Nano Hybrids and Composites Vol. 47

Abstract: The basic task of packaging is to protect the product from mechanical, physicochemical and biological changes. Inappropriate material and incorrectly selected packaging can significantly affect the qualitative characteristics of the product as well as the shelf life of the packaged content. Packaging materials are chosen based on the characteristics of the product to be packaged, the intended packaging procedure, and the required shelf life of the product. The strictest requirements apply to packaging materials for food and pharmaceutical products. Polymeric materials are used as monomaterials or in combination with other materials. This paper will present the results of testing polymer materials used for the production of food products. Among the characteristics, the results of tests of elongation at break and tensile strength will be presented. The investigated materials were polymer films produced by the coextrusion process (PE/PA/PE and PP/PA/PP) and polymer materials for the production of glasses for dairy products (polystyrene tape, polypropylene compound tape and polypropylene tape with a barrier layer).

Abstract: The research focused on investigating the physical and mechanical properties of stretch films containing recycled materials. The objective of the study was to examine how the use of recycled materials affects the structure and physical and mechanical properties of 5-layer stretch films. The results showed that incorporating up to 50% recycled materials in the stretch films can be a viable option for securing containers on pallets, provided that the film's composition is appropriately modelled using specific primary polymers in the film layers. The study employed extrusion methods to create the stretch films.

Abstract: Polylactic acid (PLA) has become a promising material for medical implants due to its biocompatibility, biodegradability, and favorable mechanical properties. With advancements in Fused Deposition Modeling (FDM) 3D printing technology, it is possible to further optimize the performance of PLA by adjusting printing parameters. This optimization is crucial for enhancing the energy absorption and durability of PLA, especially in applications like medical implants that require reliable mechanical strength. This study utilized Response Surface Methodology (RSM) with the Box-Behnken Design (BBD) to investigate the effects of key FDM 3D printing parameters—layer thickness, infill pattern, and infill density—on the energy absorption and durability of PLA. A total of 15 experiments were conducted, with each factor tested at three levels. The standard Charpy impact test (ISO 179) was used to measure energy absorption in samples of dimensions 80x10x4 mm. This research aims to identify the key FDM 3D printing parameters that maximize the energy absorption and durability of polylactic acid (PLA) for use in medical implants, leveraging PLA's biocompatibility and mechanical properties. The study found that infill density and infill pattern are the two most critical factors affecting the energy absorption and durability of PLA. An infill density of 80% was determined to be optimal, as higher densities significantly improved energy absorption. Additionally, the grid infill pattern, combined with the highest layer thickness of 0.3 mm, provided the best performance. In conclusion, these findings offer valuable insights for optimizing PLA in medical implant applications, with potential for further refinement based on specific use cases.

Abstract: The present work includes an investigation of the effect of α-alumina nanoparticles addition to aluminum-based nanocomposites on its mechanical properties and finding the optimal value of alumina nanoparticles that give the best properties. Experimental work includes manufacturing samples of aluminum-based nanocomposite reinforced with alumina nanoparticles by powder metallurgy- hot forging process. Mechanical properties were tested. The results show an increase in hardness and compression yield strength with increasing the weight percentage of alumina nanoparticles, while the wear rate decreased to certain percentages of addition and then increased again. From the experimental results, multiple regression analysis methods have been used to obtain an empirical equation for predicting the mechanical properties and describe the behavior of hardness, compression strength, and wear rate. Genetic Algorithm Optimization was applied to find the optimum value of alumina nanoparticles weight percentage which gives good mechanical properties.

Abstract: A new set of nanocrystals of carbon nanospheres (5%, 10%, and 15% by weight) were synthesized and were anchored to cobalt based metal-organic frameworks (Co-MOFs). They were synthesized using the organic linker, 4-{[(1E)-1-hydroxy-3-oxoprop-1-en-2-yl]sulfanyl}benzoic acid (4-HSPBA) via solvothermal synthesis. The synthesized materials were characterized for structural and morphological properties by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) surface area analysis. The electrochemical characteristics of the obtained Co-MOFs and carbon nanosphere-contained Co-MOF nanocomposites were investigated comprehensively by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The EIS tests revealed the characteristic current-voltage properties of pristine Co-MOFs and carbon nanosphere-doped Co-MOFs. While the undoped Co-MOF exhibited nearly linear current-voltage behavior, introduction of carbon nanospheres at increasing concentrations (5 wt.%, 10 wt.%, and 15 wt.%) resulted in very high non-linearity in the current-voltage response. The reason for non-linearity is a synergistic effect between carbon nanospheres and the Co-MOF matrix, which greatly influences the transport pathways for charges and enhances electrical conductivity. Further, morphological analysis confirmed the formation of heterostructured architectures with spherical shapes of uniform nature irrespective of doping level. The findings reveal the carbon nanosphere-modified Co-MOFs as promising electrode materials for supercapacitors with improved electrochemical attributes. Besides energy storage applications, the nanostructured materials are poised to revolutionize photonics, optoelectronics, and other emerging next-generation energy-related technologies.