DCSBD Plasma Treatment as an Alternative to Commercial Surface Degreasing Agents Before Applying Wood Coatings

DCSBD Plasma Treatment as an Alternative to Commercial Surface Degreasing Agents Before Applying Wood Coatings | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article DCSBD Plasma Treatment as an Alternative to Commercial Surface Degreasing Agents Before Applying Wood Coatings Neja Bizjak Štrus, Zlata Kelar Tučeková, Dávid Brodňanský, Jakub Kelar, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7259572/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 19 Apr, 2026 Read the published version in Cellulose → Version 1 posted 4 You are reading this latest preprint version Abstract In recent years, research has focused on eco-friendly techniques to find alternatives to traditional methods to reduce environmental impact. This paper examines three wood degreasing methods and their impact on two different wood coatings. Conventionally used turpentine and petroleum-based solvents were compared with diffuse coplanar surface barrier discharge plasma treatment for degreasing soft and hardwoods. The effect of plasma degreasing technique was tested on an antifouling paint (both with and without epoxy primer) and on a polyurethane varnish made from a modified alkyd resin. To evaluate degreasing methods on varnishes over time, accelerated artificial ageing was conducted for 240 hours. Gloss, colour, and ATR FT-IR measurements were taken for evaluation. All samples showed darkening and a loss of gloss after undergoing artificial weathering, with the most significant colour changes observed within the first 120 hours. ATR FT-IR analysis indicated no significant differences in the coatings based on the degreasing method used. This confirms that plasma degreasing is just as effective as traditional methods and does not notably affect the appearance of the coating. DCSBD plasma degreasing wood coatings artificial ageing Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction The use of wood in a variety of sectors and applications is steadily growing, with softwoods being predominant, e.g. in the construction industries (Klein and Grabner 2015 ) and hardwoods being predominant, e.g. in the furniture sector (Teischinger 2017 ). While some wood species exhibit a natural resistance to decay in outdoor conditions, most wood materials have to be protected from weathering, including through constructive measures, impregnation and coating. Most challenging environments are those of constant water contact, such as wood in ground contact (Wakeling and Morris 2014 ) or in marine environments (Arango et al. 2010 ). Corresponding demands are particularly elevated in high-value added products, as is the case, e.g. for the wooden decking on boats and yachts, as the weathering conditions are specifically harsh and expectations for aesthetics and longevity are particularly high. Traditionally, tropical hardwoods would have been used for the decking due to their decay resistance, whereas durable hardwoods like oak were less preferred. However typical softwoods were valued for their good mechanical properties at low weight, more specifically, spruce was commonly used for spars, whereas pine was recommended for planking due to its high pitch content (Hillman 1956 ). More recently, however, tropical hardwoods and other exotic woods have become unfavourable due to their environmental impact and deforestation. Instead, polymers and composites have strongly gained in importance over teak and other tropical hardwoods (Pittaway 2023 ; Tucker 2022 ). Even more recommendable, are locally grown wood varieties to ensure sustainability, high environmental standards and ecodesign (Pommier et al. 2016 ). However, to make such wood species viable, coatings with superb performance are essential. In a recent study, Scots pine was found as the most durable local wood species for decking application with a 45- and 150-times longer estimated service life than the most abundant local wood species, beech and Norway spruce, respectively (Brischke et al. 2017 ). The surface protection by a suitable coating system is essential for such locally grown wood varieties to be utilised in such demanding applications as decking (Humar et al. 2019 ). Typical coating systems in such applications may employ epoxy or acrylic polymer systems as basis for the formulation (Bulian and Graystone 2009 ). A crucial step in ensuring high durability and performance of the coatings, wooden surfaces need to be properly prepared in the ways indicated by the manufacturers for commercial coating systems, as deviations regularly lead to early delamination and failure (Brooke et al. 2025 ). Several manufacturers of coatings intended for boat decking prescribe the need for “degreasing”, i.e. scrubbing the surface with alcohol or nitro solvents – usually this is prescribed for wood species with high resin contents (Allen 2006 ), whereas some manufacturers recommend degreasing for all surfaces regardless of the wood species. For high-performance wooden decking, impregnation is another treatment step adding to a significantly increased service life. Here, typical agents deposited into the bulk of the wooden parts are chromated copper arsenate or copper azole (McFarling and Morris 2005 ; Schauwecker et al. 2009 ). Plasma discharges are an environmentally friendly technology used in many sectors for degreasing, thereby effectively replacing solvent-based processing steps (Klingner et al. 2013 ; Krüger et al. 1999 ; Primc and Mozetič 2019 ). Non-thermal plasmas (NTP) have been utilised on wood surfaces for a variety of purposes, including for increasing adhesion and performance of coating systems and adhesive joints (Acda et al. 2012 ; Dahle et al. 2021 ; Petrič 2013 ). Most commonly, air is used as the process gas for NTP treatments at atmospheric pressure, as the most accessible and cost-effective variety of plasma treatments for wooden work pieces (Žigon et al. 2018 ). The effects of NTP treatments on wood have been demonstrated to modify the wood surfaces chemically (Lux et al. 2013 ; Rehn and Viöl 2003 ), including the generation of polar groups on lignin and the modification of cellulose (Klarhöfer et al. 2010 ) and the removal of extractives and volatile organic compounds from the surface-near parts of the wood (Avramidis et al. 2012 ), as well as being able to modify the wood surface morphologically through etching upon prolonged treatments (Jamali and Evans 2011 ). Dielectric barrier discharge (DBD) plasmas represent a well-scalable NTP technology that operates at low temperatures, thereby minimising energy losses (Kogelschatz 2004 ). In contrast to plasma jets, such discharges can be applied on larger areas and exclude the need for scanning that narrow jets typically impose (Žigon et al. 2018 ). In particular, the most easily scalable variety of DBD plasmas is the diffuse coplanar surface barrier discharge (DCSBD) (Odrášková et al. 2008 ), which provides the additional benefit of being largely independent of the material and thickness of the work piece to be treated, but requires a certain flatness to be applicable on a work piece (Talviste et al. 2020 ). On wood substrates, DCSBD has been demonstrated to chemically activate surfaces of different wood species, thereby improving its wettability (Jablonský et al. 2016 ). With that, DCSBD appears most applicable and promising for applications, especially intended for cladding and decking applications. In this study, we investigated the use of DCSBD plasma treatments replacing conventionally prescribed solvent-based degreasing prior to deposition of coatings for boat decking. Substrates included European red pine as a common, locally grown boat decking material, as well as Norway spruce and European beech as the most abundant locally grown wood species. Two different commercial coating systems were used, thereby covering epoxy- and acrylic-based formulations. The performance of the sample systems was investigated using artificially accelerated weathering (AW), combined with the analysis of gloss, colour and chemical changes. For the experiment, we also conducted a preliminary life cycle analysis and cost analysis (Bizjak Štrus et al. 2025). 2. Materials and Methods 2.1. Wood degreasing Boards made of European beech ( Fagus sylvatica L.), European red pine ( Pinus sylvestris L.), and Norway spruce ( Picea abies (L.) Karst.) with dimensions 70×30×5 mm 3 and radial orientation of the fibres were used for the experiment. The surface was planed flat without any additional sanding. Samples were conditioned to natural conditions of 20 °C and 65 % relative humidity, corresponding to a wood moisture content of 10-12 %. Samples were degreased with DCSBD plasma, turpentine (Terpentinovo olje, Chemcolor Sevnica d.o.o., Blanca, Slovenia) or a commercial petroleum-based solvent (AMAL 1030 razrdečilo, AMAL d.o.o., Ljubljana, Slovenia) (AMAL1030), respectively. Turpentine and AMAL1030 were applied with a paper towel. A DCSBD plasma (CEPLANT, Brno, Czech Republic) degreasing process was optimised based on water contact angle measurements (see below) to improve efficiency, including adjusting the plasma treatment duration and the electrode's distance from the board's surface. As a result of the optimisation process, specimens were treated for 10 s with an input power of 400 W at a distance of 0.5 mm from the DCSBD plasma unit, thereby accommodating for minute deformations (cupping, warping) of the specimens, while also taking into account previously published data (Talviste et al. 2019). 2.2. Wood degreasing 2.2.1. Diffuse coplanar surface barrier discharge (DCSBD) plasma device The system of DCSBD plasma consists of parallel silver electrodes embedded in 96 % aluminium using a multilayering lamination technique, as was described in detail before (Černák et al. 2009). This device operates at high-frequency high-voltage of approx. 15 kHz with peak-to-peak voltages of 10 – 20 kV. Such configuration provides macroscopically homogeneous plasma in ambient air at atmospheric pressure. The generated plasma layer has an estimated effective thickness of approx. 0.3 mm, depending on the generating conditions, such as gas composition or input power (Šimor et al. 2002). In our experiments, we used the distance between the wood surface and the ceramic surface of 0.5 mm due to the possible unevenness of the wood. The effect of plasma in this distance was tested prior to the rest of the experiments and was deemed satisfactory. The mass loss determined by weighing before and after degreasing amounted to 0.2 % or less of the specimens’ masses and was thus found to be insignificant. 2.3. Water contact angle measurements (WCA) The water contact angles were measured with deionised water after degreasing for all three above-mentioned methods using the optical goniometer. WCA was evaluated by Young–Laplace analysis using the software. In total, 7 – 13 droplets for different parameters were analysed, and each droplet was measured for 63 s (1.9 images per second). The measurement of the WCA started approximately 2 s after the first contact of the drop with the sample surface. The measurements began right after the degreasing method was applied to prevent the measured values from being affected by ageing. 2.4. Wood coating After degreasing, the samples were coated. Samples that were cleaned with AMAL1030 and one-third of plasma-cleaned samples were coated with an alkyd-based clear varnish (Lak za čolne, AMAL d.o.o., Ljubljana, Slovenia) (AMAL) and applied in two layers. Half of the turpentine-cleaned boards and one-third of the plasma-treated wood were primed with epoxy-based primer (Curing agent 95360 and light primer 45559, HEMPEL d.o.o., Umag, Croatia) and then coated with two layers of antifouling paint (Hard Racing white 76300, HEMPEL d.o.o., Umag, Croatia) (HR), while the remaining cleaned samples were just coated with two layers of HR (without primer). The varnishes and primer were applied as per the manufacturer's instructions. 2.5. Artificial weathering (AW) The artificial ageing chamber, according to the standard EN ISO 11341:2004 in the interior mode, was used for AW. Degreased and varnished samples underwent 240 hours of AW. They were loaded on the tray with a spacing of around 1 cm between them. The xenon-arc lamp was used in the AW chamber with a 3-mm window glass filter to produce spectra equivalent to sunlight coming through the window glass (McGreer 2001). The lamp’s parameters and the conditions in the chamber during the AW test were as follows: irradiance control was set to 340 nm, the cycle to 102/18, the irradiance power to 0.35 W/m 2 , the chamber air temperature to 38 °C, the black standard temperature to 68 °C, and the relative air humidity to 68 %. Water was introduced in the form of spray, and filter daylight was selected. The cycle was interrupted twice for gloss and colour measurements. After AW, the samples were removed from the chamber for further work and analysis. 2.6. Gloss and colour measurements Gloss and colour were measured before AW, after 72 and 120 hours and at the end of AW. Gloss was measured following the SIST EN ISO 2813:1999 standard using a gloss meter. Measurements were taken on each sample at three locations: one in the middle and two near opposite edges. The measurements were taken at a 60° angle of the incident light, parallel to the board fibres in the longitudinal direction. Areas with natural discolouration or cramps were avoided. The colour was measured following the standard ISO/DIS 7724-2:1997 using a spectrophotometer with a standard D65 light source. The CIELAB parameters ( L* , a* , and b* ), their changes (Δ L* , Δ a*, and Δ b* ), and the total colour change (Δ E* ) were determined with the CIEDE2000 formula (Sharma et al. 2005), using Eq. (1). Eq. (1) The L* parameter ranges from 0 to 100, where 0 represents total darkness, and 100 represents maximum lightness. It is calculated based on the relative luminance of a sample colour, derived from the tristimulus values that represent the colour's response to light under a standard light source. Parameter L* is represented on the polar axis in the three-dimensional colour space (Durmus 2020). The a* parameter ranges between -300 and 220, where positive values indicate redness and negative greenness. Parameter b * ranges between -200 and 160; positive values indicate yellowness, and negative b* values indicate blueness. Both parameters are calculated based on the relative luminance of a sample colour, derived from the tristimulus values that represent the colour's response to light under a standard light source (Durmus 2020). In addition to these separate parameters, a total colour change can be calculated using Eq. (1), which considers all measured parameters. Measurement areas were in the middle and on the opposite edges of the sample, totalling three measurements per board. Natural discolouration areas or cramps were avoided. For reference, one specimen per sample system (substrate material × degreasing technique × coating type) was stored in the dark. 2.7. Attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy ATR FT-IR spectroscopic measurements of the control and aged wood surfaces were performed using an ATR FT-IR spectrometer with a LiTaO 3 detector type in the absorbance mode. The spectra were corrected for background, and 16 scans per sample were collected at a wavelength from 400 to 4000 cm −1 at a resolution of 0.5 cm −1 . Spectra were interpreted later using the software. Measurements were taken after each layer of varnish, along with measurements of the coating on glass to serve as a background. 3. Results with Discussion 3.1. Water contact angle After testing different plasma settings, the optimal parameter with a low WCA and treatment time was selected. Contact angles are represented in Table 1. Almost all methods of degreasing reduced the WCA, with the most significant decrease observed in the beech and pine wood treated with plasma. There were statistically significant differences in WCA between all methods, except for pine boards that were untreated and treated with AMAL1030, as well as between AMAL1030-treated and plasma-treated spruce boards. When comparing turpentine and AMAL1030, turpentine showed a higher decrease of WCA in all wood species. Table 1 Mean and standard error of water contact angle (WCA) after different degreasing methods. Highlighted values represent the statistical insignificance of WCA between treatments within the wood type. Treatment Pine [°] Beech [°] Spruce [°] mean SE mean SE mean SE Untreated 80.4 5.05 69.8 0.90 51.6 4.07 DCSBD plasma 14.4 2.22 5.92 0.63 34.9 3.20 Turpentine 49.4 4.72 31.7 1.93 24.8 1.68 AMAL1030 79.4 2.13 52.9 2.08 42.8 2.16 3.2. Gloss In all three tested wood species, the highest gloss was observed in wood varnished with AMAL, and the most changes in gloss were noticed after 72 hours of AW. The HR fully coated the wood, so the wood colour was not visible and could not affect the varnish gloss. The gloss of the HR depended solely on the varnish itself, whereas the gloss of AMAL could be affected by the underlying wood colour. At the beginning of the experiment, beech wood with AMAL varnish had the highest gloss level. This is likely due to the higher density of beechwood, which contributes to a smoother surface finish. The density was calculated based on the samples' volume and mass, showing that beech wood (665 kg/m 3 ) is denser than spruce (435 kg/m 3 ) or pine wood (634 kg/m 3 ). This higher density may enhance light reflectivity and contribute to a glossier finish. Moreover, the hardwood has more porosity and varnish can penetrate into the wood, fill the micropores, and result in a smoother surface with higher gloss (Plötze and Niemz 2011). However, after exposure to AW, the AMAL beech wood experienced a greater loss of gloss after 72 h of AW than the other two wood types (Δt 1 = gloss before AW – gloss after 72 hours of AW). When comparing different types of wood, it was observed that beechwood coated with AMAL exhibited the highest level of gloss change after the first three days of AW types compared to spruce and pine wood (beech Δt 1 = 41.3 GU, spruce Δt 1 = 14.3 GU, pine Δt 1 = 21.7 GU). The final comparison is between degreasing with turpentine and plasma, as well as AMAL1030 and plasma. The t-test revealed no statistically significant difference before AW between plasma and turpentine-treated wood with HR and no difference between plasma and AMAL1030 for AMAL varnish. A statistically significant difference after AW was found between plasma and AMAL1030 degreasing and coated with AMAL for all three wood species. Plasma-treated spruce wood lost more gloss compared to AMAL1030, whereas plasma-degreased pinewood and beechwood lost less gloss compared to AMAL1030. The gloss of coated samples during AW is shown in Fig.3 together with values of dark reference for each treatment. 3.3. Colour 3.3.1. Parameter L* When comparing colour, AMAL and HR cannot be compared because the wood's colour influences the AMAL's colour. In contrast, the HR is white, but primed samples can appear greyer. Both provide good coverage. AW lowered the L* parameter for all wood species, causing the varnish to darken after exposure to UV radiation and moisture. This was confirmed with a one-way ANOVA test with an additional Student’s Post Hoc test for values within treatment. After AW, lightness of pine and spruce wood degreased with plasma did not differ from turpentine or AMAL1030 degreased samples. In beechwood, samples degreased with plasma or turpentine and then coated with primer and HR showed no difference in the L* parameter after AW. However, unprimed HR samples and AMAL coated samples indicated a statistically significant difference in lightness between plasma and turpentine or AMAL1030 degreased samples. In both scenarios, plasma-degreased samples exhibited a lower L* parameter. Some measurements showed a statistically significant difference of L* before AW, but there was no difference at the end of AW. Some intermediate measurements indicated statistically significant differences but did not consistently translate into final significant differences between treatments. Parameters a* and b* Inside all treatments with AMAL, one-way ANOVA with Students’ Post Hoc test confirmed wood colour shifted towards yellow (change in b* parameter), which can be addressed to the yellowing of polyurethane-based varnishes (Rossi et al. 2016; Rosu et al. 2009), as well as lignin and holocellulose degradation (Geffertová et al. 2018). This is especially true for spruce and pinewood. In HR coated samples (primed and unprimed), there is less change in b* parameter. In HR-coated wood, there is not much difference in the a* parameter after AW, but there is a significant difference in AMAL-coated wood. When pine and spruce are treated with AMAL, the a* parameter value indicates that the wood becomes redder. However, this does not hold true for beechwood. Initially, it may show this trend, but then it changes, and ultimately, the wood shows more greenness. Redness might be due to the accumulation of phenols and flavonoids present in conifers (Kozłowska et al. 2007). 3.3.2. Colour change ΔE The colour change was evaluated as a mean colour change compared to the colour before AW. A graphical representation of colour change can be seen in Fig.2. The greatest change can be observed in wood coated with AMAL varnish. The most significant changes occured after 120 hours of AW. The colour change is important information because it reflects the colour change, not just individual parameters (Geffertová et al. 2018). Before the AW, the colour on all boards was intact. The observation of the samples revealed a colour change. After 72 hours of AW, noticeable changes occurred, particularly in the samples that did not have primer before applying the HR. The absence of primer resulted in cracking and peeling of the colour from all tested wood species, with beechwood being the most affected. Some noticeable cracks were also present in the primed samples, appearing at the edges of the boards. All boards appeared darker, especially AMAL coated samples. After 120 hours of AW, samples without primer showed more cracks, and the coating started to peel off, particularly from the beechwood. The cracks in the primed samples did not progress as much as those in the unprimed samples. The colour became darker for all samples with HR coating, and the edges turned yellow. Samples with an AMAL varnish became darker, and some of them acquired a dark grey colour on the edge. During the AW, samples without primer were significantly damaged, with more than half of the coating peeling off in some cases. Samples with primer showed increased cracking at the edges, and the coating developed yellow patches of discolouration. AMAL varnished pine and spruce samples appeared redder. AMAL varnish on beechwood samples was washed away, which affected the wood underneath, resulting in greyish patches. Additionally, the edges appeared greyish. A few examples of AW samples and dark reference samples can be observed in Fig.3. The remaining coating from unprimed samples coated with HR was measured, and the data is represented in Table 2. The statistical analysis did not show a difference in peeled coating between plasma and turpentine-degreased samples. Between 13% and 56% of the coating peeled from beech samples after ten days of AW regardless of degreasing technique. Table 2 Average area of remaining coating after ten days of artificial ageing of beech wood (B), spruce wood (S), pine wood (P), coated with antifouling paint without primer. T-test (TT) was performed to compare turpentine (T) and plasma (P) degreased samples. sample area [cm 2 ] area [%] P (TT) B_T 16.2 77.2 > 0.05 B_P 9.2 44.0 S_T 18.3 87.1 > 0.05 S_P 18.0 85.6 P_T 17.8 84.8 > 0.05 P_P 16.2 77.2 3.4. ATR FT-IR spectra Spectra are divided into two regions: fingerprint and non-fingerprint region. The fingerprint region is set to be between 600 and 1400 cm -1 , where most of the complex vibrations are found. The non-fingerprint region is between 1600 and 3500 cm -1 and contains simple stretching vibrations. These peaks are the most characteristic and reliable (Wade 2013). At first, untreated and degreased samples, as well as both varnishes and primer, were analysed. Fig.4 a-c shows spectra of untreated and degreased samples. The degreased samples were expected to show some changes indicating the previous presence of fatty acids. Fatty acids contain a carboxyl functional group, so we would anticipate O-H, C=O and C-H stretches (Kim et al. 2019). Lower absorption of spruce and pine at around 2900 cm -1 can be observed, which correlates with C-H stretching at CH x structures (Odrášková et al. 2008). This could be associated with the degradation of lignin, cellulose, extractives or fatty acids. Also, carboxyl groups and alkane bonds are naturally present in wood (Md Salim et al. 2021), so wood’s functional groups could mask the lack of fatty acid. Additionally, in Fig.4 a, a change in absorption at the peak of 2360 cm-1 can be observed for AMAL1030 and turpentine degreasing method. This spectrum indicates carbon dioxide originating from the atmosphere. Afterwards, coated samples were analysed. Fig.4 d-f shows the spectrums after applying the first layer of AMAL, primer or the first layer HR. Some peaks are slightly deformed and have different intensities. However, it can still be determined that there is no difference between wood types or plasma and degreasing treatments, regardless of treatment. AMAL, HR and primer coated on glass were also analysed, serving as a reference, and can be observed in the top spectrum of Fig.4 d-f. The thickness of a single coating layer is approximately 90 µm (manufacturer's information on the technical sheet), while the ATR FT-IR's penetration depth is 0.5 – 2 µm (Liu et al. 2022). Analysing primer and HR were trickier because there were more listed ingredients and more peaks in spectra. Primer is a mixture of epoxy base and curing agents, each with different ingredients. The first primer peaks are at 3550 and 3320 cm -1 and belong to O-H and N-H stretching. Next is the dual peak at 2925 and 2850 cm -1 , which belongs to C-H stretching. Alkenes from petroleum can be observed at 1650 cm -1 as C=C stretch and 1600 cm -1 as conjugated alkene. Peak 1243 cm -1 can be from an alkyl aryl ether bridge in epoxy resin as the main ingredient of the primer base. Primer peaks can be observed in Fig.4 e. The HR spectrum (Fig.4 f) first shows a broad peak at 3390 cm -1 , representing an O-H stretch from 2,5-di-tert-butylhydroquinone. It is followed by a dual peak at 2925 and 2870 cm -1 , which belongs to C-H stretching, mainly from petroleum. The peak at 2160 cm -1 is not as common and belongs to the stretching of S-C≡N from copper thiocyanate. 1730 cm -1 is a ketone stretch of C=O from 4-methyl pentane-2-one. A peak at 1585 cm -1 probably belongs to the carbon double bond stretch from xylene and 2,5-di-tert-butylhydroquinone. Double peaks at 1464 and 1410 cm -1 are typically associated with the bending vibrations of C-H bonds in methylene (-CH 2 -) petroleum groups. 4. Conclusion In this experiment, we compared the DCSBD plasma degreasing method with turpentine and petroleum-based solvents on hardwood (beech) and two softwood species (pine and spruce). Additionally, we investigated how this degreasing method affects varnish application. We tested two types of varnishes, the first was AMAL, a polyurethane varnish based on modified alkyd resin, and the second was HR antifouling paint, which was applied both with and without an epoxy primer. All samples experienced gloss loss during AW. AW also reduced the value of the L* parameter for all samples due to varnish darkening after exposure to UV radiation and moisture. The b* parameter indicates yellowing in polyurethane-based varnishes or degradation of lignin and holocellulose. The a* parameter shifted towards red for softwood samples treated with transparent varnish, likely due to the presence of phenols and flavonoids in conifers. The total colour change exhibited the most significant alterations during the first 120 hours of AW. Unprimed samples experienced considerable damage during the AW process. ATR FT-IR analysis did not reveal any significant differences in coatings resulting from various degreasing methods. This research showed that plasma degreasing is as effective as traditional methods, without significantly affecting the coating's appearance. Future research will involve weathering samples under natural conditions via outdoor exposure. Additionally, different wood species and coatings could be tested. Declarations CRediT author statement Neja Bizjak Štrus: Conceptualization, Investigation, Formal analysis, Writing – Original Draft, Visualization. Zlata Kelar Tučeková: Formal analysis, Investigation, Funding acquisition, Writing – Review & Editing. Dávid Brodňanský: Investigation, Writing – Review & Editing. Jakub Kelar: Conceptualization, Investigation, Resources, Writing – Review & Editing, Funding acquisition. Sebastian Dahle: Conceptualization, Investigation, Writing – Original Draft, Writing – Review & Editing, Supervision, Project administration, Funding acquisition. Data availability statement The raw and analysed data is available via Zenodo at https://doi.org/10.5281/zenodo.16628557 Disclosure statement No potential conflict of interest was reported by the author(s). Funding This research was supported by the project LM2023039 funded by the Ministry of Education, Youth, and Sports of the Czech Republic and by the Slovenian Research and Innovation Agency under research programme funding No. P4-0015, “Wood and lignocellulose composites” and research project No. N4-0267, “Plasma treatment of biobased porous heterogeneous substrates". ORCID Neja Bizjak Štrus http://orcid.org/0009-0006-8479-3221 Zlata Kelar Tučeková https://orcid.org/0000-0002-1369-5783 Dávid Brodňanský https://orcid.org/0009-0000-1641-509X Jakub Kelar https://orcid.org/0000-0002-4731-2875 Sebastian Dahle http://orcid.org/0000-0001-7568-0483 References Acda MN, Devera EE, Cabangon RJ, Ramos HJ (2012) Effects of plasma modification on adhesion properties of wood. Int J Adhes Adhes 32:70–75. https://doi.org/10.1016/j.ijadhadh.2011.10.003 Allen M (2006) The Complete Guide to Wood Finishes: How to Apply and Restore Lacquers, Polishes, Stains and Varnishes. 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Forests 10:903. https://doi.org/10.3390/f10100903 ISO/DIS 7724-2:1997, Paints and Varnishes — Colourimetry — Part 2: Colour measurement (Revision of ISO 7724-2:1984) Jablonský M, Šmatko L, Botkova M, Tino R, Šima J (2016) Modification of wood wettability (European beech) by diffuse coplanar surface barrier discharge plasma. Surfaces 50:41–48. Jamali A, Evans PD (2011) Etching of wood surfaces by glow discharge plasma. Wood Sci Technol 45:169–182. https://doi.org/10.1007/s00226-010-0317-7 Kim TH, Kim M, Lee W, Kim H-G, Lim C-S, Seo B (2019) Synthesis and characterization of a polyurethane phase separated to nano size in an epoxy polymer. Coatings 9:319. https://doi.org/10.3390/coatings9050319 Klarhöfer L, Viöl W, Maus-Friedrichs W (2010) Electron spectroscopy on plasma treated lignin and cellulose. Holzforschung 64:261–267. https://doi.org/10.1515/hf.2010.048 Klein A, Grabner M (2015) Analysis of construction timber in rural Austria: Wooden log walls. Int J Archit Herit 9:553–563. https://doi.org/10.1080/15583058.2013.804608 Klingner S, Voigts F, Viöl W, Maus-Friedrichs W (2013) Analysis of plasma degreased aluminium foil with XPS. Surf Eng 29:396–401. https://doi.org/10.1179/1743294413Y.0000000129 Kogelschatz U (2004) Atmospheric-pressure plasma technology. Plasma Phys Control Fusion 46:B63–B75. https://doi.org/10.1088/0741-3335/46/12B/006 Kozlowska M, Brzezinska E, Stobiecki M (2007) Sensitivity differences and accumulation of screening compounds in three conifer plants under enhanced UV-B radiation. Pol J Environ Stud 16:823–830 Krüger P, Knes R, Friedrich J (1999) Surface cleaning by plasma-enhanced desorption of contaminants (PEDC). Surf Coat Technol 112:240–244. https://doi.org/10.1016/S0257-8972(98)00777-4 Liu Z, Parida S, Prasad R, Pandey R, Sharma D, Barman I (2022) Vibrational spectroscopy for decoding cancer microbiota interactions: Current evidence and future perspective. Semin Cancer Biol 86:743–752. https://doi.org/10.1016/j.semcancer.2021.07.004 Lux C, Szalay Z, Beikircher W, Kovácik D, Pulker HK (2013) Investigation of the plasma effects on wood after activation by diffuse coplanar surface barrier discharge. Eur J Wood Wood Prod 71:539–549. https://doi.org/10.1007/s00107-013-0706-3 McFarling SM, Morris PI. (2005) High performance wood decking. In: Proc 26th Annu Meet Can Wood Preserv Assoc, Toronto, Canada, pp 99–109 McGreer M (2001) Atlas weathering testing guidebook. Atlas Material Testing Technology LLC, Chicago. Md Salim R, Asik J, Sarjadi MS (2021) Chemical functional groups of extractives, cellulose and lignin extracted from native Leucaena leucocephala bark. Wood Sci Technol 55:295–313. https://doi.org/10.1007/s00226-020-01258-2 Odrášková M, Ráhel’ J, Zahoranová A, Tino R, Cernák M (2008) Plasma activation of wood surface by diffuse coplanar surface barrier discharge. Plasma Chem Plasma Process 28:203–211. https://doi.org/10.1007/s11090-007-9117-8 Petric M (2013) Surface modification of wood. Rev Adhes Adhes 1:216–247. https://doi.org/10.7569/RAA.2013.097308 Pittaway MD (2023) Towards more sustainable materials for boat decking: Novel fillers for light-weighting and enhanced recyclability. Dissertation, Manchester Metropolitan University. https://e-space.mmu.ac.uk/633436/ Plötze M, Niemz P (2011) Porosity and pore size distribution of different wood types as determined by mercury intrusion porosimetry. Eur J Wood Wood Prod 69:649–657. https://doi.org/10.1007/s00107-010-0504-0 Pommier R, Grimaud G, Prinçaud M, Perry N, Sonnemann G (2016) Comparative environmental life cycle assessment of materials in wooden boat ecodesign. Int J Life Cycle Assess 21:265–275. https://doi.org/10.1007/s11367-015-1009-1 Primc G, Mozetic M (2019) Neutral reactive gaseous species in reactors suitable for plasma surface engineering. Surf Coat Technol 376:15–20. https://doi.org/10.1016/j.surfcoat.2018.11.103 Rehn P, Viöl W (2003) Dielectric barrier discharge treatments at atmospheric pressure for wood surface modification. Holz Roh Werkst 61:145–150. https://doi.org/10.1007/s00107-003-0369-6 Rossi S, Fedel M, Petrolli S, Deflorian F (2016) Accelerated weathering and chemical resistance of polyurethane powder coatings. J Coat Technol Res 13:427–437. https://doi.org/10.1007/s11998-015-9764-2 Rosu D, Rosu L, Cascaval CN (2009) IR-change and yellowing of polyurethane as a result of UV irradiation. Polym Degrad Stab 94:591–596. https://doi.org/10.1016/j.polymdegradstab.2009.01.013 Schauwecker C, Preston A, Morrell JJ (2009) A new look at the weathering performance of solid-wood decking materials. J Coat Technol 6:32–38. Sharma G, Wu W, Dalal EN (2005) The CIEDE2000 color-difference formula: Implementation notes, supplementary test data, and mathematical observations. Color Res Appl 30:21–30. https://doi.org/10.1002/col.20070 SIST EN ISO 2813:2014, Paints and varnishes — Determination of specular gloss of non-metallic paint films at 20°, 60° and 85° (ISO 2813:1994, including Technical Corrigendum 1:1997) Šimor M, Ráhel’ J, Vojtek P, Cernák M, Brablec A (2002) Atmospheric-pressure diffuse coplanar surface discharge for surface treatments. Appl Phys Lett 81:2716–2718. https://doi.org/10.1063/1.1513185 Talviste R, Galmiz O, Stupavská M, Ráhel’ J (2020) Effect of DCSBD plasma treatment distance on surface characteristics of wood and thermally modified wood. Wood Sci Technol 54:651–665. https://doi.org/10.1007/s00226-020-01175-4 Talviste R, Galmiz O, Stupavská M, Tuceková Z, Kaarna K, Kovácik D (2019) Effect of DCSBD plasma treatment on surface properties of thermally modified wood. Surf Interfaces 16:8–14. https://doi.org/10.1016/j.surfin.2019.04.005 Teischinger A (2017) From forest to wood production—A selection of challenges and opportunities for innovative hardwood utilization. In: Proc 6th Int Sci Conf Hardwood Processing, Lahti, Finland, pp 25–28. https://core.ac.uk/download/pdf/149827376.pdf#page=14 Tucker W (2022) Nonmetallic materials in marine service. In: Shifler DA (ed) LaQue’s Handbook of Marine Corrosion, 1st edn. Wiley, New Jersey, pp 421–439. https://doi.org/10.1002/9781119788867.ch16 Wade LG (2013) Organic chemistry, 8th edn. Pearson, Boston Wakeling R, Morris P (2014) Wood deterioration: Ground contact hazards. In: Schultz TP, Goodell B, Nicholas DD (eds) ACS Symposium Series, Vol. 1158. American Chemical Society, pp 131–146. https://doi.org/10.1021/bk-2014-1158.ch007 Žigon J, Petric M, Dahle S (2018) Dielectric barrier discharge (DBD) plasma pretreatment of lignocellulosic materials in air at atmospheric pressure for their improved wettability: A literature review. Holzforschung 72:979–991. https://doi.org/10.1515/hf-2017-0207 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 19 Apr, 2026 Read the published version in Cellulose → Version 1 posted Editorial decision: Revision requested 20 Aug, 2025 Editor assigned by journal 20 Aug, 2025 Submission checks completed at journal 31 Jul, 2025 First submitted to journal 31 Jul, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7259572","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":503324087,"identity":"a34fd894-8355-40e7-bd90-0bc0b97f71ea","order_by":0,"name":"Neja Bizjak Štrus","email":"","orcid":"","institution":"University of Ljubljana","correspondingAuthor":false,"prefix":"","firstName":"Neja","middleName":"Bizjak","lastName":"Štrus","suffix":""},{"id":503324088,"identity":"968583f7-79c5-48b7-a91c-c4a73eed32be","order_by":1,"name":"Zlata Kelar Tučeková","email":"","orcid":"","institution":"Masaryk University","correspondingAuthor":false,"prefix":"","firstName":"Zlata","middleName":"Kelar","lastName":"Tučeková","suffix":""},{"id":503324089,"identity":"2650ffc2-fb28-4398-96b6-9597bfb0780c","order_by":2,"name":"Dávid Brodňanský","email":"","orcid":"","institution":"Masaryk University","correspondingAuthor":false,"prefix":"","firstName":"Dávid","middleName":"","lastName":"Brodňanský","suffix":""},{"id":503324090,"identity":"84c4bb66-95da-430f-900d-0a4805ae4278","order_by":3,"name":"Jakub Kelar","email":"","orcid":"","institution":"Masaryk University","correspondingAuthor":false,"prefix":"","firstName":"Jakub","middleName":"","lastName":"Kelar","suffix":""},{"id":503324091,"identity":"071f2d71-e605-44a1-8d53-81a93b9a15ca","order_by":4,"name":"Sebastian Dahle","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABKElEQVRIie2RMUvDQBTHXzi4LvcBDiK9r/BCoBVS9atcCaSLlYAgThIINJN7N79CxEGypQR0qc5KBxVXh4pLioLeBYwOp+Imcr/heMP78f5/DsBi+ZMw/XD9IIEYukhKPcOakwCUXyryXUHwkcpGYT8o0CrDnMqP6yZEdjh7XNXrog/k+CnGweiUAnXjGBhJOnemKzi/DF0muVckdNedYjQuJkqZNsEYGhW+ja7q4uQlQ5dhNc5vEqqGV60Yu4ijB39VS76lFP9ZbY7wDLSir3RujfWvWI+rYEOl9NRmKT8pYA4234kCFvEwr+hewDD0iomTBo2SmruI7KK6rgcHG/l5erJg+5uiT8lswV6g62XZ/dIUrIW0k/5DhZd+u29C/NqwWCyWf8ob4q9Xn8cliXIAAAAASUVORK5CYII=","orcid":"","institution":"University of Ljubljana","correspondingAuthor":true,"prefix":"","firstName":"Sebastian","middleName":"","lastName":"Dahle","suffix":""}],"badges":[],"createdAt":"2025-07-31 08:08:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7259572/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7259572/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10570-026-07041-z","type":"published","date":"2026-04-19T15:57:41+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":90418977,"identity":"de4c7ead-662e-4eb7-8ce5-82fc6b39ac7d","added_by":"auto","created_at":"2025-09-02 13:39:50","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":176098,"visible":true,"origin":"","legend":"\u003cp\u003eAverage gloss at four measurement points during AW of the samples (with standard error), as well as a dark reference for each method (bars represent dark reference, and lines represent AW samples). T/P/AMAL1030 – degreased with turpentine/plasma or petroleum-based solvent. P+HR – primer with hard racing, HR – no primer, just hard racing and AMAL – alkyd-based clear varnish. t0 – before AW, t72 – after 72h of AW, t120 – after 120h of AW, t240 – after AW.\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-7259572/v1/8973663da433b9a20d92069c.png"},{"id":90418976,"identity":"d94309e1-2e2c-4010-9427-04d5837af880","added_by":"auto","created_at":"2025-09-02 13:39:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":73387,"visible":true,"origin":"","legend":"\u003cp\u003eChange in colour (ΔE) compared to colour before artificial weathering (t0). t72 – after 72 h of AW, t120 – after 120 h of AW, t240 – after AW. T/P/AMAL1030 – degreased with turpentine/plasma or petroleum-based solvent. P+HR – primer with hard racing, HR – no primer, just hard racing and AMAL – alkyd-based clear varnish.\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-7259572/v1/1756bd342cb1d890e2aa5c28.png"},{"id":90418979,"identity":"f19ae63a-8e0a-4a1b-b890-7ccd4a938922","added_by":"auto","created_at":"2025-09-02 13:39:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":490133,"visible":true,"origin":"","legend":"\u003cp\u003eSome examples of artificially weathered samples. a) cracks and coating peeling of unprimed samples, b) yellowing of the antifouling paint, c) washing of the alkyd-based clear varnish with greyish patches. Dark reference samples: d) primed sample with antifouling paint, e) unprimed sample with antifouling paint, f – h samples with alkyd-based clear varnish: f) spruce wood, g) pine wood, h) beech wood.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-7259572/v1/8fbcf89ee09fdad45397abca.png"},{"id":90419387,"identity":"1a43c363-9679-422a-8236-de46b1d90f9d","added_by":"auto","created_at":"2025-09-02 13:47:50","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":295390,"visible":true,"origin":"","legend":"\u003cp\u003eThe spectra labelled a-c represent the woods of spruce, pine, and beech, respectively. In each spectrum, the first one shows the wood before any degreasing treatments. This is followed by the spectra of the same wood types after being degreased with AMAL1030, turpentine, and plasma. The spectra labelled d-f illustrate the coatings applied to different wood species as well as on glass, which serves as a reference. In all of these spectra, the top one showcases the varnish coating on the glass, followed by the coatings on pine, spruce, and beech wood.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-7259572/v1/94decbac9efa05784d5b1af8.png"},{"id":107351843,"identity":"c3d16cf2-ca28-4f8d-951e-b218ec0164e0","added_by":"auto","created_at":"2026-04-20 16:12:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1460704,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7259572/v1/9fdbf5d7-0459-4fe4-bba5-d22c4ad10214.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"DCSBD Plasma Treatment as an Alternative to Commercial Surface Degreasing Agents Before Applying Wood Coatings","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe use of wood in a variety of sectors and applications is steadily growing, with softwoods being predominant, e.g. in the construction industries (Klein and Grabner \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) and hardwoods being predominant, e.g. in the furniture sector (Teischinger \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). While some wood species exhibit a natural resistance to decay in outdoor conditions, most wood materials have to be protected from weathering, including through constructive measures, impregnation and coating. Most challenging environments are those of constant water contact, such as wood in ground contact (Wakeling and Morris \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) or in marine environments (Arango et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Corresponding demands are particularly elevated in high-value added products, as is the case, e.g. for the wooden decking on boats and yachts, as the weathering conditions are specifically harsh and expectations for aesthetics and longevity are particularly high. Traditionally, tropical hardwoods would have been used for the decking due to their decay resistance, whereas durable hardwoods like oak were less preferred. However typical softwoods were valued for their good mechanical properties at low weight, more specifically, spruce was commonly used for spars, whereas pine was recommended for planking due to its high pitch content (Hillman \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e1956\u003c/span\u003e). More recently, however, tropical hardwoods and other exotic woods have become unfavourable due to their environmental impact and deforestation. Instead, polymers and composites have strongly gained in importance over teak and other tropical hardwoods (Pittaway \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Tucker \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Even more recommendable, are locally grown wood varieties to ensure sustainability, high environmental standards and ecodesign (Pommier et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). However, to make such wood species viable, coatings with superb performance are essential. In a recent study, Scots pine was found as the most durable local wood species for decking application with a 45- and 150-times longer estimated service life than the most abundant local wood species, beech and Norway spruce, respectively (Brischke et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe surface protection by a suitable coating system is essential for such locally grown wood varieties to be utilised in such demanding applications as decking (Humar et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Typical coating systems in such applications may employ epoxy or acrylic polymer systems as basis for the formulation (Bulian and Graystone \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). A crucial step in ensuring high durability and performance of the coatings, wooden surfaces need to be properly prepared in the ways indicated by the manufacturers for commercial coating systems, as deviations regularly lead to early delamination and failure (Brooke et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). Several manufacturers of coatings intended for boat decking prescribe the need for \u0026ldquo;degreasing\u0026rdquo;, i.e. scrubbing the surface with alcohol or nitro solvents \u0026ndash; usually this is prescribed for wood species with high resin contents (Allen \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), whereas some manufacturers recommend degreasing for all surfaces regardless of the wood species. For high-performance wooden decking, impregnation is another treatment step adding to a significantly increased service life. Here, typical agents deposited into the bulk of the wooden parts are chromated copper arsenate or copper azole (McFarling and Morris \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Schauwecker et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e\u003cp\u003ePlasma discharges are an environmentally friendly technology used in many sectors for degreasing, thereby effectively replacing solvent-based processing steps (Klingner et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Kr\u0026uuml;ger et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e1999\u003c/span\u003e; Primc and Mozetič \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Non-thermal plasmas (NTP) have been utilised on wood surfaces for a variety of purposes, including for increasing adhesion and performance of coating systems and adhesive joints (Acda et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Dahle et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Petrič \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Most commonly, air is used as the process gas for NTP treatments at atmospheric pressure, as the most accessible and cost-effective variety of plasma treatments for wooden work pieces (Žigon et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The effects of NTP treatments on wood have been demonstrated to modify the wood surfaces chemically (Lux et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Rehn and Vi\u0026ouml;l \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2003\u003c/span\u003e), including the generation of polar groups on lignin and the modification of cellulose (Klarh\u0026ouml;fer et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) and the removal of extractives and volatile organic compounds from the surface-near parts of the wood (Avramidis et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2012\u003c/span\u003e), as well as being able to modify the wood surface morphologically through etching upon prolonged treatments (Jamali and Evans \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eDielectric barrier discharge (DBD) plasmas represent a well-scalable NTP technology that operates at low temperatures, thereby minimising energy losses (Kogelschatz \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). In contrast to plasma jets, such discharges can be applied on larger areas and exclude the need for scanning that narrow jets typically impose (Žigon et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). In particular, the most easily scalable variety of DBD plasmas is the diffuse coplanar surface barrier discharge (DCSBD) (Odr\u0026aacute;škov\u0026aacute; et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2008\u003c/span\u003e), which provides the additional benefit of being largely independent of the material and thickness of the work piece to be treated, but requires a certain flatness to be applicable on a work piece (Talviste et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). On wood substrates, DCSBD has been demonstrated to chemically activate surfaces of different wood species, thereby improving its wettability (Jablonsk\u0026yacute; et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). With that, DCSBD appears most applicable and promising for applications, especially intended for cladding and decking applications.\u003c/p\u003e\u003cp\u003eIn this study, we investigated the use of DCSBD plasma treatments replacing conventionally prescribed solvent-based degreasing prior to deposition of coatings for boat decking. Substrates included European red pine as a common, locally grown boat decking material, as well as Norway spruce and European beech as the most abundant locally grown wood species. Two different commercial coating systems were used, thereby covering epoxy- and acrylic-based formulations. The performance of the sample systems was investigated using artificially accelerated weathering (AW), combined with the analysis of gloss, colour and chemical changes. For the experiment, we also conducted a preliminary life cycle analysis and cost analysis (Bizjak Štrus et al. 2025).\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003ch2\u003e2.1.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Wood degreasing\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eBoards made of European beech (\u003cem\u003eFagus sylvatica\u0026nbsp;\u003c/em\u003eL.), European red pine (\u003cem\u003ePinus sylvestris\u0026nbsp;\u003c/em\u003eL.), and Norway spruce (\u003cem\u003ePicea abies\u0026nbsp;\u003c/em\u003e(L.) Karst.) with dimensions 70\u0026times;30\u0026times;5\u0026nbsp;mm\u003csup\u003e3\u003c/sup\u003e and radial orientation of the fibres were used for the experiment. The surface was planed flat without any additional sanding. Samples were conditioned to natural conditions of 20 \u0026deg;C and 65 % relative humidity, corresponding to a wood moisture content of 10-12 %. Samples were degreased with DCSBD plasma, turpentine (Terpentinovo olje, Chemcolor Sevnica d.o.o., Blanca, Slovenia) or a commercial petroleum-based solvent (AMAL 1030 razrdečilo, AMAL d.o.o., Ljubljana, Slovenia) (AMAL1030), respectively. Turpentine and AMAL1030 were applied with a paper towel. A DCSBD plasma (CEPLANT, Brno, Czech Republic) degreasing process was optimised based on water contact angle measurements (see below) to improve efficiency, including adjusting the plasma treatment duration and the electrode\u0026apos;s distance from the board\u0026apos;s surface. As a result of the optimisation process, specimens were treated for 10 s with an input power of 400 W at a distance of 0.5 mm from the DCSBD plasma unit, thereby accommodating for minute deformations (cupping, warping) of the specimens, while also taking into account previously published data (Talviste et al. 2019).\u003c/p\u003e\n\u003ch2\u003e2.2.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Wood degreasing\u0026nbsp;\u003c/h2\u003e\n\u003ch3\u003e2.2.1.\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Diffuse coplanar surface barrier discharge (DCSBD) plasma device\u003c/h3\u003e\n\u003cp\u003eThe system of DCSBD plasma consists of parallel silver electrodes embedded in 96 % aluminium using a multilayering lamination technique, as was described in detail before (Čern\u0026aacute;k et al. 2009). This device operates at high-frequency high-voltage of approx. 15\u0026nbsp;kHz with peak-to-peak voltages of 10\u0026nbsp;\u0026ndash;\u0026nbsp;20\u0026nbsp;kV. Such configuration provides macroscopically homogeneous plasma in ambient air at atmospheric pressure. The generated plasma layer has an estimated effective thickness of approx. 0.3\u0026nbsp;mm, depending on the generating conditions, such as gas composition or input power (\u0026Scaron;imor et al. 2002). In our experiments, we used the distance between the wood surface and the ceramic surface of 0.5\u0026nbsp;mm due to the possible unevenness of the wood. The effect of plasma in this distance was tested prior to the rest of the experiments and was deemed satisfactory. The mass loss determined by weighing before and after degreasing amounted to 0.2\u0026nbsp;% or less of the specimens\u0026rsquo; masses and was thus found to be insignificant.\u003c/p\u003e\n\u003ch2\u003e2.3. Water contact angle measurements (WCA)\u003c/h2\u003e\n\u003cp\u003eThe water contact angles were measured with deionised water after degreasing for all three above-mentioned methods using the optical goniometer. WCA was evaluated by Young\u0026ndash;Laplace analysis using the software. In total, 7 \u0026ndash; 13 droplets for different parameters were analysed, and each droplet was measured for 63 s (1.9 images per second). The measurement of the WCA started approximately 2 s after the first contact of the drop with the sample surface. The measurements began right after the degreasing method was applied to prevent the measured values from being affected by ageing.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003e2.4.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Wood coating\u003c/h2\u003e\n\u003cp\u003eAfter degreasing, the samples were coated. Samples that were cleaned with AMAL1030 and one-third of plasma-cleaned samples were coated with an alkyd-based clear varnish (Lak za čolne, AMAL d.o.o., Ljubljana, Slovenia) (AMAL) and applied in two layers. Half of the turpentine-cleaned boards and one-third of the plasma-treated wood were primed with epoxy-based primer (Curing agent 95360 and light primer 45559, HEMPEL d.o.o., Umag, Croatia) and then coated with two layers of antifouling paint (Hard Racing white 76300, HEMPEL d.o.o., Umag, Croatia) (HR), while the remaining cleaned samples were just coated with two layers of HR (without primer). The varnishes and primer were applied as per the manufacturer\u0026apos;s instructions.\u003c/p\u003e\n\u003ch2\u003e2.5.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Artificial weathering (AW)\u003c/h2\u003e\n\u003cp\u003eThe artificial ageing chamber, according to the standard EN ISO 11341:2004 in the interior mode, was used for AW. Degreased and varnished samples underwent 240 hours of AW. They were loaded on the tray with a spacing of around 1 cm between them. \u0026nbsp;The xenon-arc lamp was used in the AW chamber with a 3-mm window glass filter to produce spectra equivalent to sunlight coming through the window glass (McGreer 2001). The lamp\u0026rsquo;s parameters and the conditions in the chamber during the AW test were as follows: irradiance control was set to 340 nm, the cycle to 102/18, the irradiance power to 0.35 W/m\u003csup\u003e2\u003c/sup\u003e, the chamber air temperature to 38 \u0026deg;C, the black standard temperature to 68 \u0026deg;C, and the relative air humidity to 68 %. Water was introduced in the form of spray, and filter daylight was selected. The cycle was interrupted twice for gloss and colour measurements. After AW, the samples were removed from the chamber for further work and analysis.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003e2.6.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Gloss and colour measurements\u003c/h2\u003e\n\u003cp\u003eGloss and colour were measured before AW, after 72 and 120 hours and at the end of AW. Gloss was measured following the SIST EN ISO 2813:1999 standard using a gloss meter. Measurements were taken on each sample at three locations: one in the middle and two near opposite edges. The measurements were taken at a 60\u0026deg; angle of the incident light, parallel to the board fibres in the longitudinal direction. Areas with natural discolouration or cramps were avoided.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe colour was measured following the standard ISO/DIS 7724-2:1997 using a spectrophotometer with a standard D65 light source. The CIELAB parameters (\u003cem\u003eL*\u003c/em\u003e, \u003cem\u003ea*\u003c/em\u003e, and \u003cem\u003eb*\u003c/em\u003e), their changes (\u0026Delta;\u003cem\u003eL*\u003c/em\u003e, \u0026Delta;\u003cem\u003ea*,\u003c/em\u003e and \u0026Delta;\u003cem\u003eb*\u003c/em\u003e), and the total colour change (\u0026Delta;\u003cem\u003eE*\u003c/em\u003e) were determined with the CIEDE2000 formula (Sharma et al. 2005), using Eq. (1).\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 87.438%;\"\u003e\n \u003cp\u003e\u003cimg width=\"222\" height=\"22\" src=\"data:image/png;base64,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\" alt=\"image\"\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.562%;\"\u003e\n \u003cp\u003eEq. (1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe \u003cem\u003eL*\u003c/em\u003e parameter ranges from 0 to 100, where 0 represents total darkness, and 100 represents maximum lightness. It is calculated based on the relative luminance of a sample colour, derived from the tristimulus values that represent the colour\u0026apos;s response to light under a standard light source. Parameter \u003cem\u003eL*\u003c/em\u003e is represented on the polar axis in the three-dimensional colour space (Durmus 2020).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe \u003cem\u003ea*\u003c/em\u003e parameter ranges between -300 and 220, where positive values indicate redness and negative greenness. Parameter \u003cem\u003eb\u003c/em\u003e* ranges between -200 and 160; positive values indicate yellowness, and negative \u003cem\u003eb*\u003c/em\u003e values indicate blueness. Both parameters are calculated based on the relative luminance of a sample colour, derived from the tristimulus values that represent the colour\u0026apos;s response to light under a standard light source (Durmus 2020). In addition to these separate parameters, a total colour change can be calculated using Eq. (1), which considers all measured parameters.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMeasurement areas were in the middle and on the opposite edges of the sample, totalling three measurements per board. Natural discolouration areas or cramps were avoided. For reference, one specimen per sample system (substrate material\u0026nbsp;\u0026times;\u0026nbsp;degreasing technique\u0026nbsp;\u0026times;\u0026nbsp;coating type) was stored in the dark.\u003c/p\u003e\n\u003ch2\u003e2.7.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy\u003c/h2\u003e\n\u003cp\u003eATR FT-IR spectroscopic measurements of the control and aged wood surfaces were performed using an ATR FT-IR spectrometer with a LiTaO\u003csub\u003e3\u003c/sub\u003e detector type in the absorbance mode. The spectra were corrected for background, and 16 scans per sample were collected at a wavelength from 400 to 4000 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e at a resolution of 0.5 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e. Spectra were interpreted later using the software. Measurements were taken after each layer of varnish, along with measurements of the coating on glass to serve as a background. \u0026nbsp;\u003c/p\u003e"},{"header":"3. Results with Discussion","content":"\u003ch2\u003e3.1.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Water contact angle\u003c/h2\u003e\n\u003cp\u003eAfter testing different plasma settings, the optimal parameter with a low WCA and treatment time was selected. Contact angles are represented in Table 1. Almost all methods of degreasing reduced the WCA, with the most significant decrease observed in the beech and pine wood treated with plasma. There were statistically significant differences in WCA between all methods, except for pine boards that were untreated and treated with AMAL1030, as well as between AMAL1030-treated and plasma-treated spruce boards. When comparing turpentine and AMAL1030, turpentine showed a higher decrease of WCA in all wood species.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e1\u003c/strong\u003e Mean and standard error of water contact angle (WCA) after different degreasing methods. Highlighted values represent the statistical insignificance of WCA between treatments within the wood type.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"609\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTreatment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003ePine [\u0026deg;]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eBeech [\u0026deg;]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\"\u003e\n \u003cp\u003eSpruce [\u0026deg;]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003emean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003emean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003emean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSE\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eUntreated\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e80.4\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e69.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e51.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eDCSBD plasma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e34.9\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTurpentine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e49.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e31.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAMAL1030\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e79.4\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e52.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e42.8\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.16\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003e3.2.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Gloss\u003c/h2\u003e\n\u003cp\u003eIn all three tested wood species, the highest gloss was observed in wood varnished with AMAL, and the most changes in gloss were noticed after 72 hours of AW. The HR fully coated the wood, so the wood colour was not visible and could not affect the varnish gloss. The gloss of the HR depended solely on the varnish itself, whereas the gloss of AMAL could be affected by the underlying wood colour. At the beginning of the experiment, beech wood with AMAL varnish had the highest gloss level. This is likely due to the higher density of beechwood, which contributes to a smoother surface finish. The density was calculated based on the samples\u0026apos; volume and mass, showing that beech wood (665\u0026nbsp;kg/m\u003csup\u003e3\u003c/sup\u003e) is denser than spruce (435\u0026nbsp;kg/m\u003csup\u003e3\u003c/sup\u003e) or pine wood (634\u0026nbsp;kg/m\u003csup\u003e3\u003c/sup\u003e). This higher density may enhance light reflectivity and contribute to a glossier finish. Moreover, the hardwood has more porosity and varnish can penetrate into the wood, fill the micropores, and result in a smoother surface with higher gloss (Pl\u0026ouml;tze and Niemz 2011). However, after exposure to AW, the AMAL beech wood experienced a greater loss of gloss after 72 h of AW than the other two wood types (\u0026Delta;t\u003csub\u003e1\u003c/sub\u003e = gloss before AW \u0026ndash; gloss after 72 hours of AW). When comparing different types of wood, it was observed that beechwood coated with AMAL exhibited the highest level of gloss change after the first three days of AW types compared to spruce and pine wood (beech \u0026Delta;t\u003csub\u003e1\u003c/sub\u003e = 41.3 GU, spruce \u0026Delta;t\u003csub\u003e1\u003c/sub\u003e = 14.3 GU, pine \u0026Delta;t\u003csub\u003e1\u003c/sub\u003e = 21.7 GU). The final comparison is between degreasing with turpentine and plasma, as well as AMAL1030 and plasma. The t-test revealed no statistically significant difference before AW between plasma and turpentine-treated wood with HR and no difference between plasma and AMAL1030 for AMAL varnish. A statistically significant difference after AW was found between plasma and AMAL1030 degreasing and coated with AMAL for all three wood species. Plasma-treated spruce wood lost more gloss compared to AMAL1030, whereas plasma-degreased pinewood and beechwood lost less gloss compared to AMAL1030. The gloss of coated samples during AW is shown in\u0026nbsp;Fig.3\u0026nbsp;together with values of dark reference for each treatment.\u003c/p\u003e\n\u003ch2\u003e3.3.\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Colour\u003c/h2\u003e\n\u003ch3\u003e3.3.1.\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Parameter \u003cem\u003eL*\u003c/em\u003e\u003c/h3\u003e\n\u003cp\u003eWhen comparing colour, AMAL and HR cannot be compared because the wood\u0026apos;s colour influences the AMAL\u0026apos;s colour. In contrast, the HR is white, but primed samples can appear greyer. Both provide good coverage. AW lowered the L* parameter for all wood species, causing the varnish to darken after exposure to UV radiation and moisture. This was confirmed with a one-way ANOVA test with an additional Student\u0026rsquo;s Post Hoc test for values within treatment. After AW, lightness of pine and spruce wood degreased with plasma did not differ from turpentine or AMAL1030 degreased samples. In beechwood, samples degreased with plasma or turpentine and then coated with primer and HR showed no difference in the L* parameter after AW. However, unprimed HR samples and AMAL coated samples indicated a statistically significant difference in lightness between plasma and turpentine or AMAL1030 degreased samples. In both scenarios, plasma-degreased samples exhibited a lower L* parameter. Some measurements showed a statistically significant difference of L* before AW, but there was no difference at the end of AW. Some intermediate measurements indicated statistically significant differences but did not consistently translate into final significant differences between treatments.\u003c/p\u003e\n\u003cp\u003eParameters a* and b*\u003c/p\u003e\n\u003cp\u003eInside all treatments with AMAL, one-way ANOVA with Students\u0026rsquo; Post Hoc test confirmed wood colour shifted towards yellow (change in b* parameter), which can be addressed to the yellowing of polyurethane-based varnishes (Rossi et al. 2016; Rosu et al. 2009), as well as lignin and holocellulose degradation (Geffertov\u0026aacute; et al. 2018). This is especially true for spruce and pinewood. In HR coated samples (primed and unprimed), there is less change in b* parameter. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn HR-coated wood, there is not much difference in the a* parameter after AW, but there is a significant difference in AMAL-coated wood. When pine and spruce are treated with AMAL, the a* parameter value indicates that the wood becomes redder. However, this does not hold true for beechwood. Initially, it may show this trend, but then it changes, and ultimately, the wood shows more greenness. Redness might be due to the accumulation of phenols and flavonoids present in conifers (Kozłowska et al. 2007).\u003c/p\u003e\n\u003ch3\u003e3.3.2.\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Colour change \u0026Delta;E\u003c/h3\u003e\n\u003cp\u003eThe colour change was evaluated as a mean colour change compared to the colour before AW. A graphical representation of colour change can be seen in Fig.2. The greatest change can be observed in wood coated with AMAL varnish. The most significant changes occured after 120 hours of AW. The colour change is important information because it reflects the colour change, not just individual parameters (Geffertov\u0026aacute; et al. 2018). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBefore the AW, the colour on all boards was intact. The observation of the samples revealed a colour change. After 72 hours of AW, noticeable changes occurred, particularly in the samples that did not have primer before applying the HR. The absence of primer resulted in cracking and peeling of the colour from all tested wood species, with beechwood being the most affected. Some noticeable cracks were also present in the primed samples, appearing at the edges of the boards. All boards appeared darker, especially AMAL coated samples. After 120 hours of AW, samples without primer showed more cracks, and the coating started to peel off, particularly from the beechwood. The cracks in the primed samples did not progress as much as those in the unprimed samples. The colour became darker for all samples with HR coating, and the edges turned yellow. Samples with an AMAL varnish became darker, and some of them acquired a dark grey colour on the edge. During the AW, samples without primer were significantly damaged, with more than half of the coating peeling off in some cases. Samples with primer showed increased cracking at the edges, and the coating developed yellow patches of discolouration. AMAL varnished pine and spruce samples appeared redder. AMAL varnish on beechwood samples was washed away, which affected the wood underneath, resulting in greyish patches. Additionally, the edges appeared greyish. A few examples of AW samples and dark reference samples can be observed in Fig.3.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe remaining coating from unprimed samples coated with HR was measured, and the data is represented in Table 2. The statistical analysis did not show a difference in peeled coating between plasma and turpentine-degreased samples. Between 13% and 56% of the coating peeled from beech samples after ten days of AW regardless of degreasing technique.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e Average area of remaining coating after ten days of artificial ageing of beech wood (B), spruce wood (S), pine wood (P), coated with antifouling paint without primer. T-test (TT) was performed to compare turpentine (T) and plasma (P) degreased samples.\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"274\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003esample\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003earea [cm\u003csup\u003e2\u003c/sup\u003e]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e\u003cstrong\u003earea [%]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eP\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;(TT)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eB_T\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e16.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e77.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026gt; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eB_P\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e9.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e44.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eS_T\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e18.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e87.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026gt; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eS_P\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e18.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e85.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP_T\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e17.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e84.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026gt; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP_P\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e16.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 70px;\"\u003e\n \u003cp\u003e77.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003ch2\u003e3.4. \u0026nbsp; \u0026nbsp; \u0026nbsp;ATR FT-IR spectra\u003c/h2\u003e\n\u003cp\u003eSpectra are divided into two regions: fingerprint and non-fingerprint region. The fingerprint region is set to be between 600 and 1400\u0026nbsp;cm\u003csup\u003e-1\u003c/sup\u003e, where most of the complex vibrations are found. The non-fingerprint region is between 1600 and 3500\u0026nbsp;cm\u003csup\u003e-1\u003c/sup\u003e and contains simple stretching vibrations. These peaks are the most characteristic and reliable (Wade 2013).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAt first, untreated and degreased samples, as well as both varnishes and primer, were analysed. Fig.4\u0026nbsp;a-c shows spectra of untreated and degreased samples. The degreased samples were expected to show some changes indicating the previous presence of fatty acids. Fatty acids contain a carboxyl functional group, so we would anticipate O-H, C=O and C-H stretches (Kim et al. 2019). Lower absorption of spruce and pine at around 2900 cm\u003csup\u003e-1\u003c/sup\u003e can be observed, which correlates with C-H stretching at CH\u003csub\u003ex\u003c/sub\u003e structures (Odr\u0026aacute;\u0026scaron;kov\u0026aacute; et al. 2008). This could be associated with the degradation of lignin, cellulose, extractives or fatty acids. Also, carboxyl groups and alkane bonds are naturally present in wood (Md Salim et al. 2021), so wood\u0026rsquo;s functional groups could mask the lack of fatty acid. Additionally, in\u0026nbsp;Fig.4\u0026nbsp;a, a change in absorption at the peak of 2360 cm-1 can be observed for AMAL1030 and turpentine degreasing method. This spectrum indicates carbon dioxide originating from the atmosphere.\u003c/p\u003e\n\u003cp\u003eAfterwards, coated samples were analysed. Fig.4 d-f shows the spectrums after applying the first layer of AMAL, primer or the first layer HR. Some peaks are slightly deformed and have different intensities. However, it can still be determined that there is no difference between wood types or plasma and degreasing treatments, regardless of treatment. AMAL, HR and primer coated on glass were also analysed, serving as a reference, and can be observed in the top spectrum of Fig.4 \u0026nbsp;d-f. The thickness of a single coating layer is approximately 90 \u0026micro;m (manufacturer\u0026apos;s information on the technical sheet), while the ATR FT-IR\u0026apos;s penetration depth is 0.5 \u0026ndash; 2 \u0026micro;m (Liu et al. 2022).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAnalysing primer and HR were trickier because there were more listed ingredients and more peaks in spectra. Primer is a mixture of epoxy base and curing agents, each with different ingredients. The first primer peaks are at 3550 and 3320\u0026nbsp;cm\u003csup\u003e-1\u003c/sup\u003e and belong to O-H and N-H stretching. Next is the dual peak at 2925 and 2850 cm\u003csup\u003e-1\u003c/sup\u003e, which belongs to C-H stretching. Alkenes from petroleum can be observed at 1650\u0026nbsp;cm\u003csup\u003e-1\u003c/sup\u003e as C=C stretch and 1600 cm\u003csup\u003e-1\u003c/sup\u003e as conjugated alkene. Peak 1243 cm\u003csup\u003e-1\u003c/sup\u003e can be from an alkyl aryl ether bridge in epoxy resin as the main ingredient of the primer base. Primer peaks can be observed in Fig.4 e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe HR spectrum (Fig.4\u0026nbsp;f) first shows a broad peak at 3390 cm\u003csup\u003e-1\u003c/sup\u003e, representing an O-H stretch from 2,5-di-tert-butylhydroquinone. It is followed by a dual peak at 2925 and 2870\u0026nbsp;cm\u003csup\u003e-1\u003c/sup\u003e, which belongs to C-H stretching, mainly from petroleum. The peak at 2160\u0026nbsp;cm\u003csup\u003e-1\u003c/sup\u003e is not as common and belongs to the stretching of S-C\u0026equiv;N from copper thiocyanate. 1730 cm\u003csup\u003e-1\u003c/sup\u003e is a ketone stretch of C=O from 4-methyl pentane-2-one. A peak at 1585 cm\u003csup\u003e-1\u003c/sup\u003e probably belongs to the carbon double bond stretch from xylene and 2,5-di-tert-butylhydroquinone. Double peaks at 1464 and 1410 cm\u003csup\u003e-1\u003c/sup\u003e are typically associated with the bending vibrations of C-H bonds in methylene (-CH\u003csub\u003e2\u003c/sub\u003e-) petroleum groups.\u003c/p\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn this experiment, we compared the DCSBD plasma degreasing method with turpentine and petroleum-based solvents on hardwood (beech) and two softwood species (pine and spruce). Additionally, we investigated how this degreasing method affects varnish application. We tested two types of varnishes, the first was AMAL, a polyurethane varnish based on modified alkyd resin, and the second was HR antifouling paint, which was applied both with and without an epoxy primer. All samples experienced gloss loss during AW. AW also reduced the value of the \u003cem\u003eL*\u003c/em\u003e parameter for all samples due to varnish darkening after exposure to UV radiation and moisture. The \u003cem\u003eb*\u003c/em\u003e parameter indicates yellowing in polyurethane-based varnishes or degradation of lignin and holocellulose. The \u003cem\u003ea*\u003c/em\u003e parameter shifted towards red for softwood samples treated with transparent varnish, likely due to the presence of phenols and flavonoids in conifers. The total colour change exhibited the most significant alterations during the first 120 hours of AW. Unprimed samples experienced considerable damage during the AW process. ATR FT-IR analysis did not reveal any significant differences in coatings resulting from various degreasing methods. This research showed that plasma degreasing is as effective as traditional methods, without significantly affecting the coating's appearance. Future research will involve weathering samples under natural conditions via outdoor exposure. Additionally, different wood species and coatings could be tested.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCRediT author statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNeja Bizjak \u0026Scaron;trus: Conceptualization, Investigation, Formal analysis, Writing \u0026ndash; Original Draft, Visualization.\u003c/p\u003e\n\u003cp\u003eZlata Kelar Tučekov\u0026aacute;: Formal analysis, Investigation, Funding acquisition, Writing \u0026ndash; Review \u0026amp; Editing.\u003c/p\u003e\n\u003cp\u003eD\u0026aacute;vid Brodňansk\u0026yacute;: Investigation, Writing \u0026ndash; Review \u0026amp; Editing.\u003c/p\u003e\n\u003cp\u003eJakub Kelar: Conceptualization, Investigation, Resources, Writing \u0026ndash; Review \u0026amp; Editing, Funding acquisition.\u003c/p\u003e\n\u003cp\u003eSebastian Dahle: Conceptualization, Investigation, Writing \u0026ndash; Original Draft, Writing \u0026ndash; Review \u0026amp; Editing, Supervision, Project administration, Funding acquisition.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe raw and analysed data is available via Zenodo at https://doi.org/10.5281/zenodo.16628557\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosure statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo potential conflict of interest was reported by the author(s).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was supported by the project LM2023039 funded by the Ministry of Education, Youth, and Sports of the Czech\u0026nbsp;Republic and by the Slovenian Research and Innovation Agency under research programme funding No. P4-0015, \u0026ldquo;Wood and lignocellulose composites\u0026rdquo; and research project No. N4-0267, \u0026ldquo;Plasma treatment of biobased porous heterogeneous substrates\u0026quot;.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eORCID\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNeja Bizjak \u0026Scaron;trus http://orcid.org/0009-0006-8479-3221\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eZlata Kelar Tučekov\u0026aacute; https://orcid.org/0000-0002-1369-5783\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eD\u0026aacute;vid Brodňansk\u0026yacute;\u003csup\u003e\u0026nbsp;\u003c/sup\u003ehttps://orcid.org/0009-0000-1641-509X\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eJakub Kelar https://orcid.org/0000-0002-4731-2875\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSebastian Dahle http://orcid.org/0000-0001-7568-0483\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAcda MN, Devera EE, Cabangon RJ, Ramos HJ (2012) Effects of plasma modification on adhesion properties of wood. 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Polym Degrad Stab 97:469\u0026ndash;471. https://doi.org/10.1016/j.polymdegradstab.2011.12.030 \u003c/li\u003e\n\u003cli\u003eBizjak-\u0026Scaron;trus N, Remic K, Kitek Kuzman M, Oblak L, Dahle S (2025) Laboratory-scale life cycle assessment and cost analysis of degreased beechwood boards. Wood Mater Sci Eng 1\u0026ndash;10. https://doi.org/10.1080/17480272.2025.2510561 \u003c/li\u003e\n\u003cli\u003eBrischke C, Meyer-Veltrup L, Bornemann T (2017) Moisture performance and durability of wooden fa\u0026ccedil;ades and decking during six years of outdoor exposure. J Build Eng 13:207\u0026ndash;215. https://doi.org/10.1016/j.jobe.2017.08.004 \u003c/li\u003e\n\u003cli\u003eBrooke P, Bennett-Kennett R, Gupta C, Santos S, Guyer E (2025) Failure of coatings on wood substrates due to surface preparation and application. J Fail Anal Prev 25:41\u0026ndash;46. https://doi.org/10.1007/s11668-024-02090-7 \u003c/li\u003e\n\u003cli\u003eBulian F, Graystone J (2009) Wood Coatings: Theory and Practice. Elsevier, Amsterdam\u003c/li\u003e\n\u003cli\u003eCern\u0026aacute;k M, Cern\u0026aacute;kov\u0026aacute; L, Hudec I, Kov\u0026aacute;cik D, Zahoranov\u0026aacute; A (2009) Diffuse coplanar surface barrier discharge and its applications for in-line processing of low-added-value materials. Eur Phys J Appl Phys 47:22806. https://doi.org/10.1051/epjap/2009131 \u003c/li\u003e\n\u003cli\u003eDahle S, Pilko M, Žigon J, Zaplotnik R, Petric M, Pavlic M (2021) An open-source surface barrier discharge plasma pretreatment for reduced cracking of outdoor wood coatings. Cellulose 28:8055\u0026ndash;8076. https://doi.org/10.1007/s10570-021-04014-2 \u003c/li\u003e\n\u003cli\u003eDurmus D (2020) CIELAB color space boundaries under theoretical spectra and 99 test color samples. 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Forests 10:903. https://doi.org/10.3390/f10100903 \u003c/li\u003e\n\u003cli\u003eISO/DIS 7724-2:1997, Paints and Varnishes \u0026mdash; Colourimetry \u0026mdash; Part 2: Colour measurement (Revision of ISO 7724-2:1984)\u003c/li\u003e\n\u003cli\u003eJablonsk\u0026yacute; M, \u0026Scaron;matko L, Botkova M, Tino R, \u0026Scaron;ima J (2016) Modification of wood wettability (European beech) by diffuse coplanar surface barrier discharge plasma. Surfaces 50:41\u0026ndash;48.\u003c/li\u003e\n\u003cli\u003eJamali A, Evans PD (2011) Etching of wood surfaces by glow discharge plasma. Wood Sci Technol 45:169\u0026ndash;182. https://doi.org/10.1007/s00226-010-0317-7 \u003c/li\u003e\n\u003cli\u003eKim TH, Kim M, Lee W, Kim H-G, Lim C-S, Seo B (2019) Synthesis and characterization of a polyurethane phase separated to nano size in an epoxy polymer. 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Wood Sci Technol 55:295\u0026ndash;313. https://doi.org/10.1007/s00226-020-01258-2 \u003c/li\u003e\n\u003cli\u003eOdr\u0026aacute;\u0026scaron;kov\u0026aacute; M, R\u0026aacute;hel\u0026rsquo; J, Zahoranov\u0026aacute; A, Tino R, Cern\u0026aacute;k M (2008) Plasma activation of wood surface by diffuse coplanar surface barrier discharge. Plasma Chem Plasma Process 28:203\u0026ndash;211. https://doi.org/10.1007/s11090-007-9117-8 \u003c/li\u003e\n\u003cli\u003ePetric M (2013) Surface modification of wood. Rev Adhes Adhes 1:216\u0026ndash;247. https://doi.org/10.7569/RAA.2013.097308 \u003c/li\u003e\n\u003cli\u003ePittaway MD (2023) Towards more sustainable materials for boat decking: Novel fillers for light-weighting and enhanced recyclability. 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Holzforschung 72:979\u0026ndash;991. https://doi.org/10.1515/hf-2017-0207 \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"cellulose","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cels","sideBox":"Learn more about [Cellulose](https://www.springer.com/journal/10570)","snPcode":"10570","submissionUrl":"https://submission.nature.com/new-submission/10570/3","title":"Cellulose","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"DCSBD plasma, degreasing, wood coatings, artificial ageing","lastPublishedDoi":"10.21203/rs.3.rs-7259572/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7259572/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn recent years, research has focused on eco-friendly techniques to find alternatives to traditional methods to reduce environmental impact. This paper examines three wood degreasing methods and their impact on two different wood coatings. Conventionally used turpentine and petroleum-based solvents were compared with diffuse coplanar surface barrier discharge plasma treatment for degreasing soft and hardwoods. The effect of plasma degreasing technique was tested on an antifouling paint (both with and without epoxy primer) and on a polyurethane varnish made from a modified alkyd resin. To evaluate degreasing methods on varnishes over time, accelerated artificial ageing was conducted for 240 hours. Gloss, colour, and ATR FT-IR measurements were taken for evaluation. All samples showed darkening and a loss of gloss after undergoing artificial weathering, with the most significant colour changes observed within the first 120 hours. ATR FT-IR analysis indicated no significant differences in the coatings based on the degreasing method used. This confirms that plasma degreasing is just as effective as traditional methods and does not notably affect the appearance of the coating.\u003c/p\u003e","manuscriptTitle":"DCSBD Plasma Treatment as an Alternative to Commercial Surface Degreasing Agents Before Applying Wood Coatings","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-02 13:39:46","doi":"10.21203/rs.3.rs-7259572/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-20T21:53:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-20T21:31:30+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-01T02:17:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"Cellulose","date":"2025-07-31T07:55:41+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"cellulose","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cels","sideBox":"Learn more about [Cellulose](https://www.springer.com/journal/10570)","snPcode":"10570","submissionUrl":"https://submission.nature.com/new-submission/10570/3","title":"Cellulose","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6ba217f2-f8e1-45c1-a945-225f1a29625c","owner":[],"postedDate":"September 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T16:09:57+00:00","versionOfRecord":{"articleIdentity":"rs-7259572","link":"https://doi.org/10.1007/s10570-026-07041-z","journal":{"identity":"cellulose","isVorOnly":false,"title":"Cellulose"},"publishedOn":"2026-04-19 15:57:41","publishedOnDateReadable":"April 19th, 2026"},"versionCreatedAt":"2025-09-02 13:39:46","video":"","vorDoi":"10.1007/s10570-026-07041-z","vorDoiUrl":"https://doi.org/10.1007/s10570-026-07041-z","workflowStages":[]},"version":"v1","identity":"rs-7259572","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7259572","identity":"rs-7259572","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}