Mechanical Robustness of Metal Nanocomposites Rendered by Graphene Functionalization

Ultrastrong and Deformable Aluminum-Based Composite Nanolaminates with Transformable Binary Intergranular Films

Nanostructured metals with conventional grain boundaries or interfaces exhibit high strength yet usually poor ductility. Here we report an interface engineering strategy that breaks the strength-ductility dilemma via externally incorporating graphene oxide at lamella boundaries of aluminum (Al) nanolaminates. By forming the binary intergranular films where graphene oxide was sandwiched between two amorphous alumina layers, the Al-based composite nanolaminates achieved ultrahigh compressive strength (over 1 GPa) while retaining excellent plastic deformability. Complementing experimental results with molecular dynamics simulation efforts, the ultrahigh strength was interpreted by the strong blocking effect of the binary intergranular films on dislocation nucleation and propagation, and the excellent plasticity was found to originate from the stress/strain-induced crystalline-to-amorphous transition of graphene oxide and the synergistic deformation between Al nanolamellas and the binary intergranular films.

Unsaturated Polyester Resin Filled with Cementitious Materials: A Comprehensive Study of Filler Loading Impact on Mechanical Properties, Microstructure, and Water Absorption

In recent years, cheaply available cementitious materials (CMs) are increasingly finding useful applications in construction engineering. This manuscript focused on the development and fabrication of unsaturated polyester resin (UPR)/cementitious material composites to be potentially useful in a variety of construction applications. For this purpose, five types of powders from widely available fillers, i.e., black cement (BC), white cement (WC), plaster of Paris (POP), sand (S), and pit sand (PS), were used. Cement polymer composite (CPC) specimens were prepared by a conventional casting process with various filler contents of 10, 20, 30, and 40 wt %. Neat UPR and CPCs were investigated mechanically by testing their tensile, flexural, compressive, and impact properties. Electron microscopy analysis was used to analyze the relation between the microstructure and mechanical properties of CPCs. The assessment of water absorption was conducted. The highest tensile, flexural, compressive upper yield, and impact strength values were recorded for POP/UPR-10, WC/UPR-10, WC/UPR-40, and POP/UPR-20, respectively. The highest percentages of water absorption were found to be 6.202 and 5.07% for UPR/BC-10 and UPR/BC-20, while the lowest percentages were found to be 1.76 and 1.84% for UPR/S-10 and UPR/S-20, respectively. Based on the finding of this study, the properties of CPCs were found to depend on not only the filler content but also the distribution, particle size, and combination between the filler and the polymer.

Applications of Graphene in Five Senses, Nervous System, and Artificial Muscles

Graphene remains of great interest in biomedical applications because of biocompatibility. Diseases relating to human senses interfere with life satisfaction and happiness. Therefore, the restoration by artificial organs or sensory devices may bring a bright future by the recovery of senses in patients. In this review, we update the most recent progress in graphene based sensors for mimicking human senses such as artificial retina for image sensors, artificial eardrums, gas sensors, chemical sensors, and tactile sensors. The brain-like processors are discussed based on conventional transistors as well as memristor related neuromorphic computing. The brain-machine interface is introduced for providing a single pathway. Besides, the artificial muscles based on graphene are summarized in the means of actuators in order to react to the physical world. Future opportunities remain for elevating the performances of human-like sensors and their clinical applications.