Surface energy characterization of thermally modified spruce using inverse gas chromatography under cyclic humidity conditions
2015 (English)In: Wood and Fiber Science, ISSN 0735-6161, Vol. 47, no 4, 410-420 p.Article in journal (Refereed) Published
The surface energy of unmodified and thermally modified spruce wood components was researched at dry and moist conditions using inverse gas chromatography. The results indicate a more pronounced heterogeneous nature of the thermally modified wood surfaces in terms of the dispersive (nonpolar) component of the surface energy, compared with that of the unmodified wood surfaces. The dispersive component of the surface energy of the thermally modified wood ranged between 44 and 38 mJ/m(2) corresponding to an increase in surface coverage from a low level and up to about 10%. Suggested explanations for the more distinct heterogeneity of the thermally modified wood sample are related to chemical changes of the wood substance which seem to result in certain micromorphological features observed by scanning electron microscopy as alternated fracture surfaces created in the grinding process; and also possible changes or redistribution of the wood extractives. An increase of the MC, representing a change from a dry condition of approximately 0% RH to ca 75% RH, of both the unmodified and thermally modified samples seemed to have a marginal influence on the dispersive component of the surface energy. Possible implications of the results in this study can be found in the tailoring of new compatible and durable material combinations, for example, when using thermally modified wood residuals as a component in new types of biocomposites.
Place, publisher, year, edition, pages
SOC WOOD SCI TECHNOL , 2015. Vol. 47, no 4, 410-420 p.
Thermally modified wood, inverse gas chromatography, humidity cycling, Norway spruce, dispersive surface energy, surface energy heterogeneity, BET-specific surface area
Research subject Civil and Architectural Engineering
IdentifiersURN: urn:nbn:se:kth:diva-172956ISI: 000363992000011OAI: oai:DiVA.org:kth-172956DiVA: diva2:851329
FunderSwedish Research Council Formas, EnWoBio 2014-172
Forskningsfinansiärer: Stiftelsen Nils och Dorthi Troëdssons forskningsfond (Projektnr 793/12 Hydro-termo-mekanisk modifiering av trä). EcoBuild Institute Excellence Centre2015-09-042015-09-032016-01-22Bibliographically approved