Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Feb 20;14(1):4168.
doi: 10.1038/s41598-024-54451-9.

Effects of sepiolite addition to acrylic-latex paint on pull-off adhesion strength in nanosilver-impregnated and thermally-modified beech (Fagus orientalis L.) wood

Hamid R Taghiyari  1 , Petar Antov  2 , Abolfazl Soltani  3 , Dorina Camelia Ilies  4 , Elham Nadali  5 , Seng Hua Lee  6   7 , Vasile Grama  8 , Tripa Simona  9
Affiliations

Effects of sepiolite addition to acrylic-latex paint on pull-off adhesion strength in nanosilver-impregnated and thermally-modified beech (Fagus orientalis L.) wood

Hamid R Taghiyari et al. Sci Rep. .

Abstract

Sepiolite is a silicate mineral that improves the fire properties in solid wood when mixed with a water-based coating. The present study was carried out to investigate and evaluate the effects of sepiolite addition to acrylic-latex paint on the pull-off adhesion strength, as an important characteristic of paints and finishes used in the modern furniture industry and historical furniture as well for preservation and restoration of heritage objects. Sepiolite was added at the rate of 10%, and brushed onto plain-sawn beech (Fagus orientalis L.) wood specimens, unimpregnated and impregnated with a 400 ppm silver nano-suspension, which were further thermally modified at 185 °C for 4 h. The results showed that thermal modification had a decreasing effect on the pull-off adhesion strength, primarily as a result of the thermal degradation of cell-wall polymers (mostly hemicelluloses). Still, a decreased wettability as a result of condensation and plasticization of lignin was also partially influential. Based on the obtained results,thermal modification was found to have a significant influence on pull-off adhesion strength. Sepiolite addition had a decreasing effectin all treatments, though the effect was not statistically significant in all treatments. The maximum and minimum decreases due to sepiolite addition were observed in the unimpregnated control (21%) and the thermally-modified NS-impregnated (4%) specimens. Other aspects of the sepiolite addition, and further studies that cover different types of paints and coatings, should be evaluated before coming to a final firm conclusion in this regard.

Keywords: Coating and finish; Paint pull-off strength; Porous structure; Sepiolite; Silver nano-suspension; Thermal modification.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Schematic diagram of the plain-sawn specimens showing two dollies stuck on the upper surface.
Figure 2
Figure 2
Photos showing microfibers in sepiolite (a and b).
Figure 3
Figure 3
Photomicrograph of sepiolite microfibers taken by polarized microscope (cross-polarized light XPL, × 72).
Figure 4
Figure 4
SEM image of sepiolite microfibers.
Figure 5
Figure 5
Schematic design of the dolly to be stuck to the plain-sawn beech wood substrate; (A) dolly with an effective surface diameter of 20 mm, (B) dolly stuck to the plain-sawn wood specimen.
Figure 6
Figure 6
Pull-off specimen of the control beech substrate showing remnants of the adhesive portions where the adhesive layer is visible in the probably irregular areas of the specimen (left image ↓), and the aluminum surface of tested dolly demonstrating that the failure partially occurred in the adhesive layer (right image ↓) (magnification × 2.5).
Figure 7
Figure 7
Pull-off specimen of the thermally-modified beech substrate illustrating full and accepted failure in the body of the wood substrate (no failure occurred in the adhesive layer) (magnification × 2.5).
Figure 8
Figure 8
Pull-off adhesion values (MPa) of plain-sawn beech specimens, painted with an acrylic-latex paint (P painted, NSI nanosilver-impregnated, TM thermally-modified specimens). Error bars represent the standard deviation; letters on each column represent Duncan's multiple range groupings based on a 95% level of confidence.
Figure 9
Figure 9
Pull-off adhesion values (MPa) of plain-sawn beech specimens, without any finish or paint (NS nanosilver). Error bars represent the standard deviation; letters on each column represent Duncan's multiple range groupings based on a 95% level of confidence.
Figure 10
Figure 10
SEM images (a–c) showing the vessel elements and fiber cavities (↓) with different magnitudes in the plain-sawn beech wood.
See this image and copyright information in PMC

References

    1. Ekstedt, J. Studies on the Barrier Properties of Exterior Wood Coatings 75, Dissertation, KTH Royal Institute of Technology, Department of Civil and Architectural Engineering, Division of Building Materials (2002).
    1. Jirouš-Rajkovic V, Miklecic J. Enhancing weathering resistance of wood: A review. Polymers. 2021;13:1980. doi: 10.3390/polym13121980. - DOI - PMC - PubMed
    1. Bekhta P, Krystofiak T, Lis B, Bekhta N. The impact of sanding and thermal compression of wood, varnish type and artificial aging in indoor conditions on the varnished surface color. Forests. 2022;13(2):300. doi: 10.3390/f13020300. - DOI
    1. Kačík F, Kubovský I, Bouček J, Hrčka R, Gaff M, Kačíková D. Colour and chemical changes of black locust wood during heat treatment. Forests. 2023;14(1):73. doi: 10.3390/f14010073. - DOI
    1. Hill CAS. Wood Modification—Chemical, Thermal and Other Processes. Wiley; 2006.