A study by X-ray photoelectron spectroscopy (XPS) of the chemistry of the surface of Scots pine (Pinus sylvestris L.) modified by friction

Rautkari, Lauri; Hänninen, Tuomas; Johansson, Leena‐Sisko; Hughes, Mark

doi:10.1515/hf.2011.122

Cited by 17 publications

(21 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To our knowledge, unexpectedly high amounts of CC carbon on a wood surface have been reported in all published XPS experiments on air‐exposed, dry wood materials, including our group . The data, presented here on never‐dried pine, suggests that this aging can be addressed neither to the wood material itself, nor solely to the mobile extractable molecules.…”

Section: Discussionmentioning

confidence: 59%

“…To our knowledge, unexpectedly high amounts of CC carbon on a wood surface have been reported in all published XPS experiments on air-exposed, dry wood materials, including our group. [13,14] The data, presented here on never-dried pine, suggests that this aging can be addressed neither to the wood material itself, nor solely to the mobile extractable molecules. Lignins, the other possible source of CC carbon in wood, are ruled out, too: due to their large molecular size, they have very limited mobility at or near room temperature, and they have not been observed to outgas in UHV, either.…”

Section: Discussionmentioning

confidence: 89%

See 1 more Smart Citation

XPS and the medium‐dependent surface adaptation of cellulose in wood

Johansson

Campbell

Hänninen

et al. 2012

Surface & Interface Analysis

Self Cite

View full text Add to dashboard Cite

aWe report reproducible XPS experiments on wood in two case studies. In the study on natural wood aging, we compared XPS bulk wood compositions of ancient and modern materials, analyzing spruce wood used as structural elements in roofs. Freshly cut specimens were analyzed before and after acetone extraction. In the other study, on wood surface aging, we used recently harvested, frozen pine as the sample material. In this experiment, never-dried wood surfaces were exposed to dry conditions via different routes. Combining the data presented here with our earlier studies on paper and a recent solvent-exchange study on nanofibrillated celluloses, we propose that both the lack of aging in the bulk wood and the rapid aging of the exposed wood surfaces are driven by the same process, i.e. the medium-dependent surface adaptation of nature-derived celluloses. Controlling this adaptation process is of a crucial importance in many technological applications of cellulose and wood materials.

show abstract

Section: Discussionmentioning

confidence: 59%

Section: Discussionmentioning

confidence: 89%

XPS and the medium‐dependent surface adaptation of cellulose in wood

Johansson

Campbell

Hänninen

et al. 2012

Surface & Interface Analysis

Self Cite

View full text Add to dashboard Cite

show abstract

“…The rough (un-planed) surfaces became smooth to the touch even though appearance of the surface remained uneven and rough after densification. In addition, in some cases there were yellowish spots on the rough surfaces after densification, which might be due to extractives migrating to the surface (Rautkari et al 2012). Figure 2 presents the average set-recovery values for the acetylated and un-acetylated samples.…”

Section: Densificationmentioning

confidence: 99%

Surface densification of acetylated wood

et al. 2016

Self Cite

View full text Add to dashboard Cite

The mechanical properties of wood can be improved by compressing its porous structure between heated metal plates. By adjusting the process parameters it is possible to target the densification only in the surface region of wood where the property improvements are mostly needed in applications, such as flooring. The compressed form is, however, sensitive to moisture and will recover to some extent in high humidity. In this study, therefore, acetylated radiata pine was utilised in the surface densification process in order to both reduce the set-recovery of densified wood and to improve the hardness of the acetylated wood. Pre-acetylation was found to significantly reduce the set-recovery of surface densified wood. However, after the second cycle the increase in set-recovery of acetylated wood was relatively higher than the un-acetylated wood. The acetylated samples were compressed by only 1 mm (instead of the target 2 mm), yet, the hardness and hardness recovery of the acetylated samples significantly increased as a result of densification. It was also discovered that rough (un-planed) surfaces may be surface densified, however, even if the surface became smooth to the touch, the appearance remained uneven.

show abstract

“…The interaction of several molecular probes with the highest-energy sites of the surface of the material is measured, enabling to obtain important thermodynamic and surface energy parameters. XPS gives information of the chemical composition of the surface up to approximately 10 nm depth, and it is an established method in wood science (Tuong and Li 2011 ;Brodin et al 2012 ;Rautkari et al 2012 ).…”

Section: Introductionmentioning

confidence: 99%