A novel sample preparation method to avoid influence of embedding medium during nano-indentation

The effect of the embedding medium on the nano-indentation measurements of lignocellulosic materi­ als was investigated experimentally using nano-indentation. Both the reduced elastic modulus and the hardness of non­ embedded cell walls were found to be lower than those of the embedded samples, proving that the embedding medium used for specimen preparation on cellulosic material dur­ ing nano-indentation can modify cell-wall properties. This leads to structural and chemical changes in the cell-wall con­ stituents, changes that may significantly alter the material properties. Further investigation was carried out to detect the influence of different vacuum times on the cell-wall mechan­ ical properties during the embedding procedure. Interpreta­ tion of the statistical analysis revealed no linear relation­ ships between vacuum time and the mechanical properties of cell walls. The quantitative measurements confirm that low-viscosity resin has a rapid penetration rate early in the curing process. Finally, a novel sample preparation method Y. Meng · S. Wang · T.M. Young· Y. Li Center for Renewable Carbon, University of Tennessee, 2506 Jacob Drive, Knoxville, TN 37996, USA e-mail [email protected] Fax: +1-865-9461109 Y. Li e-mail [email protected] Z.Cai Forest Products Laboratory, USDA Forest Service, One Gifford Pinchot Drive, Madison, WI 53726-2398, USA G. Du Southwest Forestry University, Kunming, P.R. China Y. Li Zhejiang Agiculture and Forestry University, Zhejiang, P.R. China Published online: 25 August 2012 aimed at preventing resin diffusion into lignocellulosic cell walls was developed using a plastic film to wrap the sample before embedding. This method proved to be accessible and straightforward for many kinds of lignocellulosic material, but is especially suitable for small, soft samples.