title: Evaluation of elastic modulus and hardness of crop stalks cell walls by nano-indentation.
abstract: Agricultural biomaterials such as crop stalks are natural sources of cellulosic fiber and have great potential as reinforced materials in bio-composites. In order to evaluate their potential as materials for reinforcement, the nano-mechanical properties of crop-stalk cell walls, i.e. those of cotton (Gossypium herbaceu) stalk, soybean (Glycine max) stalk, cassava (Manihot esculent) stalk, rice (Oryza sativa L.) straw, and wheat (Triticum aestivum L.) straw, were investigated by means of nano-indentation and atomic force microscopy (AFM). The elastic modulus of wheat straw was found to be 20.8 GPa, which was higher than that of the other four crops. The highest hardness was observed in cotton stalk at 0.85 GPa. The elastic moduli of the crop stalks were lower than those of most of the hardwood species, but higher than that of some softwoods and of lyocell fiber. The mean value of the hardness of the five crop stalks' cell walls was higher than those of wood or lyocell fiber.
authors: College of Wood Science and Technology, Nanjing Forestry University, Nanjing 210037, PR China.
authors: Yan
authors: Y
authors: Wu
authors: Siqun
authors: S
authors: Wang
authors: Dingguo
authors: D
authors: Zhou
authors: Cheng
authors: C
authors: Xing
authors: Yang
authors: Y
authors: Zhang
authors: Zhiyong
authors: Z
authors: Cai
mesh_terms: D002473:Cell Wall / Q000502:physiology*; D018556:Crops, Agricultural / Q000033:anatomy & histology / Q000502:physiology*; D055119:Elastic Modulus; D006244:Hardness; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods; D018547:Plant Stems / Q000166:cytology*