Enhancing physico-mechanical and antibacterial properties of natural rubber using synthesized Ag-SiO2 nanoparticles.

The incorporation of the prepared Ag-SiO2 core-shell particles in natural rubber matrix was investigated on antibacterial and mechanical properties of resulting composites. Significant antibacterial effect against S. aureus (Gram positive) and P. aeruginosa (Gram negative) was observed and achieved inhibition growth up to 85 and 90%, respectively, after 24 h depending on the amount of Ag-SiO2 core-shell. It was found that SiO2 acted as crosslinking agent and controlling the amount of silver release. UV-vis spectra and TEM, XRD showed Ag-SiO2 core-shell particles formation. SEM, FTIR, XRD and mechanical analysis showed uniform distribution of Ag-SiO2 core-shell into rubber matrix with enhanced tensile strength.

Green, economic, and partially biodegradable wood plastic composites via enzymatic surface modification of lignocellulosic fibers.

Lignocellulosic fibers, which obtained from Citrus trees trimmings, were modified with Aspergillus flavus (EGYPTA5) enzymes. The non-modified and the modified lignocellulosic fibers were used with low density polyethylene (LDPE) by melt blending brabender method at 170 °C with different ratio (5, 10 and 20 wt%) to obtain wood plastic composites (WPC). The prepared samples were characterized using Fourier-transformed infrared (FT-IR), Scan Electron Microscope (SEM), and Water vapor transmission rate (WVTR) as well as, the mechanical, thermal, biodegradability and swelling properties were examined. The fabricated WPC displayed good mechanical and thermal properties compare with pure LDPE. Also, the WVTR was enhanced by the addition of modified lignocellulosic fibers over the unmodified one. Moreover, the enzymes assay such as cellulase and lignin peroxidase enzymes were estimated and confirming the growing of fungi on the lignocellulosic fiber in solid state fermentation condition to improve lignin peroxidase production and eliminate cellulose enzymes. The fabricated WPC can be used in different environmental application such as packaging system, that it will be green, economic, and partially biodegradable.