A nanocrystalline porous silicon (PS) layer was prepared by electrochemical etching method of p-type silicon wafer in hydrofluoric acid (HF). The properties of porous silicon structure under various etching times (10-50 min), HF concentrations, and current density were studied. The study included photoluminescence (PL), morphology, x-ray, and gas sensor. The results (PL) spectra (peak wavelength) can be shifted from (505 to 625) nm. PL analysis indicated that the energy band gap can be tuned from (1.984-2.455) eV with respect to etched time. Atomic Force Microscopy (AFM) analysis showed that the PS layer had a sponge-like structure. Surface roughness and the pyramid-like hillocks on the entire surface play an important role in variation visible luminescence. The AFM images shows that the average diameter of the PS layer pore and thickness the Silicon decreased when etching time increase and the average diameter particleboard ranged from (80.8-35.4) nm. PS X-ray topography studies that the skeleton maintained its silicon crystalline structure after anodization. PS Sensors were fabricated and tested successfully on H 2 and No 2 gas.

Study of the mechanical properties of polymer blend composite to the preparation of matrix Unsaturated Polyester resin (UPS) with natural rubber (NR) and polymethyl methacrylate (UPS:NR:PMMA) material and study influence Nano Yttrium Oxide (Y2O3) on the composite . The first group is the preparation of samples of the mixture of polyester matrix with natural rubber material in ratio certain, It was examined the mechanical properties: tensile, flexure at break, young modules, hardness and compression decreases with increases the natural Rubber ratio but Elongation test increases when increases Rubber ratio. The second group is the samples preparation of the mixture of polyester with PMMA material, test mechanical properties decreases with increases the PMMA ratio. Third group was prepared from a mixture of polymer blend composite, which consists of fixed ratios of polyester, natural rubber and PMMA. Addition of Nano material Y2O3 at ratio (0.25-1.5) wt% .result test mechanical properties increases with increases the Y2O3 ratio.

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Particles of waste from plastic medical syringes (WPMS) are recycled with a polymeric adhesive from unsaturated polyester resin (UPS) to manufacture structural profiles at the lowest cost, and that could be used in various applications such as buildings, furniture manufacturing, toys, etc. The manual molding method was used in preparing the models for testing with the following volumetric fractions (0%, 30%, 40%, 50%, 60%, 70%, 80%), and with a granular size of (0.45mm) of WPMS). Some tests were performed on the prepared samples, including mechanical ones, tests included are (tensile test, bending test, and hardness test), in addition to the physical test, which is (thermal conductivity),The results of the mechanical tests showed an increase in the values of mechanical properties of (tensile strength, the flexural modulus, and hardness) as the volumetric ratios of (WPMS) particles increased. Whereas, the thermal conductivity values decreased as the volumetric ratios of (WPMS) particles increased. Given that this is the first time that this type of waste is used in manufacturing structural profiles at a low-cost in exchange for less harms to the environment. Keywords: Waste, Recycling, low-cost structures, plastic syringes, unsaturated polyester adhesive.

The degradation of waste plastics in the environment is such an essential issue for Earth protection. This study indicated the importance of using waste bottles to produce recycled depolymerization Polyethylene Terephthalate (DPET). The bubble column reactor technique and its effect in the depolymerization process have been investigated. The DPET with Poly-methyl methacrylate (PMMA) has been used to fabricate the hybrid polymer to improve the mechanical properties. Thus, different percentages (1, 2, 3, 5, and 10 %) of (DPET) are used to surmise its repercussions on the mechanical properties of the polymer. These ramifications were studied through a sequence of research laboratory tests, including tensile strength, Charpy impact, and shore-D hardness, and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The results show a development interest, especially for impact strength and surface hardness, where both tests show compatible results, especially at (10%) of DPET. At the same time, maximum results of tensile strength are at (3%). FTIR analysis shows a chemical reaction between DPET and PMMA, which significantly improves the characteristics and makes it a wide range of available applications.