Penetration Pathways of Liquid Gallium in Wood Seen by Scanning Electron Microscopy
Keywords:
Scanning electron microscopy, penetration of wood, liquid gallium, <i>Pinus sylvestris</i> L, <i>Abies pectinata</i> D.C, <i>Fagus sylvatica</i> LAbstract
In order to understand and to visualize which primary pathways are followed by liquid penetration, specimens of Pinus sylvestris L., Abies pectinata D.C., and Fagus sylvatica L. were impregnated with liquid gallium at a temperature of 50 C and at varying pressures. The gallium was then solidified by cooling, and its location was observed by scanning electron microscopy on specimens previously coated with carbon to prevent redistribution of the gallium.
In softwood the liquid metal penetrated first into the longitudinal tracheids and subsequently into the rays through the cross-field-pitting. The reverse did not apparently occur, however, as radial flow through the rays was negligible. In hardwood only vessels were penetrated. For all three species, penetration uniformly increased with pressure but seemed to reach a maximum at a critical pressure level, 8 bars for pine, 16 bars for fir, and much more elevated for beech. Pit dimensions are obviously important to allow flow at low pressures and in addition, when they are large as in pine, tearing of the membrane facilitates it. Some relationships of these observations to practical aspects of wood preservation are discussed.
References
Bailey P. J., and R. D. Preston. 1969. Some aspects of softwood permeability. I. Structural studies with Douglas-fir sapwood and heartwood. Holzforschung23(4):113-120.nBailey P. J., and R. D. Preston. 1970. Some aspects of softwood permeability. II. Flow of polar and non-polar liquids through sapwood and heartwood of Douglas-fir. Holzforschung24(2):37-45.nBehr, E. A., I. B. Sachs, B. F. Kukachka, and J. O. Blew. 1969. Microscopic examination of pressure treated wood. For. Prod. J.19(8):31-40.nChoong, E. T., C. W. McMillin, and F. O. Tesoro. 1975. Effect of surface preparation on gas permeability of wood. Wood Sci.7(4):319-322.nCôté, W. A. 1963. Structural factors affecting the permeability of wood. J. Polymer Sci. part C N°2:231-242.nErickson, H. D., and J. J. Balatinecz. 1964. Liquid flow paths into wood using polymerization techniques. For. Prod. J.14(7):293-299.nHarding, F. L., and D. R. Rossington. 1970. Wetting of ceramic oxides by molten metals under ultrahigh vacuum. J. Amer. Ceramic Soc.53(2):87-90.nKlein, P., and J. Bauch. 1977. Beitrag zur Lokalisierung und quantitativen Bestimmung von Salz-Komponenten im getränkten Holz. Holzforschung31:33-40.nMack, G. L., J. K. Davies, and F. E. Bartell. 1941. La tension superficielle du Gallium. J. Phys. Chem. (45):846-850.nSchneider, A. 1979. Beitrag zur Porositätsanalyse von Holz mit dem Quecksilber-Porosimeter. Holz Roh- Werks.37(8):295-302.nSchneider, A., and L. Wagner. 1974. Bestimmung der Porengrößenverteilung Holz mit dem Quecksilber Porosimeter. Holz Roh- Werks.32(6):216-224.nSmith, D. N., and L. W. Redding. 1964. A technique for observing the penetration of preservatives into wood during treatment. Wood. September. 3 pp.nStamm, A. J. 1967a. Movement of fluids in wood. I. Flow of fluids in wood. Wood Sci. Technol.1:122-141.nStamm, A. J. 1967b. Movement of fluids in wood. II. Diffusion. Wood Sci. Technol.1:205-230.nStayton, C. L., and C. A. Hart. 1965. Determining pore size distribution in softwoods with a mercury porosimeter. For. Prod. J.15(10):435-440.nTimofeevicheva, D. A., and V. S. Lazarev. 1960. Temperature dependance of the surface tension of gallium. Reports of the Academy of Sciences USSR134(4):840-843 (Russian).nTrenard, Y. 1980. Comparaison et interprétation de courbes obtenues par porosimétrie au mercure surdiverses essences de bois. Holzforschung34(4):139-146.nVan Eyseren, J. C. 1973. Spectre de porosité du matériau ligneux. Thèse Doct. Sc. Agro. Université Catholique de Louvain. 1348 Louvain la Neuve-Belgium. 143 pp.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.
