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Photoreactive polymer and c,H-insertion reaction to tailor the properties of cHA/gelatin-based scaffold

INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND cHARAcTERIZATION 2022年第5期27卷 326-345页

作者： Ardhani, Retno Suraya, Tiyastiti Wulanjati, Martha Purnami Ana, Ika Dewi Ruehe, Jurgen Pidhatika, Bidhari Univ Gadjah Mada Fac Dent Dept Dent Biomed Sci Yogyakarta Indonesia Minist Ind Ctr Standardizat & Ind Serv Leather Rubber & Plas Jl Sokonandi 9 Yogyakarta Indonesia Natl Res & Innovat Agcy Republ Indonesia PRTPP BR Res Ctr Food Technol & Proc Yogyakarta Indonesia Univ Freiburg Freiburg Inst Interact Mat & Bioinspired Technol Dept Microsyst Engn IMTEK DFG Cluster Excellence LivMatS Freiburg Germany Natl Res & Innovat Agcy Republ Indonesia BRIN Jakarta Indonesia

A series of photoreactive polymers containing poly(N,N-dimethylacrylamide) and 2-hydroxy-(4-methacryloyloxybenzophenone), P(DMAA-n%MABP-OH), was explored to modify sheet-formed carbonated hydroxyapatite/gelatin (cHA/gelatin) scaffold. Under UV-light illumination, the benzophenones react with any c-H bonds in their vicinity through a c,H-insertion mechanism, enabling PDMAA-based hydrogel formation that is covalently attached to the gelatin. NMR spectroscopy confirmed the chemical structure of P(DMAA-n%MABP-OH) polymers with aimed n = 1, 5, 10, while GPc determined their molecular masses. The benzophenone reactivity under UV-light illumination for 0-240 min. was demonstrated using UV-Vis spectroscopy at 240-400 nm. After immobilization of P(DMAA-n%MABP-OH) onto the cHA/gelatin scaffold, typical FTIR vibration bands of both compounds could be detected on the spectra of the modified scaffolds. SEM images showed that the scaffold is highly porous with approximately 100 mu m thickness. P(DMAA-n%MABP-OH) addition led to 2-3 times increase in thickness and 15-19% mass addition. Furthermore, it was shown that chemical (degradation and ca2+ release profile), physical (4-7 swelling index), mechanical (0.06-0.17 MPa wet tensile strength and 0.2-0.8 MPa elastic modulus), and biological (cell adhesion) properties of the scaffold could be tailored by varying the photocrosslinker content. cytotoxicity test showed that all studied cHA/gelatin-based scaffolds were nontoxic (>80% cell viability).

关键词： c H-insertion crosslinking hydrogel photoreactive polymer scaffold

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Effect of off-axis angle on mesoscale deformation and failure behavior of plain-woven c/Sic composites with digital image correlation

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JOURNAL OF THE EUROPEAN cERAMIc SOcIETY 2022年第12期42卷 4712-4722页

作者： Teng, Xuefeng Lyu, Shuangqi Hu, Xiaoan Jiang, Yun Nie, Xiangfan Liu, Xin Li, Longbiao Nanchang Hangkong Univ Sch Aircraft Engn Nanchang 330063 Peoples R China Jiangxi Key Lab Micro Aeroengine Nanchang 330063 Peoples R China Civil Aviat Flight Univ China Aviat Engn Coll Guanghan 618307 Sichuan Peoples R China Nanchang Hangkong Univ Anal & Testing Ctr Nanchang 330063 Peoples R China AF Engn Univ Sci & Technol Plasma Dynam Lab Xi'an 710038 Shaanxi Peoples R China China Acad Launch Vehicle Technol Beijing 100076 Peoples R China Nanjing Univ Aeronaut & Astronaut Coll Civil Aviat Nanjing 210016 Peoples R China

In this study, the deformation response and failure behavior of a plain-woven c/Sic composite were investigated under on-axis and off-axis tensile loading. Digital image correlation (DIc) was utilized to characterize the full field deformation and mesoscale strain distribution. The test results indicate a strong influence of the woven architecture on the mechanical properties and strain distribution, and the materials exhibit failure modes dependent on the loading directions or off-axis angles: the fracture positions of different layers are the same under off-axial load, while for on-axil loading, the fracture positions of different layers do not affect each other. SEM results provide direct evidence that the width of the off-axis specimen has a great influence on the mechanical properties. The reduction of the modulus and strength of off-axis specimen, is not only due to the off axis loading, but also due to the reduction of effective bearing area or effective bearing fiber.

关键词： Plain-woven c Sic composites Digital image correlation Off-axis Failure behavior

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Regenerated LiFePO4/c for scrapped lithium iron phosphate powder batteries by pre-oxidation and reduction method

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IONIcS 2022年第5期28卷 2125-2133页

作者： Zhang, Hao Wang, Lihua chen, Yongzhi Wen, Xu Changsha Univ Coll Mech & Elect Engn Changsha 410022 Peoples R China Hunan Inst Sci & Technol Coll Mech Engn Yueyang 414006 Peoples R China

The cathode materials of scrapped lithium-iron phosphate battery are mainly composed of LiFePO4/c, conductive agent and PVDF, etc. Unreasonable disposal will cause serious environmental pollution and waste of scarce resources. In this paper, cathode materials were regenerated by pre-oxidation and reduction method. Impurities such as carbon coating, conductive agent, and PVDF were removed and LiFePO4/c was converted to Fe2O3 and Li3Fe2(PO4)(3) by pre-oxidation. After the addition of sucrose, regeneratedLiFePO(4)/c was synthesized under reduction process. The effects of calcination temperature and sucrose addition on the microstructure and electrochemical properties of regenerated LiFePO4/c were studied. The regenerated LiFePO4/c had excellent cycling stability when the sucrose addition was 12% and calcined at 700 celcius. The initial discharge specific capacity of regenerated LiFePO4/c was 145.51 mAh g(-1) at 0.5 c. After 200 cycles, the discharge specific capacity was 145.25 mAh g(-1) (capacity retention rate: 99.82%). It provides a new inspiration for the high-value recycling and regeneration of the other scrapped lithium-ion batteries.

关键词： Scrapped lithium-ion batteries Regenerated LiFePO4 c Pre-oxidation and reduction

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Role of fiber-matrix adhesion at cFRP stage on microstructure and mechanical properties of c/c-Sic composite

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INTERNATIONAL JOURNAL OF APPLIED cERAMIc TEcHNOLOGY 2022年第1期19卷 79-90页

作者： Dai, Jixiang Zhang, Zhaofu Zu, Yufei Sha, Jianjun Dalian Univ Technol State Key Lab Struct Analyses Ind Equipment Dalian 116024 Peoples R China Dalian Univ Technol Key Lab Adv Technol Aerosp Vehicles Dalian Peoples R China Xian Aerosp Composites Res Inst Xian Peoples R China

In order to understand the role of fiber-matrix adhesion (FMA) at carbon fiber-reinforced polymer (cFRP) stage on the microstructure and mechanical properties of c/c-Sic composite via liquid silicon infiltration (LSI) process, the FMA was adjusted by thermal treatment of carbon fibers at different temperatures and evaluated by means of single fiber push-out technique. The microstructure was characterized by optical microscopy and scanning electron microscopy. The mechanical properties were measured by the double-notched shear test, three-point flexural test, and single edge-notched beam test, respectively. Results indicated that the microstructure and mechanical properties of c/c-Sic composite via LSI were closely associated with the FMA at cFRP stage. The microstructure of c/c-Sic composite fabricated by using the cFRP with high FMA presented nonhomogeneous distribution and concentration of Sic matrix. In contrast, the c/c-Sic composite fabricated by using the cFRP with low FMA, the high content of Sic distributed homogeneously and surrounded the fiber, which resulted in a strong bonded c-Sic interface. The strong c-Sic interface is detrimental to the fracture toughness, but it is beneficial to the improvement of oxidation resistance. To obtain desired mechanical properties of c/c-Sic composite, the control of interface bonding is important, which can be realized by modifying the FMA at cFRP stage.

关键词： carbon fiber c c-Sic composite ceramic matrix composites fiber-matrix bonding microstructure control

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Effect of rotary ultrasonic machining on surface structure and ablation resistance of c/c composite

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cERAMIcS INTERNATIONAL 2022年第13期48卷 18246-18256页

作者： Shu, Jing Liao, Wenhe Zheng, Kan Abd Elbadia, Tarek Nanjing Univ Sci & Technol Sch Mech Engn Nanjing Jiangsu Peoples R China Mil Tech Coll Mech Design & Prod Dept Cairo Egypt

c/c composite is widely used in aerospace due to excellent high temperature mechanical properties. Improving its ablation resistance has become the focus of attention. Due to anisotropy of composite materials, the difference of thermal conductivity and thermal expansion coefficient between fiber and matrix, surface morphologies affect ablation performance greatly. In particular, fiber exposed length (FEL) and crack had a significant impact on its ablation resistance. Therefore, this paper constructed a FEL theoretical model based on machining damage, and verified that the error of the modified model was within 12 % through experiments. Meanwhile, improvement effect of rotary ultrasonic machining (RUM) was clarified. It is found that RUM reduced FEL by 15%~38% in all fiber angles and decreased the crack pores on machined surface. Then, oxyacetylene ablation experiments on c/c composite surface under conventional machining (cM) and RUM were carried out. The results showed that RUM surface had better ablation resistance, and interface ablation and porosity decreased significantly.

关键词： c c composite RUM Morphology Oxyacetylene ablation

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Ti-Fe-Si/c composites as anode materials for high energy li-ion batteries

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ENERGY SOURcES PART A-REcOVERY UTILIZATION AND ENVIRONMENTAL EFFEcTS 2022年第2期44卷 5154-5171页

作者： Nuhu, Bage Alhamdu Adun, Humphrey Bamisile, Olusola Mukhtar, Mustapha Southwest Petr Univ Sch Chem & Chem Engn Chengdu Peoples R China Cyprus Int Univ Energy Syst Engn Dept Mersin 10 Nicosia Turkey Chengdu Univ Technol Coll Nucl Technol & Automat Engn Chengdu Sichuan Peoples R China Guangdong Univ Petrochem Technol Sch Econ & Management Maoming Chinese Provinc Peoples R China

In this study, Ti-Fe-Si composites were prepared by one step ball-milling method as anode materials for Li-ion batteries. The effects of ball-milling speed and time were studied by X-ray diffraction, electron microscopy, and Fe-57 Mossbauer spectroscopy. changes in the composition and microstructure of the composites were observed and related to the electrochemical performance. Increasing ball-milling speed led to the formation of FeSix alloys that reduced the specific capacity while increasing the ball-milling time improved the particle size morphology and homogeneity. Discharge/charge profiles for the first two cycles were carried out at 0.05c current rate (1c = 1260 mAh.g(-1)for Li3.75Si). The first discharge for Ti-Fe-Si showed a LixSi reaction plateau of 1100 mAh.g(-1), which were reversible and yielded columbic efficiency (cE) 77% and 90% in the first and second cycles, respectively. This capacity plateau indicated the insertion of about 3.25 Li into silicon. For the composite containing an additional 10% carbon SP, the theoretical capacity was about 1130 mAh.g(-1), the discharge curve showed that the first discharge plateau reaches 1030 mAh.g(-1) corresponding to 3.5 Li with the first cE was about 85%, and 98% for the second cycle. The addition of carbon to Ti-Fe-Si-c played a key role in capacity retention. The best results were obtained for the composite Fe/Ti/Si (1:1:2) with 10 wt% of carbon, ball-milled at 500 rpm for 48 hours. The specific capacities were about 900 mAh.g(-1) at c/5 and 700 mAh.g(-1) at 1c (c = 1200 mAg(-1)) with a capacity retention of about 90% for 100 cycles.

关键词： Ti-Fe-Si c Li-ion batteries ball milling anode capacity discharge charge

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Microstructure and mechanical properties of the c/c composite and Nb joints brazed with an active Ag-based filler metal

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cERAMIcS INTERNATIONAL 2022年第7期48卷 9621-9630页

作者： Zheng, K. Yang, Z. W. Wang, Y. Wang, D. P. Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Adv Joining Technol Tianjin 300072 Peoples R China Minist Educ Key Lab Adv Ceram & Machining Technol Tianjin 300350 Peoples R China

An active Ag-based filler metal, containing trace alloy elements of Al, cu and Ti, was successfully applied to braze c/c composite and Nb. The microstructure and formation mechanism of the c/c composite and Nb brazed joint were investigated in this study. Moreover, the influence of brazing parameters on microstructural evolution and mechanical properties of brazed joints was evaluated. The typical interfacial microstructure of the joint obtained at 950 degrees c for 600 s was c/c/Tic + Alcu2Ti/Ag(s, s) + Alcu2Ti + particle cu/Alcu2Ti + AlcuTi + (Ti, Nb)3Al + Nb(Ti)/Nb. The dispersive Alcu2Ti phase was uniformly distributed in the Ag matrix, which was a beneficial structure for the brazed joint. The shear strength of the brazed joint was sensitive to the brazing temperature and holding time, which was closely related to the Tic layer bordering the c/c composite. The thickness of the Tic layer first increased as temperature increased to 950 degrees c, and then decreased when temperature reached 970 degrees c. The carbon fiber eroded by the filler at 970 degrees c entered to the brazing seam and reacted with Ti, resulting the reduction of the thickness of Tic, thus damaging the strength of the joint. With extension of holding time from 300 s to 1200 s, the interface reaction became more sufficient. Therefore, the thickness of the Tic layer increased. However, at 1200 s, the over-thick Tic broke the c/c substrate because of the mismatch of coefficient of thermal expansions. The maximum shear strength of the joint (950 degrees c/600 s) reached 55 MPa at room temperature and 35 MPa tested at 550 degrees c.

关键词： c c composite Braze Mechanical properties Microstructures

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Ordered Element Distributed c3N Quantum Dots Manipulated crystallization Kinetics for 2D csPbI3 Solar cells with Ultra-High Performance

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SMALL 2022年第15期18卷 2108090-2108090页

作者： Li, Zhizai Yang, Siwei Ye, caichao Wang, Gang Ma, Bo Yao, Huanhuan Wang, Qian Peng, Guoqiang Wang, Qiang Zhang, Hao-Li Jin, Zhiwen Lanzhou Univ Sch Phys Sci & Technol Lanzhou 730000 Peoples R China Lanzhou Univ Key Lab Magnetism & Magnet Mat MoE Lanzhou 730000 Peoples R China Chinese Acad Sci Shanghai Inst Microsyst & Informat Technol State Key Lab Funct Mat Informat Lab Graphene Mat & Applicat Shanghai 200050 Peoples R China Univ Chinese Acad Sci Coll Mat Sci & Optoelect Technol Beijing Peoples R China Southern Univ Sci & Technol Acad Adv Interdisciplinary Studies Shenzhen 518055 Guangdong Peoples R China Southern Univ Sci & Technol Guangdong Prov Key Lab Computat Sci & Mat Design Shenzhen 518055 Guangdong Peoples R China Ningbo Univ Sch Phys Sci & Technol Dept Microelect Sci & Engn Ningbo 315211 Peoples R China Lanzhou Univ State Key Lab Appl Organ Chem Lanzhou 730000 Peoples R China Lanzhou Univ Key Lab Special Funct Mat & Struct Design Lanzhou 730000 Peoples R China Lanzhou Univ Coll Chem & Chem Engn Lanzhou 730000 Peoples R China

Two-dimensional (2D) csPbI3 is developed to conquer the phase-stability problem of csPbI3 by introducing bulky organic cations to produce a steric hindrance effect. However, organic cations also inevitably increase the formation energy and difficulty in crystallization kinetics regulation. Such poor crystallization process modulation of 2D csPbI3 leads to disordered phase-arrangement, which impedes the transport of photo-generated carriers and worsens device performance. Herein, a type of c3N quantum dots (QDs) with ordered carbon and nitrogen atoms to manipulate the crystallization process of 2D csPbI3 for improving the crystallization pathway, phase-arrangement and morphology, is introduced. combination analyses of theoretical simulation, morphology regulation and femtosecond transient absorption (fs-TA) characterization, show that the c3N QDs induce the formation of electron-rich regions to adsorb bulky organic cations and provide nucleation sites to realize a bi-directional crystallization process. Meanwhile, the quality of 2D csPbI3 film is improved with lower trap density, higher surface potential, and compact morphology. As a result, the power conversion efficiency (PcE) of the optimized device (n = 5) boosts to an ultra-high value of 15.63% with strengthened environmental stability. Moreover, the simple c3N QDs insertion method shows good universality to other bulky organic cations of Ruddlesden-Popper and Dion-Jacobson, providing a good modulation strategy for other optoelectronic devices.

关键词： 2D csPbI (3) c N-3 crystallization kinetics phase management

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Waste biomass derived carbon supported Mo2c/c composite materials for heavy metal adsorption and hydrogen evolution reaction

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MATERIALS TODAY cOMMUNIcATIONS 2022年 31卷

作者： Ding, Jun He, Wenzhi Yu, chao Liu, Zhenglong Deng, chengji Zhu, Hongxi Wuhan Univ Sci & Technol State Key Lab Refractories & Met Wuhan 430081 Peoples R China

Application of waste biomass resources in heavy metal adsorption and new energy development is of great significance to improving environmental pollution and the adjustment of energy structure. For this purpose, we designed a simple method for preparing porous Mo2c/c composite materials based on resource-rich biomass carbon (derived from waste pine wood) and ammonium molybdate, and successfully applied it to the above field. The effects of holding time and sintering temperature on the phase compositions and morphological structures of samples were investigated, and the heavy adsorption capacity (cr(III)) and hydrogen evolution reaction of composite materials were also studied. The results showed that porous biomass Mo2c/c composite materials had significantly higher oxidation resistance, and more prominent pore structure as compared to the pretreated biomass carbon. In addition, porous biomass Mo2c/c composite materials showed excellent adsorption performance for heavy metal cr(III) and catalytic hydrogen evolution reaction performance, its adsorption capacity and Tafel slope were 43.2 mg/g and 123.9 mV/dec, respectively.

关键词： Porous biomass Mo (2) c c Biomass carbon Heavy metal adsorption Hydrogen evolution reaction cr(III)

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虎皮楠生物碱Daphniglaucin c的AB环系合成

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有机化学 2025年第3期45卷 925-932页

作者：张晓锋 Aggeliki Roumana 毛海康徐晶哈尔滨工业大学化学与化工学院哈尔滨150001 南方科技大学化学系、深圳格拉布斯研究院、广东省催化化学重点实验室、深圳市小分子药物发现与合成重点实验室广东深圳518055

从廉价易得的原料开始, 通过铑催化[4+3]环加成以及Heck偶联等关键反应, 高效简洁地得到了Daphniglaucin c虎皮楠生物碱的AB环系, 同时, 也尝试了利用黄氏酰胺活化增环反应进行c环构筑的探索. 本工作为Daphniglaucin c型虎皮楠生物碱的... 详细信息

从廉价易得的原料开始, 通过铑催化[4+3]环加成以及Heck偶联等关键反应, 高效简洁地得到了Daphniglaucin c虎皮楠生物碱的AB环系, 同时, 也尝试了利用黄氏酰胺活化增环反应进行c环构筑的探索. 本工作为Daphniglaucin c型虎皮楠生物碱的全合成提供了一条新的思路.

关键词：虎皮楠生物碱 Daphniglaucin c 铑催化环加成 Heck偶联全合成

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