the cell walls. The load-displacement curves revealed different deformation mechanisms of the cell walls when indented, respectively, in the longitudinal and transverse direction of bamboo fibers. There existed significant differences in MOE between longitudinal (16.1 GPa) and transverse direction (5.91 GPa) for the cell walls of bamboo fibers, while no differences were significant in hardness. Furthermore, the measured longitudinal MOE and hardness of parenchyma cell walls were 5.8 GPa and 0.23 GPa. This corresponds to 33% and 63% of the corresponding value of bamboo fibers. It was found that the longitudinal MOE of the cells of bamboo fibers remained almost constant from the outer portion to the inner portion of bamboo culms, while hardness showed a decreasing tendency. It was concluded that the nanoindentation technique was capable of effectively characterizing the mechanical properties of bamboo at the cellular level, though it might underestimate the real longitudinal MOE of the cell walls. The results highlighted the extreme importance of locating indentations at the nano scale for the mechanical characterization of complicated natural biomaterials such as wood and bamboo.References
Amada, S., and S. Untao. 2001. Fracture properties of bamboo. Composites: Part B. 32:451-459.nBergander, A., and L. Salmén. 2000a. The transverse elastic modulus of the native wood fiber wall. J. Pulp. Pap. Sci. 26(6):234-238.nBergander, A., and L. Salmén. 2000b. Variation in transverse fiber wall properties: Relation between elastic properties and structure. Holzforschung 54(6):654-660.nCave, I. D. 1966. Theory of X-ray measurement of microfibril angle in wood. Forest Prod J. 16:37-42.nCave, I. D. 1968. The anisotropic elasticity of the plant cell wall. Wood Sci. Technol. 2(4):268-278.nCave, I. D. 1969. The longitudinal Young's modulus of Pinus radiata.Wood Sci. Technol. 3(1):40-48.nCheng, Y-T. S., and C-M. Cheng 1998. Effects of ‘sinking in’ and ‘piling up’ on estimating the contact area under load in indentation. Philosophical Magazine Letters 78(2):115-120.nGindl, W. and T. Schöberl. 2004. The significance of the elastic modulus of wood cell walls obtained from nanoindentation measurements. Composites: Part A. 35:1345-1349.nGindl, W., H. S. Gupta, and G. Grünwald. 2002. Lignification of spruce tracheids secondary cell wall related to longitudinal hardness and modulus of elasticity using nano-indentation. Can. J. Bot. 80:1029-1033.nHabelitz, S., S. J. Marshall, G. W. Marshall, and M. Balooch. 2001. Mechanical properties of human dental enamel on the nanometer scale. Archives Oral Biol. 46: 173-183.nHuang, S. X., L. N. Ma, Z. P. Shao, and X. H. Zhou. 2005. Relationship between microstructure characteristics and mechanical properties of Moso bamboo. J. Anhui Agric. Univ. 32(2):203-206.nJiang, Z. H., Y. Yu, B. H. Fei., H. Q. Ren., and T. H. Zhang. 2004. Using nanoindentation technique to determine the elastic modulus and hardness of trachedis secondary wall. Scientia Silvae Sinicae (in Chinese). 40(2): 113-118.nOliver, W. C., and G. M. Pharr. 1992. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Rec. 7(6):114-117.nPage, D. H., F. El-Hosseiny, K. Winkler, and A. P. S. Lancaster. 1977. Elastic modulus of single wood pulp fibers. Tappi 60(4):114-117.nRho J. Y., and G. M. Pharr. 1999. Effects of drying on the mechanical properties of bovine femur measured by nanoindentation. J. Mater. Sci: Materials in Medicine. 10:485-488.nSwadener, J. G., J. Y. Rho, and G. M. Pharr. 2001. Effects of anisotropy on elastic moduli measured by nanoindentation in human tibial cortical bone. J. Biomed. Mater. Res. 57:108-12.nTakagi, H., R. Takura, Y. Ichihara, S. Ochi, H. Misawa, and R. Niki. 2003. The mechanical properties of bamboo fibers prepared by steam-explosion method. J. Soc. Mater. Sci., Japan. 52(4):353-356.nTommy, Y Lo., H. Z. Cui, and H. C. Leung. 2004. The effect of fiber density on strength capacity of bamboo. Materials Letters 58:2595-2598.nTurner, C. H., J. Rho, Y. Takano, T. Y. Tsui, and G. M. Pharr. 1999. The elastic properties of trabecular and cortical bone issues are similar: results from two microscopic measurement techniques. J. Biomechanics 32: 437-441.nWang, Z. H. 2001. Study on variation pattern of bamboo properties and its correlation to industrial utilization. Ph.D dissertation (in Chinese). The Chinese Academy of Forestry, Beijing, China. Pp. 146-148.nWimmer R. and N. Lucas. 1997. Comparing mechanical properties of secondary wall and cell corner middle lamella in spruce wood. IAWA. 18(1):77-88.nWimmer R. N. Lucas., T. Y. Tsui, and W. C. Oliver. 1997. Longitudinal hardness and Young's modulus of spruce tracheid secondary walls using nanoindentation technique. Wood Sci. Technol. 31(2):131-141.nYu, Y. 2003. Longitudinal mechanical properties and its main influencing factors of tracheids of Chinese fir from plantation. Ph.D dissertation (in Chinese). The Chinese Academy of Forestry, Beijing, China.n
Downloads
Published
Issue
Section
License
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.
