Ahmed A. Ahmed

Alginate is a biological substance with a wide range of uses in engineering and the biological sciences. Its exceptional qualities, namely its excellent biocompatibility and simple gelling, make it widely employed. Numerous cross-linking methods, for example, can be used to create alginate hydrogels. Their structural similarity to extracellular matrices present in living tissues makes them highly useful for wound healing as well as the administration of chemical medicines, tiny proteins, and transplanted cells. Alginate is also frequently employed in a variety of technologies, such as tissue engineering cell transplantation and different biomolecule immobilization techniques. This study will address the main features of alginate and hydrogels, their biological functions, and new ways to research with these polymers in the future.

Objectives. Exposure to ultraviolet (UV) radiation initiates a photo-oxidative degradation process in plastics that causes broken chemical bonds, weight loss, and weakened crosslinking, as well as the formation of free radicals and release of volatile substances. The work aims to study the influence of UV radiation on polystyrene films containing low concentrations of highly aromatic Schiff bases.Methods. Utilizing the described casting technique, polystyrene films containing a small quantity of strong highly aromatic Schiff bases were produced. These films were then subjected to 300 h of UV irradiation. Following irradiation, analyses were conducted on the infrared spectra, weight loss, and surface morphology of the polystyrene.Results. The surface of the sheets was initially smooth and free of wrinkles. However, following irradiation, remarkable morphological changes were observed as the surface became more uneven. Intentional perforations and imperfections introduced into the examined surfaces were used to indicate the degradation of the polymer matrices.Conclusions. Highly aromatic Schiff bases act as photostabilizers to significantly reduce the extent of photodegradation in polystyrene films when compared to films with no additives.

Synthesis of tungsten oxide nanoparticles by alternative method has been use of environmentally friendly green methods that involve natural materials like plants, bacteria, fungi, solvothermal, microwave-assisted, biosynthesis, sonochemical, polysaccharides, seaweed, plant-derived materials, biodegradable polymers, and algae. using effective green chemistry to create nanoparticles has sparked a lot of attention lately due to its environmental friendly, simplicity, affordability, and clean technology. It also doesn't use any dangerous chemicals and produces no impurities or wastes. Plant extracts have garnered the greatest attention among these bio-entities due to their special natural qualities that enable them in a single production step to stabilize and decrease metal nanoparticles. The changes and future prospects of green synthesis methods using plant extracts, solvothermal, microwave-assisted, biosynthesis, and sonochemical processes for tungsten oxide nanoparticles are reviewed in this paper.

NiO nanoparticle synthesis by chemical method and characterized by XRD with crystal size 11.72 nm and grain size 13 nm from FESEM image also NiO micro used ,two NiO as an additive to evaluate the possibility of producing photodegradable polymers, the practical application of solid-phase photocatalytic degradation of polyvinyl chloride (PVC- NiO composite films) was investigated. PVC has a negative impact on the environment since its polymer degrades slowly, yet it has a wide range of industrial applications and the amount used shows no evidence of diminishing use. Thus, a synthesis of modified PVC- NiO micro and nano has been studied with 0, 50, 100, 150, 200, 250, and 300 (hours) as irradiation time and a number of spectroscopic analyses such as FTIR and UV-VIS. Additionally, the effects of adding nanostructures to PVC chains on optical stability testing procedures were examined through indices (ICO, IPO, and IOH), weight loss measurements, UV and viscosity.