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High-value utilization of CO_(2) to synthesize sulfur-doped carbon nanofibers with excellent capacitive performance

International Journal of Minerals,Metallurgy and materials 2020年第12期27卷 1666-1677页

作者： Meng-jun Hu Ming-zhu Yin Li-wen Hu Peng-jie Liu Shuo Wang Jian-bang Ge College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China Nuclear Engineering Program Department of Mechanical EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgVirginia 24061USA

Carbon nanofiber(CNF)is considered a promising material due to its excellent physical and chemical *** paper proposes a novel way to transform CO_(2) into heteroatom-doped CNFs,with the introduction of Fe,Co,and Ni as *** the electrolyte containing Ni O,Co2O3,and Fe_(2)O_(3) was employed,sulfur-doped CNFs in various diameters were *** the introduction of Fe catalyst,the obtained sulfur-doped CNFs showed the smallest and tightest diameter *** obtained sulfur-doped CNFs had high gravimetric capacitance(achieved by SDG-Fe)that could reach 348.5 F/g at 0.5 A/g,excellent cycling stability,and good rate *** comparison purposes,both Fe and nickel cathodes were tested,where the active metal atom at their surface could act as *** these two situations,sulfur-doped graphite sheet and sulfur-doped graphite quasi-sphere were the main products.

关键词： carbon dioxide capture electrochemical conversion carbon fiber molten salt

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In-Situ Crystal Growth of Iron-Copper MOF via Graphene Induction as an Electrode Material for the Asymmetric Supercapacitors

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Journal of Alloys and Compounds 2025年

作者： Sarah Hakeem Ayesha Siddique Rehan Ullah Saqib Ali Muhammad Talha Masood Zeeshan Ali Ghulam Ali Sofia Javed School of Chemical & Materials Engineering (SCME) National University of Sciences & Technology (NUST) H-12 sector Islamabad Pakistan School of Interdisciplinary Engineering & Science (SINES) National University of Sciences & Technology (NUST) H-12 sector Islamabad Pakistan School of Materials Science and Engineering Science Peking University Beijing 100871 China US. Pakistan Center for Advanced Studies in Energy (USPCASE) National University of Sciences & Technology (NUST) H-12 sector Islamabad Pakistan

Synthesizing crystalline MOFs embedded in conductive matrices like graphene, carbon nanotubes, and conductive polymers has been a subject of extensive research. Here, we present a facile hydrothermal approach for the crystallization of Fe-MOF materials, influenced by the addition of graphene nanosheets. Afterwards, conductive copper was introduced to synergistically interact with Fe-MOF to enhance its electrochemical properties. The samples’ crystallization was endorsed using various characterization techniques, including XRD, SEM, Raman, and FTIR. In addition, samples were tested in a tri-electrode system where the FeCu33-MOF/10 G sample displayed an exceptional specific capacitance of 1132 Fg -1 at 3 Ag -1 . Furthermore, the FeCu33-MOF/10 G || AC Asymmetric supercapacitor device was tested using a two-electrode system (with FeCu33-MOF/10 G and Activated Carbon (AC) as electrode materials). The ASC device displayed a remarkable specific capacitance of 309 Fg -1 with high energy density (E d ) and power density (P d ) of 51.07 Wh/kg and 8.5 kW/kg, respectively. The device also exhibited a cyclic stability of 96.06% and an excellent coulombic efficiency of 99.5% after 5000 cycles at 5 Ag -1 . Thus, the in-situ growth of Fe/Cu-MOFs on graphene enhances the charge-discharge stability and improves the energy and power density, validating this synthesis as a promising strategy for high-performance ASC devices.

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Polaron interfacial entropy as a route to high thermoelectric performance in DAE-doped PEDOT:PSS films

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National science Review 2024年第3期11卷 259-270页

作者： Jiajia Zhang Caichao Ye Genwang Wei Liang Guo Yuhang Cai Zhi Li Xinzhi Wu Fangyi Sun Qikai Li Yupeng Wang Huan Li Yuchen Li Shuaihua Wang Wei Xu Xuefeng Guo Wenqing Zhang Weishu Liu Department of Materials Science and Engineering Southern University of Science and Technology Academy for Advanced Interdisciplinary Studies and Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Department of Mechanical and Energy Engineering Southern University of Science and Technology Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences College of Chemistry and Molecular Engineering National Biomedical Imaging Centre Peking University Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology

Enhancing the thermoelectric transport properties of conductive polymer materials has been a long-term challenge, in spite of the success seen with molecular doping strategies. However, the strong coupling between the thermopower and the electrical conductivity limits thermoelectric performance. Here, we use polaron interfacial occupied entropy engineering to break through this intercoupling for a PEDOT:PSS(poly（3,4-ethylenedioxythiophene）-poly（4-styrenesulfonate）) thin film by using photochromic diarylethene（DAE） dopants coupled with UV-light modulation. With a 10-fold enhancement of the thermopower from 13.5 μV K-1to 135.4 μV K-1and almost unchanged electrical conductivity, the DAE-doped PEDOT:PSS thin film achieved an extremely high power factor of 521.28 μW m-1K-2from an original value of 6.78 μW m-1K-2. The thermopower was positively correlated with the UV-light intensity but decreased with increasing temperature, indicating resonant coupling between the planar closed DAE molecule and PEDOT. Both the experiments and theoretical calculations consistently confirmed the formation of an interface state due to this resonant coupling. Interfacial entropy engineering of polarons could play a critical role in enhancing the thermoelectric performance of the organic film.

关键词： thermoelectric PEDOT: PSS interfacial occupied entropy resonant coupling UV-light modulation

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EFFECT OF ALKALI HYDROXIDES ON THE STRENGTH AND FATIGUE OF FUSED-SILICA OPTICAL FIBER

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JOURNAL OF THE AMERICAN CERAMIC SOCIETY 1991年第10期74卷 2592-2598页

作者： MATTHEWSON, MJ RONDINELLA, VV LIN, BC KEYES, SW Fiber Optic Materials Research Program Department of Ceramic Science and Engineering Rutgers University Piscataway New Jersey 08855-0909

A two-point bend technique is used to determine the strength of "pristine" bare fused silica optical fiber in aqueous solutions of the group I alkali metal hydroxides (Li through Cs) in the concentration range 10(-4)N to 1N (pH range 10 to 14). In the highest concentration solutions, a strong cation effect is exhibited with a minimum strength for KOH while fibers in LiOH and CsOH are typically 20% and 10% stronger, respectively. The cation effect decreases with decreasing concentration until at 10(-4)N no effect is apparent. Tetramethylammonium hydroxide gives intermediate strengths between CsOH and LiOH. The results correlate closely with published results for the dissolution rate of silica which exhibit a maximum rate for KOH. In contrast, the results do not correlate with published subcritical crack growth data which show no cation effect for Na through Cs. These results support the pit etching model for pristine fiber strength proposed by Kurkjian et al. and argue against the presence of cracks or cracklike objects in these materials.

关键词： optical fibers strength fatigue alkalies hydroxides

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Effect of Mixing Strategy on the Structure-Properties of the PLA/PBAT Blends Incorporated with CNC

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Journal of Renewable materials 2022年第1期10卷 149-164页

作者： Deniz Sema Sarul Dogan Arslan Emre Vatansever Yusuf Kahraman Ali Durmus Reza Salehiyan Mohammadreza Nofar Polymer Science and Technology Program Institute of Science and TechnologyIstanbul Technical UniversityIstanbul34469Turkey Metallurgical&Materials Engineering Department Faculty of Chemical and Metallurgical EngineeringIstanbul Technical UniversityIstanbul34469Turkey Department of Chemical Engineering Faculty of EngineeringIstanbul University-CerrahpasaIstanbul34320Turkey Department of Materials Research and Technology Luxembourg Institute of Science and TechnologyEsch-sur-Alzette4362Luxembourg

Polylactide(PLA)/poly(butylene adipate-co-terephthalate)(PBAT)blend nanocomposites including 3 wt%of cel-lulose nanocrystals(CNCs)were prepared by melt compounding method in a twin-screw extruder and an inter-nal *** nanocomposites were formulated by diluting three different masterbatches prepared by solution casting method that contained 7 wt%of *** masterbatches were:(m1)PLA/PBAT/CNC masterbatch;(m2)PLA/CNC masterbatch;and(m3)PBAT/CNC *** were to explore how different prepara-tion methods affect the dispersion and localization of CNC and hence the properties of PLA/PBAT/CNC blend *** electron microscopy(SEM)was used to study the structural changes of the *** properties of PLA/PBAT blends and PLA/PBAT/CNC blend nanocomposites were also *** the samples prepared by internal mixer,the rheological behavior of blend nanocomposite prepared through premixing of CNC particles with PLA showed a transition from liquid-like to a gel-like *** to the rheological results and differential scanning calorimetry(DSC)analysis,it was found that the CNC overall enhanced the viscoelastic properties of blends and improved the PLA crystallization,*** mechanical analysis(DMA)illustrated that the incorporation of CNC also enhanced the elastic modulus of PLA/PBAT blends specifically above the glass transition temperature of *** expected improvements in mechanical properties did not occur due to the possible existence of residual solvent in the blends.

关键词： Polylactide poly(butylene adipate-co-terephthalate) cellulose nanocrystals blend nanocomposite morphology rheology

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A self-standing,UV-cured semi-interpenetrating polymer network reinforced composite gel electrolytes for dendrite-suppressing lithium ion batteries

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Journal of Materiomics 2019年第2期5卷 185-194页

作者： Ruiping Liu Zirui Wu Peng He Haoyu Fan Zeya Huang Lei Zhang Xinshuang Chang Hang Liu Chang-an Wang Yutao Li Department of Materials Science and Engineering China University of Mining&Technology(Beijing)Beijing 100083China School of Materials Science and Engineering State Key Laboratory of New Ceramics and Fine ProcessingTsinghua UniversityBeijing 100084China Department of Mechanical Engineering University of Alaska FairbanksFairbanksAK 99775United States Materials Science and Engineering Program and Texas Materials Institute The University of Texas at AustinTexas78712United States

A self-standing,flexible and lithium dendrite growth-suppressing composite gel polymer electrolyte membrane was designed for the use of room-temperature lithium ion *** multi-functional composite semi-interpenetrating polymer network(referred to as“Cs-IPN”)electrolyte membrane was fabricated by combining a UV-cured ethoxylated trimethylolpropane triacrylate(ETPTA)macromer with alumina nanoparticles in the presence of liquid electrolyte and thermoplastic linear poly(ethylene oxide)(PEO).The polymer electrolyte membrane exhibits a semi-interpenetrating polymer network structure and a higher room temperature ionic conductivity,which impart the electrolyte with a significant cycling(120 mAh g^(-1)after 200 cycles)and a remarkable rate(137 mAh g^(-1)at 0.1℃,130 mAh g^(-1)at 0.5℃,119 mAh g^(-1)at 1℃ and 100 mAh g^(-1)at 2℃)performance in Li/LiFePO4 *** importantly,the polymer electrolyte possesses superior ability to inhibit the growth of lithium dendrites,which makes it promising for next generation lithium ion batteries.

关键词： Gel polymer electrolytes Semi-interpenetrating polymer network UV-Cured reaction Ionic conductivity Lithium ion batteries

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Predicting the degradation behavior of magnesium alloys with a diffusion-based theoretical model and in vitro corrosion testing

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Journal of materials science & Technology 2019年第7期35卷 1393-1402页

作者： Zhenquan Shen Ming Zhao Dong Bian Danni Shen Xiaochen Zhou Jianing Liu Yang Liu Hui Guo Yufeng Zheng Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China 9955 Buffalo Speedway #4308 HoustonTXUSA Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China

Magnesium alloys have shown great potential for their use in the medical device field, due to the promising biodegradability. However, it remains a challenge to characterize the degradation behavior of the Mg alloys in a quantitative manner. As such, controlling the degradation rate of the Mg alloys as per our needs is still hard, which greatly limits the practical application of the Mg alloys as a degradable *** paper discussed a numerical model developed based on the diffusion theory, which can capture the experimental degradation behavior of the Mg alloys precisely. The numerical model is then implemented into a finite element scheme, where the model is calibrated with the data from our previous studies on the corrosion of the as-cast Mg-1 Ca and the as-rolled Mg-3 Ge binary alloys. The degradation behavior of a pin implant is predicted using the calibrated model to demonstrate the model’s capability. A standard flow is provided in a practical framework for obtaining the degradation behavior of any biomedical Mg alloys. This methodology was further verified via the comparison with enormous available experimental results. Lastly, the material parameters defined in this model were provided as a new kind of material property.

关键词： Degradation behavior Diffusion model Finite element simulation Magnesium alloy Corrosion Medical device

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POINT-DEFECT STRUCTURE OF GAMMA'-IRON NITRIDE AT 450-550-DEGREES-C

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REACTIVITY OF SOLIDS 1988年第2-3期5卷 177-190页

作者： CHEUNG, CT SIMKOVICH, G Metallurgy Program Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 U.S.A.

The composition of γ-iron nitride (“Fe 4 N”) was measured by a thermogravimetric method at 450–550°C at various nitrogen potentials. The composition (wt.-% of nitrogen) limits at 450, 500 and 550°C range from 5.82 to 5.90%, 5.78 to 5.90% and 5.71 to 5.89%, respectively. The results can be described satisfactorily by two thermodynamic relations: (i) a Langmuir-type isotherm that assumes all nitrogen atoms reside at regular, octahedral sites (1/2,1/2,1/2), and (ii) by considering “Fe 4 N” as a substantially ordered solution of nitrogen in iron with two types of minor disorder: (a) nitrogen vacancies at regular sublattice sites, and (b) interstitial nitrogen atoms which reside at the disordered sites of (1/2,0,0), (0,1/2,0) and (0,0,1/2). At a fixed temperature, it can be shown that the fraction of interstitial nitrogen increases with increasing nitrogen potential, whereas the fraction of nitrogen vacancies decreases with increasing nitrogen potentials. As the temperature is increased from 450 to 550°C, both types of defect increase with the fraction of interstitial nitrogen increasing from 0.21 to 0.35% at the γ/ϵ phase boundary, while the fraction of nitrogen vacancies increased from 1.42 to 3.47% at the α/γ phase boundary. From the nitrogen activity at α/γ equilibrium, the standard enthalpy and entropy of formation of “Fe 4 N” from α-iron and molecular nitrogen are found to be −9065.2 J mol −1 Fe 4 N (−2165.6 cal mol −1 Fe 4 N) and −47.5 J K −1 mol −1 Fe 4 N (−11.3 cal K −2 mol −1 Fe 4 N), respectively.

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An evaluation of the corrosion behavior of orthodontic Ni-Ti archwires as a function of residence time the oral cavity

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ECS Transactions 2012年第50期50卷 99-112页

作者： Britto, Káthia M.F. Macedo, Daniel A. Nascimento, Rubens M. Martinelli, Antonio E. Júnior, Hélio S. Materials Science and Engineering Post-Graduate Program Federal University of Rio Grande Do Norte 59072-970 Natal Brazil

The objective of the present study was to evaluate the effect of the residence time in the oral cavity on the electrochemical and microstructural properties of nickel-titanium superelastic and thermoelastic archwires aiming at establishing optimum treatment parameters regarding materials selection and maintenance of orthodontic apparatus. The corrosion behaviour of commercial archwires of different diameters was studied after periods of use from 1 to 3 months in the oral cavity of patients submitted to orthodontic treatment. Electrochemical measurements and scanning electron microscopy (SEM) were performed. The results revealed that the stiffness of superelastic archwires increased upon use, making it unnecessary to replace archwires in the early stages of treatment with the objective of adapting the diameter of the wire. Electrochemical tests suggested extremely high corrosion resistance of the nickel-titanium alloy even in severe acid environment. SEM images revealed limited pit formation concentrated in the archwire-bracket contacts. © The Electrochemical Society.

关键词： Dental orthoses

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Effect of surface oxidation on the interfacial and mechanical properties in graphite/epoxy composites composite bipolar plates

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Chinese Chemical Letters 2024年第11期35卷 539-542页

作者： Dongmei Yao Junsheng Zheng Liming Jin Xiaomin Meng Zize Zhan Runlin Fan Cong Feng Pingwen Ming Clean Energy Automotive Engineering Center and School of Automotive Studies Tongji UniversityShanghai 201804China College of Materials Science and Engineering Tongji UniversityShanghai 201804China

Epoxy resin-reinforced graphite composites have found extensive application as bipolar plates in fuel cells for stationary power supplies,valued for their lightweight nature and exceptional *** enhance the interfacial properties between graphite and epoxy resin(EP),surface oxidation of graphite was carried out using diverse functional *** assessments illustrated that the composites with graphite oxide resulted in heightened mechanical strength and toughness compared to pristine graphite,which could be attributed to the excellent interface ***,these composites displayed remarkable conductivity while simultaneously retaining their mechanical ***,molecular dynamics simulations outcomes unveiled that the inclusion of oxygen-containing functional groups on the graphite surface augmented the interfacial energy with EP,and the interface morphology between graphite and resin exhibited heightened stability throughout the stretching *** simple and effective technique presents opportunities for improving composites interfaces,enabling high load transfer efficiency,and opens up a potential path for developing strong and tough composite bipolar plates for fuel cells.

关键词： G/EP interface strength and toughness Epoxy resin-reinforced graphite composites Composite bipolar plates Molecular dynamics simulations Surface oxidation of graphite

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