Fast, Ambient Temperature and Pressure Ionothermal Synthesis of Three-Dimensional Covalent Organic Frameworks

2018 ◽  
Vol 140 (13) ◽  
pp. 4494-4498 ◽  
Author(s):  
Xinyu Guan ◽  
Yunchao Ma ◽  
Hui Li ◽  
Yusran Yusran ◽  
Ming Xue ◽  
...  
Author(s):  
J. J. Laidler

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.


2013 ◽  
Vol 4 (21) ◽  
pp. 3753-3759 ◽  
Author(s):  
Mauro Del Ben ◽  
Mandes Schönherr ◽  
Jürg Hutter ◽  
Joost VandeVondele

Catalysts ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 63 ◽  
Author(s):  
Chun-Ying Chen ◽  
Joseph Yu ◽  
Van-Huy Nguyen ◽  
Jeffrey Wu ◽  
Wei-Hon Wang ◽  
...  

Author(s):  
Zonglong Li ◽  
Li Sheng ◽  
Chouhung Hsueh ◽  
Xiaolin Wang ◽  
Hao Cui ◽  
...  

2020 ◽  
Author(s):  
Thaksen Jadhav ◽  
Yuan Fang ◽  
Cheng-Hao Liu ◽  
Afshin Dadvand ◽  
Ehsan Hamzehpoor ◽  
...  

We report the first transformation between crystalline vinylene-linked two-dimensional (2D) polymers and crystalline cyclobutane-linked three-dimensional (3D) polymers. Specifically, absorption-edge irradiation of the 2D poly(arylenevinylene) covalent organic frameworks (COFs) results in topological [2+2] cycloaddition cross-linking the π-stacked layers in 3D COFs. The reaction is reversible and heating to 200°C leads to a cycloreversion while retaining the COF crystallinity. The resulting difference in connectivity is manifested in the change of mechanical and electronic properties, including exfoliation, blue-shifted UV-Vis absorption, altered luminescence, modified band structure and different acid-doping behavior. The Li-impregnated 2D and 3D COFs show a significant ion conductivity of 1.8×10<sup>−4</sup> S/cm and 3.5×10<sup>−5</sup> S/cm, respectively. Even higher room temperature proton conductivity of 1.7×10<sup>-2</sup> S/cm and 2.2×10<sup>-3</sup> S/cm was found for H<sub>2</sub>SO<sub>4</sub>-treated 2D and 3D COFs, respectively.


Nano Letters ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 7979-7988
Author(s):  
Liang Zhang ◽  
Lei-Lei Yang ◽  
Shu-Cheng Wan ◽  
Qi-Chao Yang ◽  
Yao Xiao ◽  
...  

Author(s):  
Shi Wang ◽  
Xiang-Chun Li ◽  
Tao Cheng ◽  
Yuan-Yuan Liu ◽  
Qiange Li ◽  
...  

Covalent organic frameworks (COFs) with well-tailored channels have the potential to efficiently transport ions yet remain to be explored. The ion transport capability is generally limited due to the lack...


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