The objective of this study was to investigate the surface free energy of poplar and yellow pine strands by Wilhelmy Plate Method. The measurement items included the surface contact angle, surface free energy and chan...The objective of this study was to investigate the surface free energy of poplar and yellow pine strands by Wilhelmy Plate Method. The measurement items included the surface contact angle, surface free energy and change of sample weight. Thirty industrial strands were randomly collected for each condition. The samples were cut down to 25.0-26.0 mm long, 7.0-8.0 mm wide. The density and thickness of each sample were also tested. The range of density was from 0.35 to 0.75 g/cm^3 and the range of thickness was from 0.5 to 1.0 ram. The research result shows that there is a close relationship between the wettability, mass change and moisture content. Both the density and the thickness of the strand have a small influence on the surface contact angle and the surface free energy.展开更多
Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth...Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth and load are recorded so that stiffness and hardness of the indented location can be subsequently calculated. The micron spatial resolution in nanoindentaion tests renders the technique very useful in the investigation of the wood cell-wall level and polymer interphase. This review mainly discussed the principle of nanoindentation and its current applications in wood science field.展开更多
基金This study is supported by the project of natural science basic research in Jiangsu universities under Contact Number 05KJA22019,namely research on the properties modification of fast-growing poplar wood.
文摘The objective of this study was to investigate the surface free energy of poplar and yellow pine strands by Wilhelmy Plate Method. The measurement items included the surface contact angle, surface free energy and change of sample weight. Thirty industrial strands were randomly collected for each condition. The samples were cut down to 25.0-26.0 mm long, 7.0-8.0 mm wide. The density and thickness of each sample were also tested. The range of density was from 0.35 to 0.75 g/cm^3 and the range of thickness was from 0.5 to 1.0 ram. The research result shows that there is a close relationship between the wettability, mass change and moisture content. Both the density and the thickness of the strand have a small influence on the surface contact angle and the surface free energy.
文摘Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth and load are recorded so that stiffness and hardness of the indented location can be subsequently calculated. The micron spatial resolution in nanoindentaion tests renders the technique very useful in the investigation of the wood cell-wall level and polymer interphase. This review mainly discussed the principle of nanoindentation and its current applications in wood science field.
