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871.
Zemin He Ping Yu Haiyang Wang Jianjing Gao Yang Zhao Haiquan Zhang Yuzhen Zhao Zongcheng Miao 《Journal of the American Ceramic Society》2021,104(9):4389-4397
Ferroelectric BaTiO3 was combined with Ag nanoparticles for piezocatalytic and photocatalytic viewpoints. Microstructural characterization (X-ray diffraction and electron microscopy images) revealed that the Ag was successfully bounded with BaTiO3. X-ray photoelectron spectrum also confirmed the presence of Ag. Further, its performance was examined for dye degradation under visible light (for photocatalysis) and ultrasonication (for piezocatalysis). In both the catalysis processes, there was a significant improvement in Ag-loaded BaTiO3 sample-based catalytic reactions. Catalytic performance was evaluated for multiple cycles and was found consistent. Scavenger tests were also performed to understand catalytic reactions. 相似文献
872.
Rui Xu Jing Song Shijiao Zhao Lei Nie Changsheng Deng Shaochang Hao Xingyu Zhao Bing Liu Jingtao Ma 《Journal of the American Ceramic Society》2021,104(11):5489-5500
ZrO2 microspheres are widely used as a simulant of UO2 in the development of nuclear fuel. However, the cracking of ZrO2 microspheres prepared by internal gelation is still a challenge during drying and sintering processes. To address this issue, we designed and optimized the washing process for obtaining crack-free ZrO2 microspheres. Through thermogravimetric, infrared, Raman, BET, and SEM analysis, it is shown that the cracking of the microspheres is mainly related to the pores in microspheres. The washing solvent with low surface tension is used to reduce the effect of capillary force on pore shrinkage. Therefore, the optimal washing process was designed as trichloroethylene (TCE)—0.5 M NH3.H2O—Propylene glycol methyl ether (PM) and gel microspheres with a high specific surface area of 315.3 m2/g and pore volume of 0.4125 cm3/g were obtained. The characterizations also further showed that when the microspheres were dried and sintered, the water vapor and the decomposition gas of organic matter were completely released from the pores in the microspheres. Our new washing process could be directly extended for preparing crack-free ceramic microspheres by internal gelation. 相似文献
873.
Shuai Huang Lixin Yu Kangliang Peng Youjun Zhao Jindi Wang Mengmeng Shang 《Journal of the American Ceramic Society》2021,104(11):5848-5858
To enhance the display quality of light-emitting diodes (LEDs), it is of great significance to exploit green/yellow-emitting phosphors with narrow emission band, high quantum yield, and excellent color purity to satisfy the application. Herein, orthophosphate-based green/yellow-emitting Na3Tb(PO4)2:Ce3+/Eu2+ (NTPO:Ce3+/Eu2+) phosphors have been successfully synthesized by a facile solid-state reaction method. The absorption band of NTPO samples was extended to the near-ultraviolet region and the absorption efficiency was significantly improved owing to a highly efficient energy transfer from Ce3+/Eu2+ ion to Tb3+ ion in NTPO host certified by time-resolved PL spectra. Upon 300 nm excitation, the NTPO:Ce3+ is characterized by ultra-narrow-band green emission of Tb3+ with an absolute quantum yield of 94.5%. Unexpectedly, NTPO:Eu2+ emits bright yellow light with a color purity of 73% as a result of the blending of green light emission from Tb3+ and red light emission from Eu3+. The thermal stability has been improved by controlling the stoichiometric ratio of Na+. The prototype white LED used yellow-emitting NTPO:Eu2+ phosphor has higher color-rendering index (Ra = 83.5), lower correlated color temperature (CCT = 5206 K), and closer CIE color coordinates (0.338, 0.3187) to the standard white point at (0.333, 0.333) than that used green-emitting NTPO:Ce3+ phosphor, indicating the addition of the yellow light component improved the Ra of the trichromatic (RGB) materials. 相似文献
874.
Tiesong Xu Minghui Zhong Xiaolin Liang Jia Liu Bin Yan Jing Xiao Kai Jiao Xiange Wang Nian Si Zhongda Pan Zheming Zhao Xunsi Wang Peiqing Zhang Qiuhua Nie Shengchuang Bai Rongping Wang Junjie Zhang 《Journal of the American Ceramic Society》2021,104(11):5671-5678
Extinction ratio (ER) is one of the important parameters to characterize the polarization-maintaining (PM) performance of the fiber. In this paper, we report the preparation and properties of a novel chalcogenide microstructure fiber with a high ER. We fabricate a preform using a peeled-off extrusion method. The core and cladding material of the fiber are Ge9As23Se68 and Ge10As22Se68. The preform was drawn into a fiber with an average ER of −17.08 dB. The loss of the fiber is less than 2 dB over 5.20–8.55 μm, and the minimum loss of the fiber is 0.57 dB/m at 6.2 μm. Moreover, a flat mid-infrared supercontinuum spectrum spanning from 1.53 to 12.50 μm is generated by pumping an 18-cm-long PM fiber for the first time. 相似文献
875.
Hu Chuang Zang Guo-Long Luo Jun-Tao Liu Qi Zhao Quan 《Journal of Applied Electrochemistry》2021,51(6):847-859
Journal of Applied Electrochemistry - The electrocatalytic reduction of CO2 is a promising research direction in resource utilization and sustainable energy development. However, there is still a... 相似文献
876.
In this paper, Si/carbon nanotubes@melamine-formaldehyde resin (MFR)-based carbon (Si/CNTs@C) composites have been fabricated by surface modification, electrostatic self-assembly, cross-linking of MFR under hydrothermal treatment and further carbonization. The microstructure of the Si/CNTs@C composites was characterized, and the effects of CNTs content in Si/CNTs@C composites on their electrochemical performances were also investigated in detail. The results indicate Si/CNTs@C composites as anode materials of Li-ion batteries exhibit better high-rate and cycling performances compared to Si and Si@MFR-based carbon composites. Notably, Si/CNTs@C composites with 10.4 wt% CNTs show specific capacities of 1900, 1879, 1,688, 1,394, 1,189 mAh·g−1 at 0.2, 0.5, 1, 2, and 3 A·g−1, respectively. Even at 4 and 5 A·g−1, their capacities still reach 970 and 752 mAh·g−1, respectively. Moreover, they deliver a reversible capacity of 1,184 mAh·g−1 at 0.5 A·g−1 after 100 cycles. Therefore, the reasonable structure is of great significance for enhancing the electrochemical performances of Si-based composites. 相似文献
877.
Qianyu Yang Chen Gao Xuemei Zhang Xingyu Zhao Yiqing Fu Chihui Tsou Chunyan Zeng Li Yuan Zejun Pu Yiqing Xia Yuping Sheng Yu Fang 《应用聚合物科学杂志》2021,138(13):50308
Shape memory hydrogels (SMHs) can fix the hydrogels in a provisional shape and restore the initial shape under external stimulation. Herein, a dual-responsive shape memory hydrogel with dual-responsive swelling and self-healing properties is presented in this work. The SMHs were fabricated by one-step emulsion copolymerization of acrylic acid (AAc), acrylamide (AAm) and stearyl methacrylate (SMA). Sodium alginate (SA) was introduced as an interpenetrating polymer in the network. With ionic cross-linking between -COO− and Fe3+ or saline-reinforced hydrophobic association, the hydrogels can be fixed in a provisional shape, which can be restored by immersing the hydrogels in vitamin C solution or pure water, respectively. When the as-prepared hydrogels were immersed in FeCl3 solutions, additional ionic cross-linking between Fe3+ and -COO− could be formed, thus constructing the dual physically cross-linked (DPC) network, which endows the hydrogels with excellent fracture stress (2.6 MPa) and toughness (5.47 MJ/m3). Besides, the reversible physical cross-linkings endowed the hydrogel with outstanding self-healing capability. Furthermore, the pH and saline responsive swelling properties of the SMHs are additional fantastic properties. Therefore, we believe that this simple strategy provides a great opportunity for the preparation of SMHs with multiple intellectual performances. 相似文献
878.
Marine biofouling had been a headache when engaging in marine activities. The most effective and convenient method for dealing with this problem was to apply antifouling coatings. But now a single anti-fouling system was hard to satisfy the requirement of anti-fouling simultaneously. Therefore, it was particularly important to develop novel multi-system anti-fouling technology. In the work, a novel polymer coatings with polydimethylsiloxane (PDMS) segments in the main chain and hydrolysable side chain was designed and synthesized which showed low surface energy and self-polishing performance, and then we creatively covalently immobilized the polyurethane on the surface of multi-carbon nanotubes (MWNTs) to form multisystem antifouling coating. The results showed that the polymer coating would produce hydrolysable regions in the hydrophobic PDMS segment to endure the polymer coating hydrophobic and hydrolysis properties when contacted with water. In addition, the self-polishing rate and the surface energy could be regulated by varying its copolymerization, and the addition of MWNTs could kill the microorganisms and endowed the polymer coating itself enhanced antibacterial effect. Furthermore, considering the high specific surface area and physicochemical characteristics of MWNTs, it could be combined with antifoulant Cu2O through a polar or non-polar combination as a carrier to control the release rate of Cu2O in coatings. 相似文献
879.
Hybrid anion exchange membranes (AEMs) were prepared via chemically functionalizing and crosslinking poly(styrene-b-[ethylene-co-butylene]-b-styrene) (SEBS) copolymers and low molecular weight homo-polystyrene (hPS). Via sequential chloromethylation, crosslinking, quaternization, and alkalization, a series of hPS/SEBS AEMs were obtained with varying content of hPS. Systematic structural, morphological, mechanical, absorption, and transport measurements reveal that these properties depend on the total PS content in the membranes. Particularly, increasing total PS content causes (a) PS domains in the AEMs transition the cylindrical morphology to lamella-like morphology with comparable correlation length; (b) Young's modulus, water uptake, swelling ratio, ionic exchange capacity and ionic conductivity of the AEMs, and Tg of PS phase increase. In addition, the alkaline stability of the hPS/SEBS AEMs is also improved by addition of hPS. These findings suggest that the proposed method can develop high performance SEBS AEMs that are suitable for fuel cell applications. 相似文献
880.
Jianping Shi Wei Zeng Zhiwang Yang Ju Li Pufang Zhao Hongtao Li Xingxing Yan Na Wen Ziqiang Lei Denglong Chen Jie Guan 《应用聚合物科学杂志》2021,138(21):50500
Organic–inorganic hybrid flame retardant was obtained by modifying aluminum hydroxide with different particle size with 1-hydroxyethylidene-1,1-diphosphonic acid. The structure of the organic–inorganic hybrid flame retardant is characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy, while 1H-NMR spectroscopy only characterizes specific samples. The thermal stability and flame retardancy of the samples were analyzed by thermogravimetric analysis, limiting oxygen index (LOI), vertical combustion of UL-94 and cone calorimeter. The results show that the modified 10 μm aluminum hydroxide has a better effect than the 25 μm aluminum hydroxide and 100 nm aluminum hydroxide. Compared with pure polyethylene terephthalate (PET), the LOI value of the best sample is increased by 24.4%, and UL-94 V reaches V-0 level. Heat release rate, total heat release rate, and carbon monoxide production rate decreased by 45.8%, 33.2%, and 41.5%, respectively, compared to pure PET. The results showed that the aluminum hydroxide with a particle size of 10 μm exhibited the best flame retardant effect, which could be attributed to the decomposition of organic phosphoric acid and the dehydration of aluminum hydroxide, yielding a higher amount of residual carbon. 相似文献