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Synthesis of(HfZrTiNbTa)N powders via nitride thermal reduction with soft mechano-chemical assistance

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Journal of Advanced Ceramics 2023年第3期12卷 565-577页

作者： Xiang Liu Youjun Lu Qian Xu Lutong Yang Hongfang Shen Wenzhou Sun Xiao Zhang Yanmin Wang School of Materials Science&Engineering North Minzu UniversityYinchuan 750021China College of Materials Science&Engineering South China University of TechnologyGuangzhou 510641China

High-entropy nitride powders are one of prerequisite materials for the preparation of high-performance high-entropy nitride *** this paper,high-entropy(HfZrTiNbTa)N powders were synthesized via nitride(i.e.,silicon nitride(Si_(3)N_(4)))thermal reduction with soft mechanochemical *** results show that metal oxides like hafnium dioxide(HfO_(2)),zirconium dioxide(ZrO_(2)),titanium dioxide(TiO_(2)),niobium pentoxide(Nb_(2)O_(5)),and tantalum pentoxide(Ta_(2)O_(5))can all be transformed into the corresponding metal nitrides in the presence of Si_(3)N_(4)at 1700℃,and solid solution of the metal nitrides can be formed as the temperature increases to 2100℃.The high-entropy(HfZrTiNbTa)N powders with submicron-sized particles,a narrower size distribution,and a single face-centered cubic(fcc)structure are obtained from raw material mixtures ground for 10 h and subsequently sintered at 1800℃.In addition,the high-entropy bulk nitride ceramics with relative density(Rw)of 94.31%±0.76%,Vickers hardness of 21.00±0.94 GPa,and fracture toughness(KIC)of 3.18±0.16 MPa·m1/2 are obtained with submicron-sized powders,which are superior to those obtained with micron-sized powders.

关键词： soft mechanochemistry thermal reduction high-entropy nitride powders high-entropy nitrideceramics

Metal Fe,Ni and Fe-Ni Fine Fibers Derived from the Organic Gel-thermal reduction Process

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Journal of Wuhan University of Technology(Materials Science) 2007年第4期22卷 577-581页

作者：沈湘黔 School of Material-Science and Engineering Jiangsu University

The organic gel-thermal reduction process was successfully used for the preparation of magnetic metal Ni, Fe, Fe-Ni fine fibers from raw materials of citric acid or lactic acid and metal salts. Ni, Fe and Fe-Ni fine fibers synthesized were featured with diameters of around 1 μm and lengths of as long as 2 m for Ni fibers, 0.5 m for iron fibers, 1 m for Fe-Ni fibers. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of these gel precursors were characterized by FTIR, XRD,TG/DSC and SEM, respectively. The gel spinnability largely depends on molecular structures of metal-carboxylate complexes formed in the gel. It is reasoned that these gels consist of linear-type structural molecules [（C6H6O7）Ni]n or [（C6H5O7）2Ni3] for the nickel citrate gel, [（C3H5O3）3Fe] for the ferric lactate gel, [（C6H5O7）5（NiFe）3] for the iron-nickel citrate gel respectively and the gels obtain showed a good spinning performance.

关键词： magnetic metal fiber organic-gel thermal reduction spinning performance

Preparation of ferromagnetic metal fine fibers by organic gel-thermal reduction process

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Journal of Central South University of Technology 2007年第5期14卷 607-611页

作者：曹凯沈湘黔景茂祥周建新 School of Materials Science and Engineering Jiangsu University

The organic gel-thermal reduction process was used for the preparation of ferromagnetic metal Ni, Co and Fe fine fibers from the raw materials of citric acid, lactic acid and metal salts. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of these gel precursors were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermo-gravimetric/differential scanning calorimetry and scanning electron microscopy. The results show that spinnability of gel largely depends on molecular structure of metal-carboxylate complex that is a linear-type structure formed in the gel. As a result, the gels exhibit a good spinnability. Metal Ni, Co and Fe fine fibers are featured with diameters of around 1 μm and a high aspect ratio up to 1×106.

关键词： ferromagnetic metal fiber organic gel thermal reduction spinnability

Preparation and electromagnetic shielding properties of PET/rGO/SWCNT composite fabric

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合成纤维工业 2024年第5期47卷 58-62,68页

作者： ZHANG Xu LIU Xuejiao YAN Yehai School of Polymer Science and Engineering Qingdao University of Science and TechnologyQingdao 266042

Graphene oxide(GO)with excellent dispersion ability can assist the dispersion of single-walled carbon nanotube(SWCNT)and promote the formation of uniform and stable GO/SWCNT coating *** highly conductive polyethylene terephthalate/reduced graphene oxide/SWCNT(PET/rGO/SWCNT)electromagnetic shielding composite fabric was successfully prepared by anchoring rGO/SWCNT on PET fabric via dip-coating piror to low-temperature thermal *** results showed that the carboxyl groups and hydroxyl groups formed of hydrophilic-treated PET were conducive to the formation of hydrogen bonds with that of GO,which enhanced the interaction between PET fabric and GO/SWCNT coating;the loading of GO/SWCNT increased with the number of dip-coating,the unit area loading of rGO/SWCNT in the final composite fabric was 2.7 mg/cm^(2) after 10 dip-coating cycles and thermal reduction;the PET/rGO/SWCNT composite fabric had a continuous and dense conductive network,with a conductivity of up to 41.6 S/m and the average electromagnetic interference shielding effectiveness in X-band was 22 dB;the flexible PET/rGO/SWCNT composite fabric was not only easy to process,but also exhibited excellent conductivity and shielding efficiency,showing great potential in the application of electromagnetic shielding fabrics.

关键词： electromagnetic interference shielding graphene oxide single-walled carbon nanotubes conductive fabric thermal reduction

Theoretical energy consumption analytical method for metal separation process

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Journal of thermal Science 2010年第4期19卷 377-382页

作者： Dehong XIA,Yingchun SHANG,Ling REN and Yifan LI Department of thermal Engineering,University of Science and Technology Beijing,Beijing 100083 Department of thermal Engineering University of Science and Technology Beijing Beijing China

The theoretical energy consumption(TEC)analytical methods and the calculated models for the electrolytic and thermal reduction metal separation processes have been put forward based on thermodynamics and physical chemistry principles,providing theoretical foundation for choosing the optimum metal separation *** on the models,the TECs of the Mg separation processes are taken as an example,and have been calculated and analyzed contrastively,including the MgCl_2 electrolytic method,the MgO electrolytic method with inert electrode and with carbon anode,and the silicothermic *** is shown that the thermal method is more reasonable than the electrolytic methods to separate Mg under low efficiency of coal power generation.

关键词： metal separation theoretical energy consumption electrolysis thermal reduction

Highly Sensitive and Portable Gas Sensing System Based on Reduced Graphene Oxide

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Tsinghua Science and Technology 2016年第4期21卷 435-441页

作者： Wentian Mi Shih-Wen Chiu Tao Xue Yuanquan Chen Hanyu Qi Yi Yang Kea-Tiong Tang Tian-Ling Ren Institute of Microelectronics&Tsinghua National Laboratory for Information Science and Technology(TNList) Tsinghua University Department of Electrical Engineering Tsing Hua University

Graphene has been widely used in gas-sensing applications due to its large specific surface area and strong adsorption ability. Among different forms of graphene used as gas-sensing materials, reduced graphene oxide is one of the most convenient and economical materials to integrate with Si-based electronics, which is very important to graphene-based gas sensors. In addition, the stacking structure of graphene oxide flakes facilitates absorption and detection of gas molecules. Based on reduced graphene oxide, a highly sensitive and portable gas-sensing system was demonstrated here. Solution-based graphene oxide was cast on a chip like a TF memory card and then reduced thermally. A signal acquisition system was designed to monitor resistance variation as a sign of gas concentration. This miniature graphene-based gas sensor array demonstrates a new path for the use of graphene in gas-detection technologies. And the creation of a sensitive and portable graphene gas sensor also shows great potential in fields such as medicine and environmental science.

关键词： reduced graphene oxide gas sensor signal acquisition system thermal reduction

Temperature-induced resistance transition behaviors of melamine sponge composites wrapped with different graphene oxide derivatives

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Journal of Materials Science & Technology 2021年第26期85卷 194-204页

作者： Cheng-Fei Cao Wen-Jun Liu Hui Xu Ke-Xin Yu Li-Xiu Gong Bi-Fan Guo Yu-Tong Li Xiao-Lan Feng Ling-Yu Lv Hong-Tao Pan Li Zhao Jia-Yun Li Jie-Feng Gao Guo-Dong Zhang Long-Cheng Tang Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education College of MaterialChemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Temperature-re s ponsive resistance transition behaviors of the melamine sponges wrapped with different graphene oxide derivatives(***,wide-ribbon and sheet)were *** sponge composites coated by three types of GO derivatives were prepared by a simple dip-coating *** these composites show good mechanical flexibility and reliability(almost unchanged compressive stress at 70%strain after 100 cycles),high hydrophobicity(water contact angle>120°),excellent flame resistance(self-extinguishing)and structural stability even after burning,which was used to construct the resistance-based fire alarm/warning ***,the different resistance response behaviors of such sensors are strongly dependent on the GO size and network formed on the MF skeleton ***,at a fixed high temperature of~350℃,the three fire alarm sensors show different response time(to trigger the alarm light)of 6.3,8.4 and 11.1 s for nanoribbon,wide-ribbon and sheet at the same concentration,*** structural observation and chemical analysis demonstrated that the discrepancy of temperature-responsive resistance transition behaviors of various GO derivatives was strongly determined by their different thermal reduction degrees during the high-tempe rature or flame treating *** work offers a design and development for construction of smart fire alarm device for potential fire prevention and safety applications.

关键词： Graphene oxide derivatives Fire warning response Structure and morphology thermal reduction Temperature-responsive resistance transition

Enhancement in boiling heat transfer performance using reduced graphene oxide coating with controllable components and porous structures

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Science China(Technological Sciences) 2023年第7期66卷 2080-2092页

作者： XU ZhiMing WANG XiaoLiang JIANG HongPeng ZHANG ZhiRong SHAN DeBin GUO Bin QIU YunFeng XU Jie Key Laboratory of Micro-Systems and Micro-Structures Manufacturing of Ministry of Education Harbin Institute of TechnologyHarbin 150080China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Medicine and Health Harbin Institute of TechnologyHarbin 150080China School of Chemistry and Chemical Engineering Yancheng Institute of TechnologyYancheng 224051China

Enhancement in boiling heat transfer performance is significant for addressing thermal management bottlenecks of advanced electronic *** graphene oxides(rGO)are regarded as promising candidates for thermal management due to their excellent thermal properties,chemical stability and adjustable *** this study,rGO coatings with micron pores and controllable oxygen contents are prepared on Al substrate via cathodic electrophoretic deposition and subsequent thermal annealing,leading to enhanced pool boiling *** heat transfer coefficient for Al/rGO450is 37.2 kW m-2K-1,which is increased by 112.6%compared with bare Al,also outperformed previously reported Al based *** is assumed that the hydrophilic and aerophobic r GO coatings effectively promote the liquid infiltration and bubble departure during pool boiling ***,repeatability tests indicate the durable stability of vertically oriented rGO *** nonequilibrium molecular dynamics simulation indicates that the interfacial transmission coefficients of Al/rGO increase after thermal annealing,indicative of the enhanced heat transfer performance of heterogeneous *** study opens a new avenue for endowing metal substrates with high pool boiling performance using porous carbon coating nanoengineering strategy with controllable morphology and components.

关键词： graphene cathodic electrophoretic deposition boiling heat transfer thermal reduction interfacial nanoengineering

Langmuir-Blodgett assembly of ultra-large graphene oxide films for transparent electrodes

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Transactions of Nonferrous Metals Society of China 2012年第10期22卷 2504-2511页

作者：郑庆彬师丽芳杨俊和上海理工大学材料科学与工程学院上海200093 香港科技大学机械工程系

Monolayer ultra-large graphene oxide （UL-GO） sheets with diameter up to about 100 μm were synthesized based on a chemical method. Transparent conductive films were produced using the UL-GO sheets that were deposited layer-by-layer on a substrate by the Langmuir-Blodgett （L-B） assembly technique. The films produced from UL-GO sheets with a close-packed flat structure exhibit exceptionally high electrical conductivity and transparency after thermal reduction. A remarkable sheet resistance of 605 -/sq at 86% transparency is obtained, which outperforms the graphene films grown on a Ni substrate by chemical vapor deposition. The technique used to produce transparent conductive films is facile, inexpensive and tunable for mass production.

关键词： graphene oxide Langmuir-Blodgett assembly transparent electrode thermal reduction