ABSTRACT
Contact infection of bacteria and viruses has been a critical threat to human health. The worldwide outbreak of COVID-19 put forward urgent requirements for the research and development of the self-antibacterial materials, especially the antibacterial alloys. Based on the concept of high-entropy alloys, the present work designed and prepared a novel Co0.4FeCr0.9Cu0.3 antibacterial high-entropy alloy with superior antibacterial properties without intricate or rigorous annealing processes, which outperform the antibacterial stainless steels. The antibacterial tests presented a 99.97% antibacterial rate against Escherichia coli and a 99.96% antibacterial rate against Staphylococcus aureus after 24 h. In contrast, the classic antibacterial copper-bearing stainless steel only performed the 71.50% and 80.84% antibacterial rate, respectively. The results of the reactive oxygen species analysis indicated that the copper ion release and the immediate contact with copper-rich phase had a synergistic effect in enhancing antibacterial properties. Moreover, this alloy exhibited excellent corrosion resistance when compared with the classic antibacterial stainless steels, and the compression test indicated the yield strength of the alloy was 1015 MPa. These findings generate fresh insights into guiding the designs of structure-function-integrated antibacterial alloys.
ABSTRACT
Since 2020, with the global spread of major respiratory infectious diseases, such as COVID–19, the demand and consumption of personal protective equipment, such as masks, have increased dramatically worldwide. The environmental pollution caused by numerous waste disposable face masks has gradually attracted people's attention. In this study, the mechanical properties of mask–chip–reinforced soil are evaluated from a new perspective, through the uniaxial, biaxial, conventional triaxial, and true triaxial compression tests on reshaped sandy soil samples mixed with different contents of mask chips. The experimental results show that the mechanical properties of the sandy soil can be improved by the mask chips. With the proper content of mask chips, the failure strength is substantially improved, and the failure of soil is delayed. Meanwhile, the strength and stiffness are significantly affected by the stress path and the content of mask chips, even if the soil samples with the same mask–chip content can also show different mechanical properties under different stress paths. Additionally, the mechanical properties of soil are not necessarily improved constantly with the increasing content of mask chips. The failure strength of sandy soil samples under conventional and true triaxial stress paths decreases when the mass content of mask chips exceeds 0.3% and 0.5%, respectively. This study confirms the potential of mask chips applied to subgrade, slope, and other engineering construction fields in a sustainable way. © 2023 by the authors.
ABSTRACT
The COVID-19 outbreak has led to the overproduction of meltblown fabrics commonly used in personal protective equipment such as face mask. Moreover, the yield ofconventional fabrication methods for meltblown fabrics have poor mechanical properties and lack accessional value and functional applicability. In this study, a short and highly efficient process was employed to produce polypropylene/polypyrrole (PPy) meltblown nanoyarn (PPMNY). The mechanical properties were improved by utilizing a helical structure, and the conductivity was enabled using a combination of PPy nanoparticles. The breaking force of the proposed PPMNY was as high as 10.1cN/tex at 9T/10 cm, nearly 3.3 times more than PPMNY without the helical structure. The breaking force of the proposed PPMNY was unaffected by the washing process, and the frictional properties and snarling information were similarly maintained by the helical structure. Additionally, the optimal conductivity of the proposed PPMNY reached 0.044S·m-1. Therefore, the novel methods investigated in this study can improve the properties of meltblown fabrics to yield a highly efficient and low-cost technique to produce conductive PPMNY. This concept can be extended for solving the problems of the single two-dimensional structure with poor mechanical properties and application on Smart Wearable with preferable conductivity. © Textile Bioengineering and Informatics Symposium Proceedings 2022 - 15th Textile Bioengineering and Informatics Symposium, TBIS 2022.