A. Kübra Yontar et al.
Inorganic Chemistry Communications 159 (2024) 111865
was measured after incubation for 24 h at 37 ◦ C. The growth difference between the culture treated with coated filters and the positive control was assessed logarithmically and documented. 3. Results and discussion 3.1. Characterizations of silver nanoparticles UV – Vis spectroscopy has been utilized to clarify the optical proper ties and demonstrate the generation of AgNPs after green synthesis. Fig. 3 (A) demonstrates that the most intense wavelength for silver nanoparticles is around 415 nm, 72 h after green synthesize. The peak observed in the UV – Visible spectrum is strongly affected by the size, shape, and morphology of the created AgNP. Earlier studies has shown that the visible zone of spherical-shaped AgNP fluctuates in wavelength with amplitude from 400 to 470 nm under UV – Visible spectroscopy [39 – 44]. The varying sizes and shapes of AgNP cause a wide range of absorption bands to appear. Average sizes and standard derivation values of silver nanoparticles produced by green synthesis are shown in the graph given in Fig. 3 (B). The average nanoparticle size and standard deviation were found to be 45 nm and 1.59 nm, respectively. UV – Vis spectroscopy and particle size measurement analyzes revealed that nano silver particles could be successfully synthesized in small sizes. 3.2. X-ray diffraction analysis of MDF surfaces Crystal phases, nature and average crystal size values of MDF coating surfaces were measured and calculated by XRD analysis. In particular, XRD revealed the crystal structure of AgNP synthesized with Cannabis Sativa seed extracts and polymeric coating material in Fig. 3. XRD pattern of MDF surfaces revealed the sharp diffraction peaks at 30.68 ◦ , 36 ◦ , 43.62 ◦ , and 63.18 ◦ , indexed as (220), (311), (200) and, (220) Bragg ’ s reflection planes. These peaks correspond to FCC lattice struc ture and crystalline nature as indexed in JCPDS-04 – 0783 [45,46]. This crystal structure of our AgNPs parallels the XRD pattern of silver nanoparticles synthesized from plant extract in similar studies [47 – 52]. The unassigned peaks were considered to have formed because of the crystallization of other organic compounds in the Cannabis Sativa seeds extract. The wide-ranging main crystal peaks appearing at 23 ◦ are pre dicted to arise mainly from the coating resin and added cross-linkers, and these peaks have also been revealed in similar studies [53 – 55]. Debye-Scherrer formula (1) was used to calculate the crystallite size on MDF surfaces containing synthesized green AgNPs. Calculation of crystallite size of all samples was based on the four strongest peaks observed in the XRD pattern. The crystallite size was found to be 12.26, 9.58 and 6.13 nm for samples A, B and C, respectively. Crystallite size is known to belong to a consistently diffracted area and does not have the same meaning as particle size [56,57]. The lowest crystallite sizes in sample C, which contains the highest amount of AgNP, are due to nanoparticles. It was calculated that the crystallite size decreased with increasing AgNP content. The addition of AgNP suppresses the growth of polymer particles in the melamine resin present in the MDF coating. Thus, it creates a retarding effect that reduces the crystallite size. Moreover, reducing the crystallite size leads to an increase in the surface area, which improves the antibacterial effect. The higher polymer ratio in the coating content causes the polymer grains and crystals to grow rapidly upon cooling and the crystallite sizes to increase [58 – 61]. 3.3. Microstructural characterzation of MDF surfaces SEM analysis was performed to examine the nanosilver distribution on the coating surfaces. Fig. 4 shows the microstructure images of the MDF sample without any coating and the MDF coating surfaces modified with nanosilver. Fig. 4 (R) shows the surface of an uncoated MDF sample. Fig. 4 (A), (B) and (C) show the microstructures of the coating surfaces containing 1 %, 3 % and 5 % nanosilver. Fig. 4 (D) shows the
Table 1 Stain resistance of nanosilver modified MDF coatings. AgNP Modified MDF Samples Stain resistance 1 % Outdoor (in contact with oxygen)
Closed to external environment (no contact with oxygen)
Vinegar (Suitable) Acetone (Suitable) Coffee (Suitable) Bleach (Suitable) H 2 O 2 Suitable (Slight discoloration) Vinegar (Suitable) Acetone (Suitable) Coffee (Suitable) Bleach (Suitable) H 2 O 2 Suitable (Slight discoloration) Vinegar (Suitable) (Light Stain) Acetone (Suitable) Bleach (Suitable) Coffee (Suitable) H 2 O 2 (Suitable)
Vinegar (Suitable) Acetone (Suitable) Coffee (Suitable) Bleach (Suitable) H 2 O 3 (Suitable) Vinegar (Suitable) Acetone (Suitable) Coffee (Suitable)
3 %
Bleach (Suitable) (Light Stain)
H 2 O 3 (Suitable)
5 %
Vinegar (Suitable) Acetone (Suitable) Bleach (Suitable) Coffee (Suitable) H 2 O 3 (Suitable)
Table 2 Wear, scratch resistance and curing times of nanosilver modified MDF surface coatings. Agnps Gel Time (Curing Time)
Abrasion Resistance ( ˙ Ip + Fp)/2 ( > 150)
Scratch Resistance ( > 1.75 N)
Modified Samples (%)
Cycle
N
1st Bath Melamine, Formaldehyde
2nd Bath
%1
275
3
Glue And Hardener
Control Sample: 3 Minutes 42 Seconds Agnps Modified: 3 Minutes 32 Seconds Control Sample: 3 Minutes 40 Seconds Agnps Modified: 3 Minutes 33 Seconds Control Sample: 3 Minutes 43 Seconds Agnps Modified: 3 Minutes
Control Sample: 3 Minutes 16 Seconds Agnps Modified: 1 Minute 53 Seconds Control Sample: 3 Minutes 18 Seconds Agnps Modified: 1 Minute 40 Seconds Control Sample: 3 Minutes 15 Seconds Agnps Modified: 1 Minute 20 Seconds
%3
250
3
%5
165
3
edge section of the MDF sample. The layer on the top layer is the coating consisting of paper, resin and nanosilver particles applied to the MDF surface. EDS analysis was performed to determine the coating content and nanosilver presence on the coating surfaces . Fig. 5 shows the results of the EDS mapping analyses. Fig. 5 (R) shows the EDS mapping of the uncoated MDF surface, and Fig. 5 (A), (B), and (C) of the AgNP modified coating surfaces. The elements present on the surfaces are shown sepa rately for the regions they are found in the mapping results with different colors. EDS results of the sample without coating revealed that
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