A novel approach for enhancing the color and antimicrobial properties of pine and beech wood using Se-NPs

Abstract

Pine wood (PW) and beech wood (BW) are the most used wood in furniture and other applications owing to their unique characteristics and low machining cost. However, their biodegradability and varied moisture content limit their wider use and durability. Therefore, in this study, nanotechnology was used as a novel eco-friendly approach to enhance the durability, antimicrobial properties, and color of wood. Selenium nanoparticles (Se-NPs) were prepared in spherical shape at varied concentrations (25 and 50 mM) using an eco-friendly method in the range of 35-80 and 40-155 nm, respectively. Se-NPs formation at the nanoscale was confirmed using UV/Vis analysis, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The prepared Se-NPs were then impregnated into PW and BW for different periods ranging from 2 h to 1 week. The treated wood were then leached in distilled water for 14 days to eliminate excess Se-NPs from the wood surface. The treated wood surfaces were examined using energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). In addition, the depth of Se-NPs penetration into the treated wood at both tangential and radial sides was determined. Se-NPs impacts on the color properties, density, moisture content and antimicrobial activities of the treated wood were evaluated. PW treated with Se-NPs showed better antimicrobial and color characteristics than treated BW. PW samples immersed in 50 mM Se-NPs for 2 h showed the highest K/S values, whereas the highest antimicrobial values were obtained for those immersed at the same concentration for 2 days, and 1 week.

Figure 1

Schematic drawing of the impregnation process of PW and BW with Se-NPs.

Figure 2

TEM images of Se-NPs at different concentrations of (a,b) 25 mM and (c, d) 50 mM, and UV/Vis spectra of Se-NPs synthesized at various concentrations and sodium hydrogen selenite.

Figure 3

SEM images of untreated (a) PW, (b) BW, the treated (c) PW, (d) BW with 50 mM Se-NPs at transverse section, the treated (e) PW, (f) BW with 50 mM Se-NPs at tangential side, and (g, h) EDX spectra of treated PW and BW.

Figure 4

X-ray diffraction (XRD) spectra of (a) treated and untreated PW, and (b) treated and untreated BW comparing to Se-NPs spectrum.

Figure 5

Images of PW surfaces: (a) blank, (b) treated with 25 mM Se-NPs, (c) treated with 50 mM Se-NPs, BW surfaces: (d) blank, (e) treated with 25 mM Se-NPs, (f) treated with 50 mM Se-NPs, penetration of 50 mM Se-NPs in (g) PW and (h) BW treated with 50 mM Se-NPs at the radial section, and the effect of Se-NPs concentration and impregnation time on K/S values of (i) the treated PW, and (j) the treated BW at 360 nm.