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1. chinaXiv:201705.00533 [pdf]

Silicon Oxycarbide/Carbon Nanohybrids with Tiny Silicon Oxycarbide Particles Embedded in Free Carbon Matrix Based on Photoactive Dental Methacrylates

Wang, MM [Wang, Meimei][ 1,2 ]; Xia, YG [Xia, Yonggao][ 1 ]; Wang, XY [Wang, Xiaoyan][ 1,3 ]; Xiao, Y [Xiao, Ying][ 1 ]; Liu, R [Liu, Rui][ 4,5 ]; Wu, Q [Wu, Qiang][ 6 ]; Qiu, B [Qiu, Bao][ 1 ]; Metwalli, E [Metwalli, Ezzeldin][ 7 ]; Xia, SL [Xia, Senlin][ 7 ]; Yao, Y [Yao, Yuan][ 7 ]; Chen, GX [Chen, Guoxin][ 1 ]; Liu, Y [Liu, Yan][ 1 ]; Liu, ZP [Liu, Zhaoping][ 1 ]; Meng, JQ [Meng, Jian-Qjang][ 3 ]; Yang, ZH [Yang, Zhaohui][ 6 ]; Sun, LD [Sun, Ling-Dong][ 4,5 ]; Yan, CH [Yan, Chun-Hua][ 4,5 ]; Muller-Buschbaum, P [Mueller-Buschbaum, Peter][ 7 ]; Pan, J [Pan, Jing][ 2 ]; Cheng, YJ [Cheng, Ya-Jun][ 1 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

A new facile scalable method has been developed to synthesize silicon oxycarbide (SiOC)/carbon nanohybrids using difunctional dental methacrylate monomers as solvent and carbon source and the silane coupling agent as the precursor for SiOC. The content (from 100% to 40% by mass) and structure (ratio of disor- dered carbon over ordered carbon) of the free carbon matrix have been systematically tuned by varying the mass ratio of methacryloxy- propyltrimethoxysilane (MPTMS) over the total mass of the resin monomers from 0.0 to 6.0. Compared to the bare carbon anode, the introduction of MPTMS significantly improves the electrochemical performance as a lithium-ion battery anode. The initial and cycled discharge/charge capacities of the SiOC/C nanohybrid anodes reach maximum with the MPTMS ratio of 0.50, which displays very good rate performance as well. Detailed structures and electrochemical performance as lithium-ion battery anodes have been systematically investigated. The structure?property correlation and corresponding mechanism have been discussed.

submitted time 2017-05-02 Hits973Downloads606 Comment 0

2. chinaXiv:201705.00466 [pdf]

Template-free synthesis of titania architectures with controlled morphology evolution

Cheng, T [Cheng, Ting][ 1,2 ]; Zhang, GQ [Zhang, Guoqiang][ 3 ]; Xia, YG [Xia, Yonggao][ 1 ]; Ji, Q [Ji, Qing][ 1 ]; Xiao, Y [Xiao, Ying][ 1 ]; Wang, XY [Wang, Xiaoyan][ 1,4 ]; Wang, MM [Wang, Meimei][ 1,2 ]; Liu, R [Liu, Rui][ 5,6 ]; Qiu, B [Qiu, Bao][ 1 ]; Chen, GX [Chen, Guoxin][ 1 ]

Template-free synthesis of TiO2 architectures with controlled morphology evolution has been developed through solvothermal reaction in 1,4-dioxane. By simply varying the molar ratio of the concentrated HCl over Titanium isopropoxide [TTIP] from 0 to 5.0,

submitted time 2017-05-02 Hits646Downloads371 Comment 0

3. chinaXiv:201705.00373 [pdf]

Porous titania/carbon hybrid microspheres templated by in situ formed polystyrene colloids

Cheng, T [Cheng, Ting][ 1,2 ]; Zhang, GQ [Zhang, Guoqiang][ 3 ]; Xia, YG [Xia, Yonggao][ 1 ]; Sun, ZC [Sun, Zaicheng][ 3 ]; Yang, ZH [Yang, Zhaohui][ 4 ]; Liu, R [Liu, Rui][ 5,6 ]; Xia, SL [Xia, Senlin][ 7 ]; Metwalli, E [Metwalli, Ezzeldin][ 7 ]; Xiao, Y [Xiao, Ying][ 1 ]; Wang, XY [Wang, Xiaoyan][ 1,8 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

A new strategy to synthesize hierarchical, porous titania/carbon [TiO2/C] hybrid microspheres via solvothermal reaction in N,N′-dimethyl formamide [DMF] has been developed. In situ formed polystyrene [PS] colloids have been used as templating agent and carbon source, through which TiO2/PS microspheres with a diameter of ca. 1 μm are built by packed TiO2 nanoparticles of tens of nanometers. The TiO2/PS microspheres are converted to TiO2/C microspheres with different amounts of carbon under controlled calcination condition. The mechanism investigation unveils that the introduction of concentrated HCl creates surface tension between PS and DMF, leading to the formation of PS colloids in solution. The solvothermal treatment further promotes the formation of PS colloids and integration of the titania nanoparticles within the PS colloids. The morphology, crystallinity, nature and content of carbon, UV–Vis absorption, carbon doping, pore size distribution, pore volume, and BET surface area of the TiO2 microspheres with different amounts of carbon have been measured. The applications of the TiO2/C hybrid microspheres as photo catalyst for water splitting and lithium-ion battery anode have been demonstrated. Superior photo catalytic activity for hydrogen conversion under both full spectrum and visible light illumination compared to commercial P25 has been observed for the TiO2/C microspheres with 2 wt% of carbon. Besides, the TiO2/C microspheres with 8 wt% of carbon as lithium-ion battery anode showed a much higher capacity than the bare TiO2 microsphere anode. The origin for the enhanced performance as photo catalyst and lithium-ion battery anode is discussed.

submitted time 2017-05-02 Hits395Downloads239 Comment 0

4. chinaXiv:201705.00371 [pdf]

Green Facile Scalable Synthesis of Titania/Carbon Nanocomposites: New Use of Old Dental Resins

Xiao, Y [Xiao, Ying][ 1 ]; Wang, XY [Wang, Xiaoyan][ 1,2 ]; Xia, YG [Xia, Yonggao][ 1 ]; Yao, Y [Yao, Yuan][ 3 ]; Metwalli, E [Metwalli, Ezzeldin][ 3 ]; Zhang, Q [Zhang, Qian][ 1 ]; Liu, R [Liu, Rui][ 4,5 ]; Qiu, B [Qiu, Bao][ 1 ]; Rasool, M [Rasool, Majid][ 3 ]; Liu, ZP [Liu, Zhaoping][ 1 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

A green facile scalable method inspired by polymeric dental restorative composite is developed to synthesize TiO2/carbon nanocomposites for manipulation of the intercala- tion potential of TiO2 as lithium-ion battery anode. Poorly crystallized TiO2 nanoparticles with average sizes of 4?6 nm are homogeneously embedded in carbon matrix with the TiO2 mass content varied between 28 and 65%. Characteristic discharge/ charge plateaus of TiO2 are significantly diminished and voltage continues to change along with proceeding discharge/charge process. The tap density, gravimetric and volumetric capacities, and cyclic and rate performance of the TiO2/C composites are effectively improved.

submitted time 2017-05-02 Hits522Downloads317 Comment 0

5. chinaXiv:201605.01244 [pdf]

Structural Insights into the Molecular Recognition between Cerebral Cavernous Malformation 2 and Mitogen-Activated Protein Kinase Kinase Kinase 3

Wang, Xiaoyan; Hou, Yanjie; Deng, Kai; Zhang, Ying; Wang, Da-Cheng; Ding, Jingjin; Wang, Xiaoyan; Deng, Kai
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

Cerebral cavernous malformation 2 (CCM2) functions as an adaptor protein implicated in various biological processes. By interacting with the mitogen-activated protein kinase MEKK3, CCM2 either mediates the activation of MEKK3 signaling in response to osmotic stress or negatively regulates MEKK3 signaling, which is important for normal cardiovascular development. However, the molecular basis governing CCM2-MEKK3 interaction is largely unknown. Here we report the crystal structure of the CCM2 C-terminal part (CCM2ct) containing both the five-helix domain (CCM2ct(s)) and the following C-terminal tail. The end of the C-terminal tail forms an isolated helix, which interacts intramolecularly with CCM2ct(s). By biochemical studies we identified the N-terminal amphiphilic helix of MEKK3 (MEKK3-n(helix)) as the essential structural element for CCM2ct binding. We further determined the crystal structure of CCM2ct(s)-MEKK3-n(helix) complex, in which MEKK3-n(helix) binds to the same site of CCM2ct(s) for CCM2ct intramolecular interaction. These findings build a structural framework for understanding CCM2ct-MEKK3 molecular recognition.

submitted time 2016-05-11 Hits1746Downloads942 Comment 0

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