With the serious impact of fossil fuels on the environment and the rapid development of the global economy, the development of clean and usable energy storage devices has become one of the most important themes of sustainable development in the world today. Supercapacitors, known as ultracapacitors, have been supposed to be one of the most promising candidates to meet the requirements of human sustainable development, due to their advantages such as high capacity, high power density, high charging/discharging speed, long cycle life, and low processing cost. However, the low energy density of supercapacitors limits their large-scale application. Therefore, it is of great significance to develop high energy density supercapacitors and use them as power sources for practical devices. Conductive polymer-based electrode materials have unique advantages such as high theoretical capacitance, good conductivity, and good flexibility, and have high potential in supercapacitors. The research on conductive polymer-based electrode materials has promoted the rapid development of the field of supercapacitors. This review summarizes recent research progress on conductive polymers (including polypyrrole, polyaniline, and polythiophene), conductive polymer-based binary composites, and conductive polymer-based ternary and quaternary composites for supercapacitor electrodes. Furthermore, a summary of the use of conductive polymer-based textiles and fibers for flexible supercapacitors is also presented, along with the current challenges and future perspectives for conductive polymer-based supercapacitors.
In this paper, bismuth oxide (Bi2O3) as the main functional powder, lead (Pb) and tantalum (Ta) as the metal additives, epoxy resin as the matrix and polyester–cotton blended woven fabric as the substrate, Bi2O3 coating nuclear radiation protection composite, Bi2O3/Pb coating nuclear radiation protection composite, and Bi2O3/Ta coating nuclear radiation protection composite with different process parameters were prepared. The cross-section scanning analysis and the influence factor analysis of γ-ray protection performance were carried out, and the mechanical properties of the composites were discussed. The results show that an increase in Bi2O3 content (mass fraction) and an increase in coating thickness can improve the shielding rate of the composite materials to γ-rays. When the thickness of the coating is 1.6 mm and the content of Bi2O3 is 50%, the shielding rate of the composite to γ-rays (at 59.5 keV) reaches 46.1%. The shielding rate of the composite can be increased by adding appropriate metal additives, and the effect of adding Ta is better than that of Pb. The shielding rate of the composite to γ-rays (59.5 keV) can be increased from 28.4% to 31.5% by adding 5% Ta. An increase in Bi2O3 content (mass fraction) and an increase in the coating thickness can aggravate the agglomeration of functional particles in the material. The addition of metal additives can reduce agglomeration to a certain extent. Bi2O3 content, coating thickness, and metal additives all have an effect on the mechanical properties of the composite. If the coating is too thick or the functional particle content is too high, the tensile strength and elongation at break of the composite will be reduced.
Aiming at the difficulty of designing flexible shielding materials for lightweight and complex structures, the radiation shielding simulation model of coated fabric was established by SuperMC nuclear simulation software system and the γ-ray shielding performance of the material was predicted. Pb and Ta doped Bi/PU coated fabric composites were prepared by coating process. SEM, EDS, γ-ray shielding performance, mechanical properties, and wear resistance were tested. The results show that the simulated values of shielding performance are in good agreement with the measured values, the maximum deviation of the predicted value is 2.94% and the minimum is 0.25%. Doping Pb and Ta can increase the probability of the photoelectric effect and improve the γ-ray shielding performance of the material. When the doping amount of Ta is 5wt%, the shielding rate (simulation value) of Bi/Ta/PU coated fabric composites to 59.5 keV, 122 keV, and 184 keV γ-rays reaches 29.80%, 20.35%, and 8.09%, respectively, which is 3.13%, 2.32%, and 0.95% higher than that without doping. However, Ta is more environmentally safe and can replace Pb as a shielding additive. Doping auxiliary functional particles will improve the shielding performance but will reduce the material’s wear resistance and mechanical properties. After doping 5%Ta, the wear resistance index decreased by 6.81, and the tensile strength decreased by 4.5 MPa. The influence mechanism of process parameters on shielding performance is further revealed by visual analysis, which provides a new reference for the design of lead-free flexible shielding materials.
The radiation shielding simulation model of coated fabric (flexible composite) was established for the first time by SuperMC nuclear simulation software to help solve the problems of small volume, complex structure, and difficult design of flexible shielding materials, and the γ-ray shielding performance was calculated. Bismuth/polyurethane coated fabric was prepared by a coating method, and its scanning electron microscope, γ-ray shielding performance and mechanical properties were tested. The results show that the simulation accuracy was improved due to the one-to-one correspondence between the structural parameters and performance parameters of the simulation model and the actual samples. The simulation value was in good agreement with the measured value. The shielding performance and mechanical properties of fabric composites were improved after coating. Increasing the content of bismuth and coating thickness can improve the shielding performance of the coated fabric. However, when the content of bismuth was too large, or the coating was too thick, the mechanical properties were relatively decreased. The deposition of ray energy in the material was analyzed by the visual analysis method, and the influence mechanism of process parameters on shielding performance was further revealed, which provided a new theoretical reference for the design of flexible shielding materials. A shielding material design and performance prediction method based on SuperMC is proposed, which can be used for personalized customization design and performance prediction and evaluation before use. It has practical guiding significance for producing and manufacturing flexible fabric shielding materials for protective clothing and equipment.
With the rapid development of infrared detection and tracking technology, the combat concealment and viability of various military targets are seriously threatened, and the demand for military infrared camouflage is increasingly urgent. Individual combatants, as small moving targets, have the characteristics of small size, strong mobility, complex and changeable background, etc. Their infrared camouflage is more flexible and accurate than the equipment and engineering camouflage. The infrared camouflage textile material is soft and portable, which is the main embodiment of the infrared camouflage technology for individual soldiers. It can be used for infrared camouflage clothing, military tents, sleeping bags, and other equipment. Its research and development have been highly valued by many countries. In this article, details of the working principle, preparation methods, and recent research progress of flexible infrared camouflage textile materials are summarized. First of all, from the military application of infrared technology and the principle of infrared camouflage, the development status of infrared camouflage textile materials is summarized, and the research results of near-infrared and thermal infrared camouflage textile materials are introduced. Secondly, the camouflage conditions and research directions of new multi-band recombination and adaptive infrared camouflage textile materials are discussed. Finally, the challenges and opportunities of the future development of infrared camouflage textile materials, especially adaptive infrared camouflage textile materials, are considered.
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