A. Kübra Yontar et al.
Inorganic Chemistry Communications 159 (2024) 111865
Fig. 6. MDF surface images after performance tests, (A) MDF surface before tests, (B) application of stain resistance tests, (C) surface after stain resistance tests, (D) surfaces after wear test and, (E) furfaces after scratch test.
it contained C, O, Ca and K elements coming from the structure of the wood and binders used in MDF production. It is known that the Pd element comes from the coating applied to the sample to provide con ductivity for SEM imaging. In addition, it can be seen from the SEM image that the R sample does not contain nano silver and melamine resin added coating. In Fig. 4 (A), (B) and (C) images, the coating surface applied to the MDF surface under high temperature pressure and the nano silver particles dispersed on the surface are clearly visible. It is shown in Fig. 5 (A), (B) and (C) EDS results that the added nano silver particles are distributed homogeneously on all MDF surfaces. It is esti mated that the N, Fe, Si, Al and Ti elements appearing in the EDS mapping results come from the melamine resin coating content and the plants used in nano silver synthesis [62,63]. The image of the MDF coating layer in Fig. 4 (D) shows that the total veneer thickness is 1 mm. This layer is the layer containing paper, melamine and nano silver. 3.4. Performance tests The results of performance tests of silver nanoparticle treated and non-treated MDF surfaces are shown in Tables 1 and 2 . Staining resis tance tests were carried out both in an open air environment with ox ygen and in a vacuum environment with no contact with oxygen. The resistance of the surfaces to staining with different contaminants has
been tested and Table 1 shows their status against each contaminant. Whether the contaminants are suitable for the stains they leave on the surface or whether they are stained is also recorded. Fig. 6 (A) shows the coating surfaces before the staining test. In Fig. 6 (B) , the application of the staining tests is shown, and in Fig. 6 (C) , the surfaces are shown separately for each pollutant after the staining test. The slightly light gray areas visible on all post-test surfaces are not due to staining, but due to the reflection of light from rough surfaces with the nano silver ad ditive. After the staining test, it was determined that the nano silver treated surfaces were only slightly sensitive to hydrogen peroxide, bleach and vinegar. These staining amounts are at negligible levels. This result proved that nano silver reinforcement does not reduce the resis tance of the coating against different pollutants and chemicals. In order to examine the effects of nanosilver on the mechanical strength of MDF coating surfaces, abrasion and scratch tests were carried out and the results are shown in Table 2. According to TSE EN 438 – 2 standards, the control values are 150 cycles for wear resistance and 1.75 N for scratch resistance. Performance test results were compared according to these values. It has been determined that silver nanoparticle reinforcement increases the mechanical strength of all MDF coating surfaces above their standard values. However, sample A with 1 % AgNP added showed the highest wear resistance with 275 cycles. It has a wear resistance almost twice the standard value. As the nanoparticle ratio increased,
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