Mohammad Farsi

The study aimed at investigating the impact of Microwave Heat Treatment (MHT) on the physical and mechanical properties of wood flour (WF)/Nano-SiO₂/High-Density polyethylene composites by varying Nano-SiO₂ loading from 0, 1, 2, and 3% wt with a constant WF loading at 50% wt. By milling the materials in which were firstly mixed in a twin-screw extruder (Brabender® Plasti-Corder®), wood-plastic composites ASTM Standard samples were produced by an injection molding machine. Microwave irradiation with a power of 900 W and a temperature of 85°C for 7 min was applied for post-treatment of WPCs. After applying the microwave treatment, samples were subjected to physical and mechanical tests. The results indicated that increased Nano-SiO₂ loading up to 3 wt% led to increasing the flexural strength and modulus while decreasing the impact resistance, water absorption, and thickness swelling of samples. As such, morphological analyses revealed that MHT increased the flexural modulus and strength, as well as, decreased the impact strength, water adsorption, and thickness swelling of the samples.

This study aimed at producing the biodegradable composite from lignocellulose nanofibers (LCNFs) and Pebax^® thermoplastic elastomer. For this purpose, LCNFs at different levels of 0, 1, 3, and 5% were considered. The LCNFs were prepared by benzyl alcohol and then mixed with Pebax^®. The liquid phase of the LCNFs and soluble polymer was prepared and then the masterbatches were mixed in an internal mixer (Model 815802, Brabender, Germany). The mixtures from the internal mixer were put into a hot press and test samples were compress-molded. The physical properties results indicated that water absorption and thickness swelling decreased by the addition of more amount of LCNF. By the addition of LCNFs to polymer, the tensile strength and modulus and impact strength were increased compared to samples without LCNF. No regular trend of enthalpy changes was observed as the content of LCNF changed. When the LCNF concentration was increased to 5%, the crystallization temperature was increased. As the LCNF concentration increased to 3%, the glass transition temperature ( T_g) was decreased, whereas by incorporating more LCNFs, the T_g was increased. The result of the Fourier transform infrared spectra showed the peaks at 1740 cm⁻¹ which indicated the presence of polyamide bonds. Also, new peaks were observed in the range of 1400–1500 cm⁻¹ that was probably related to the presence of C−C bonds of glucose at LCNFs chains.

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.

Persian ironwood (Parrotia persica) is native species from Iran and covers 10,54% of the commercial volume. Its wood structure and its chemical composition are affected by growth conditions. The aim of the studywas to assess the variation of mineral content (Ni, Fe, Cu, Zn, Pb, Cd), wood density and chemical properties (cellulose, lignin, ash and extractive) of ironwood in relation to altitude above sea level (100, 500 and 700meter) and pith distance within stem (near to pith and bark and middle point). In addition was investigate the relationship between mineral content with oven-dried density and chemical properties. Results showed that Cd, Cu, Fe, Ni and Zn content (except Pb concentration) increased by increasing of altitude and decreased along radial position within stem from the pith to the bark. Lignin, ash and extractive content increased byincreasing altitudes from 100 to 700 meter while cellulose decreased. Radial position had not significant impact on the chemical properties. There are significant relationships between mineral content–chemical properties and between mineral content-wood density (except Cu - density). Forward stepwise regression showed that ash and lignin content had important role on the variation of all of mineral content except on Cd.