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The focus of this work is to develop the knowledge of prediction of the physical and chemical properties of processed linear low density polyethylene (LLDPE)/graphene nanoplatelets composites. Composites made from LLDPE reinforced with 1, 2, 4, 6, 8, and 10 wt% grade C graphene nanoplatelets (C-GNP) were processed in a twin screw extruder with three different screw speeds and feeder speeds (50, 100, and 150 rpm). These applied conditions are used to optimize the following properties: thermal conductivity, crystallization temperature, degradation temperature, and tensile strength while prediction of these properties was done through artificial neural network (ANN). The three first properties increased with increase in both screw speed and C-GNP content. The tensile strength reached a maximum value at 4 wt% C-GNP and a speed of 150 rpm as this represented the optimum condition for the stress transfer through the amorphous chains of the matrix to the C-GNP. ANN can be confidently used as a tool to predict the above material properties before investing in development programs and actual manufacturing, thus significantly saving money, time, and effort. [ABSTRACT FROM AUTHOR]

The introduction of self-healing functionality into epoxy matrix is an important and challenging topic. Various micro/nano containers loaded self-healing agents are developed and incorporated into epoxy matrix to impart self-healing ability. The current report reviews the major findings in the area of self-healing epoxy composites and coatings with special emphasis on these containers. The preparation and use of polymer micro/nano capsules, polymer fibers, hollow glass fibers/bubbles, inorganic nanotubes, inorganic meso- and nano-porous materials, carbon nanotubes etc. as self-healing containers are outlined. The nature of the container and its response to the external stimulations greatly influence the self-healing performance. The self-healing mechanism associated with each type of container and the role of container parameters on self-healing performance of self-healing epoxy systems are reviewed. Comparison of the efficiency offered by different types of containers is introduced. Finally, the selection of containers to develop cost effective and green self-healing systems are mentioned. [ABSTRACT FROM AUTHOR]

The aim of this study is to compare the graphene produced using a biotechnological method (Escherichia coli) with the graphene produced by Hummers’ method (a chemical method) and to study the effect on the energy consumption and environment. The results indicated that the chemical reduction process has higher energy consumption, approximately 1642 Wh, than the energy consumption of the biotechnological reduction process, which is 5 Wh. The potential of global warming (GWP 100) improved by 71% using the biotechnological route for the production of graphene. Abiotic depletion, the photochemical ozone creation potential, and marine aquatic ecotoxicity potential were improved when the biological route was employed, compared with the chemical route. The eutrophication potential, terrestrial ecotoxicity, and ozone depletion layer changed very little since the main variables involved in the production of graphene oxide and waste management are the same. The biotechnological method can be considered a green technique for the production of graphene, especially given the reduction in the negative effects on global warming, abiotic depletion, the photochemical ozone creation potential, and the marine aquatic ecotoxicity potential. [ABSTRACT FROM AUTHOR]