The potential usage of virgin Low density polyethelyne (LDPE) reinforced with different concentrations (2%, 5% and 6% by weight) of treated rice straw with different lengths (2 mm, 4 mm and 6 mm) is investigated to produce high value products that have technical and environmental demand. The two treatment methods used for rice straw are alkali and acidic treatments of rice straw. The removal of impurities and waxy substances from fiber surface avoid creation of rougher topography after treatment and improves the quality of fiber, also content of hemi cellulose and lignin decrease so increase effectiveness of fiber due to dispersing of fiber in matrix. The reinforcing material is embedded in the matrix material to enhance tensile and flexural behaviors of the synthesized composite. The result of investigating these two mechanical properties, using statistical analysis & design of experiments, showed an enhancement in the mechaniccal properties of the virgin polymer composite compared to the virgin polymer. The flexural stress of the composite increased three times the virgin flexural stress, while the tensile stress increased eight times the original tensile stress
Ciprofloxacin (CIP) antibiotic was loaded on silver nanoparticles (AgNPs), which were prepared by three different methods to enhance their antibacterial activity against Gram-negative (Escherichia coli) bacteria and Gram-positive (Staphylococcus aureus) bacteria. AgNPs were prepared by using sodium borohydride (NaBH4), lactose and sodium citrate followed by one-year aging, in order to produce a uniform prism shape. Finally, the synthesized AgNPs were functionalized with CIP to form composite of AgNPs-CIP. Various analytical techniques were used to characterize the prepared nanocomposites such as ultraviolet-visible (UV-Vis) absorption spectra, Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM). TEM images showed some differences in average particle size of AgNPs and their distribution according to the preparation methods. Disc diffusion method was used to investigate the antibacterial activity of AgNPs-CIP composites. Results showed a significant improvement in antibacterial activity against both classes of bacteria especially for the prism AgNPs-CIP. Owing to nanoprisms vertexes and edges which facilities the penetration of Ag ions into the cell wall. AgNPs-CIP composites exhibited higher antibacterial activity against Gram-positive than Gram-negative bacteria due to the differences in bacteria cell walls compositions between the two types.
ARTICLE HISTORY
This paper aims to conduct a feasibility study of producing fuel from plastic waste. It is a suggested approach to deal with the huge production of synthetic plastic around the world, so as to avoid its accumulation in landfills and the depletion of resources. Several types of research have addressed the conversion of plastic waste into energy, and in this study the authors focused on using pyrolysis to convert plastic to liquid oil. Accordingly, the volume of the waste was reduced significantly, and the produced liquid oil had a high calorific value in comparison to fossil fuel. The authors managed to develop a profitable business model for a facility producing fuel from plastic waste in Egypt. This project could be a very lucrative business opportunity for investors or venture capitalists interested in investing in green economy. A Business Model Canvas was used as a tool to identify how the different components of the business relate to each other.
Chitosan (CS) nanocomposite mesoporous membranes were fabricated by mixing CS with graphene (G) and fullerene (F) nanofillers, and the diffusion properties through CS membranes were studied. In addition, in order to enhance the binding between the internal CS chains, physical cross-linking of CS by sodium tripolyphosphate (TPP) was carried out. F and G with different weight percentages (0.1, 0.5, and 1 wt.%) were added on physically cross-linked chitosan (CLCS) and non-cross-linked chitosan (NCLCS) membranes by wet mixing. Permeability and diffusion time of CLCS and NCLCS membranes at different temperatures were investigated. The results revealed that the pore size of all fabricated CS membranes is in the mesoporous range (i.e., 2–50 nm). Moreover, the addition of G and F nanofillers to CLCS and NCLCS solutions aided in controlling the CS membranes’ pore size and was found to enhance the barrier effect of the CS membranes either by blocking the internal pores or decreasing the pore size. These results illustrate the significant possibility of controlling the pore size of CS membranes by cross-linking and more importantly the careful selection of nanofillers and their percentage within the CS membranes. Controlling the pore size of CS membranes is a fundamental factor in packaging applications and membrane technology.
Chitosan nanocomposite thin films were fabricated using two types of chitosan natural polymer (cross-linked chitosan (CLCS) and non-cross-linked chitosan (NCLCS)), with three different weight percentages nano-fillers (Graphene (G) and fullerene (F)). Nanoindentation tests were performed to investigate the local mechanical properties of the produced nanocomposite in comparison to the unreinforced chitosan thin films. Nano hardness values (H) and indentation modulus (E) were measured using 5 and 10 µm spherical indenters. The addition of nano fillers enhanced the hardness of both types of films with the amount of hardening being directly proportional to the fraction of nano filler added(p<0.001). Crosslinking has also significantly increased the hardness (p< 0.001). The larger indentation returned a lower hardness. The use of different radii nano indenters underlined the indenter size effect due to the differing strain fields. The promising mechanical properties resulting from this research will allow using the fabricated nanocomposites for tissue engineering, biomedicine, drug delivery, electronics, energy, surface coatings and packaging applications.
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