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141.
Min-Jie Shi Sheng-Zhong Kou Bao-Shou Shen Jun-Wei Lang Zhi Yang Xing-Bin Yan 《中国化学快报》2014,25(6):859-864
Ionic liquid gel polymers have widely been used as the electrolytes in all-solid-state supercapacitors, but they suffer from low ionic conductivity and poor electrochemical performance. Arc discharge is a fast, low-cost and scalable method to prepare multi-layered graphene nanosheets, and as-made graphene nanosheets (denoted as ad-GNSs) with few defects, high electrical conductivity and high thermal stability should be favorable conductive additive materials. Here, a novel ionic liquid gel polymer electrolyte based on an ionic liquid (EM1MNTF2) and an copolymer (P(VDF-HFP)) was modified by the addition of ad-GNSs as an ionic conducting promoter. This modified gel electrolyte shows excellent thermal stability up to 400 ℃ and a wide electrochemical window of 3 V. An all-solid-state supercapacitor based on commercial activated carbon was fabricated using this modified ionic liquid gel polymer electrolyte, which shows obviously improved electrochemical behaviors compared with those of the corresponding all-solid-state supercapacitor using pure ionic liquid gel polymer electrolyte. Specially, smaller internal resistance, higher specific capacitance, better rate performance and cycling stability are achieved. These results indicate that the ionic liquid gel polymers modified by ad-GNSs would be promising and suitable gel electrolytes for high performance all-solid-state electrochemical devices. 相似文献
142.
143.
The photochromic mechanism of 1-phenyl-3-methyl-4-(6-hydro-4-amino-5-sulfo-2,3- pyrazine)-pyrazole-5-one has been investigated using the density functional theory(DFT). The solvent effect is simulated using the polarizable continuum model(PCM) of the self-consistent reaction field theory. According to the crystal structure of the title compound, an intramolecular proton transfer mechanism from enol to keto form was proposed to interpret its photochromism. Bader's atom-in-molecule(AIM) theory is used to investigate the nature of hydrogen bonds and ring structures. Time-dependent density functional theory(TDDFT) calculation results show that the photochromic process from enol to keto form is reasonable. The conformation and molecular orbital analysis of enol and keto forms explain why only intramolecular proton transfer is possible. The results from analyzing the energy and dipole moments of enol form, transition state and keto form in the gas phase and in different solvents have been used to assess the stability of the title compound. 相似文献
144.
Yutong Fu Xinyu Xia Yan Zhang Jinhai Ye Meidong Lang 《Colloid and polymer science》2014,292(9):2071-2082
Functional star-shaped 4-arm poly(ethylene glycol)-b-poly[(ε-caprolactone-co-γ-amino-ε-caprolactone)] (4-arm PEG-b-P(CL-co-ACL) was synthesized through ring-opening polymerization. The structure of the copolymer was confirmed by 1H NMR, Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). To further understand the copolymers, the difference of the conversion rate between ε-caprolactone (CL) and γ-(carbamic acid benzyl ester)-ε-caprolactone (CABCL) and the detailed deprotection condition were studied. The thermal property of the copolymer was analyzed by WAXR and differential scanning calorimetry (DSC), which demonstrated that the thermal property could be well adjusted. The pH-responsive behavior of the copolymers was studied in detail by dynamic light scattering (DLS), pH titration, and pyrene fluorescence methods, which indicated that it could form micelles and exhibit pH responsibility. Moreover, the copolymer was nontoxic and had good biocompatibility according to the results by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay. 相似文献
145.
Two perpendicular projections of rising bubbles were observed in counter-current downstream diverging flow. Evidently, the bubbles did not enter the boundary layer at the channel wall and a plug liquid flow assumption was acceptable in our experimental equipment. This confirmed that the experiment was appropriate for simulation of bubble rises in a quiescent liquid column. Recent data obtained by a high-speed camera permitted recording over a period of 60 s. Image analysis by a tailor-made program provided a time-series of quantities related to the position, size, and shape of bubbles. In addition to determination of the aspect ratio of the equivalent oblate ellipsoid, deviation from this shape was investigated in respect of the difference between the bubble’s centre of mass and the geometrical centre of bubble projection. Autocorrelation of the data indicated that the bubble inclination oscillated harmonically with a frequency of 5–10 Hz; cross correlation showed that the horizontal shift of the centre of mass, as well as the horizontal velocity, increased with increasing bubble inclination, and the vertical shift of the centre of mass increased with an increases in the absolute value of the bubble inclination. There is no significant phase shift in the oscillation of these quantities. The bulky bottom side of the bubbles is in accordance with the model of bubble oscillation induced by instability of the equilibrium of gravity and surface tension forces. The oscillation frequency dependence on surface forces (Eötvös number) is evident, while viscosity does not play a significant role in low-viscosity liquids. Therefore, vortex-shedding is more likely to be an effect of the oscillation and not its cause. 相似文献
146.
Andrea Preuß Marcus Korb Tobias Rüffer Jörn Bankwitz Colin Georgi Alexander Jakob Stefan E. Schulz Heinrich Lang 《无机化学与普通化学杂志》2020,646(13):670-680
The template synthesis of ethylenediamine ( 1 ) with 2-acetylcyclopentanone ( 2 ) and [Cu(OAc)2 · H2O] ( 5 ) produced [Cu(1-(2-cC5H6(O))C(Me)NCH2)2)] ( 6 ) in 82 % yield. Reaction of 5 with bis(benzoylacetone)diethylenetriamine ( 7 , = L H)[1] gave [Cu(μ-OAc)( L )(H2O)]2 ( 8 ). The solid-state structures of 6 and 8 were determined confirming that 8 possesses intra- and intermolecular hydrogen bonds resulting in a dimer formation. The thermal behavior of 6 – 8 was studied by TG and TG-MS. Under oxygen CuO was formed, whereas under Ar Cu/Cu2O ( 6 ) or Cu ( 8 ) was obtained. Complex 6 was used as CVD precursor for Cu and Cu-oxide deposition (substrate temp., 400–500 °C, N2, 60 mL · min–1; O2, 60 mL · min–1; pressure, 0.87–1.5 mbar). The as-obtained deposits show separated particles of different appearance at the substrate surface as evidenced by SEM. Non-volatile 8 was applied as spin-coating precursor for Cu and CuO formation [conc. 0.25 mol · L–1; volume 0.2 mL; 3000 rpm; depos. time 2 min; heating rate 50 K · min–1; holding time 60 min (Ar), 120 min (air) at 800 °C]. The samples on silicon consist of granulated particles (Ar) or are non-dense with a grainy topography (air). EDX and XPS measurements confirmed the formation of Cu (Ar) or CuO (O2) with up to 13 mol-% C impurity. 相似文献
147.
Sebastian Scharf Eduard Kovalski Tobias Rüffer Alexander Hildebrandt Heinrich Lang 《无机化学与普通化学杂志》2020,646(22):1820-1833
The synthesis of [Ti6O4(OiPr)8(O2CPh)8] ( 3 ) and [RuCl(N≡CR)5][RuCl4(N≡CR)2] ( 4a , R = Me; 4b , R = Ph), [Ru(N≡CPh)6][RuCl4(N≡CPh)2] ( 5 ) and [H3O][RuCl4(N≡CMe)2] ( 7a ) is discussed. Crystallization of 5 from CH2Cl2 gave trans-[RuCl2(N≡CPh)4] ( 6 ). The solid-state structures of 3 , 4a , b , 5 , 6 and 7a are reported. Complex 4b forms a 3D network, while 6 displays a 2D structure, due to π-interactions between the benzonitrile ligands. The (spectro)electrochemical behavior of 4a , b and 6 was studied at 25 and –72 °C and the results thereof are compared with [NEt4][RuCl4(N≡CMe)2] ( 7b ) and [RuCl(N≡CPh)5][PF6] ( 8 ). The electrochemical response of the cation and the anion in 4a , b are independent from each other. [RuCl(N≡CR)5]+ possesses one reversible RuII/RuIII process. However, [RuCl4(N≡CMe)2]– was shown to be prone to ligand exchange and disproportionation upon formation of either a RuIV and RuII species at 25 °C, while at –72 °C the rapid conversion of the electrochemically formed species is hindered. In situ IR and UV/Vis/NIR studies confirmed the respective disproportionation reaction products of the aforementioned oxidation and reduction, respectively. 相似文献
148.
Dr. Xi-Sha Zhang Yan-Ying Huang Jing Zhang Dr. Wei Meng Dr. Qian Peng Ruirui Kong Zhenwei Xiao Dr. Jie Liu Miaofei Huang Dr. Yuanping Yi Liangliang Chen Qingrui Fan Dr. Gaobo Lin Dr. Zitong Liu Dr. Guanxin Zhang Dr. Lang Jiang Prof. Dr. Deqing Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3557-3561
Polycyclic aromatic hydrocarbons with hexagons/pentagons or hexagons/heptagons have been intensively investigated in recent years, but those with simultaneous presence of hexagons, pentagons and heptagons remain rare. In this paper, we report dicyclohepta[ijkl,uvwx]rubicene ( DHR ), a non-benzenoid isomer of dibenzo[bc,kl]coronene with two pentagons and two heptagons. We developed an efficient and scalable synthetic method for DHR by using Scholl reaction and dehydrogenation. Crystal structure of DHR shows that the benzenoid rings, two pentagons and two heptagons are coplanar. The bond lengths analysis and the ICSS(1)zz and LOL-π calculations indicate that the incorporation of two formal azulene moieties has an effect on the conjugated structure. The π-electrons of benzenoid and pentagon rings are more delocalized. Cyclic voltammetry studies indicate that DHR shows multiple oxidation and reduction potentials. Interestingly, DHR exhibits unusual S0 to S2 absorption and abnormal anti-Kasha S2 to S0 emission. Moreover, crystals of DHR exhibit semiconducting behaviour with hole mobility up to 0.082 cm2 V−1 s−1. 相似文献
149.
Dou Ma Ping Li Xiangyu Duan Jiazhen Li Pengpeng Shao Dr. Zhongling Lang Lixia Bao Dr. Yuanyuan Zhang Dr. Zhengguo Lin Prof. Dr. Bo Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):3933-3937
Metal–organic frameworks (MOFs) with long-term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT-66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT-66 (V3(O)3(H2O)(BTB)2), possesses prominent moisture tunability in the range of 45–60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption–desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials. 相似文献
150.
Wei Zhou Jun-Kang Guo Sheng Shen Jinbo Pan Jie Tang Lang Chen Chak-Tong Au Shuang-Feng Yin 《物理化学学报》2020,36(3):1906048-0
CO_2是最常见的化合物,作为潜在的碳一资源,可用于制备多种高附加值的化学品,如一氧化碳、甲烷、甲醇、甲酸等。传统的热催化转化CO_2方法能耗高,反应条件苛刻。因此,如何在温和条件下高效地将CO_2转化成高附加值的化学品,一直以来是催化领域的研究热点和难点之一。光催化技术反应条件温和、绿色环保。然而,纯光催化反应普遍存在太阳能利用效率有限,光生载流子分离效率低等问题。针对上述问题,在光催化的基础上引入电催化,可以提高载流子的分离效率,在较低的过电位下,实现多电子、质子向CO_2转移,从而提高催化反应效率。总之,光电催化技术可以结合光催化和电催化的优势,提高CO_2催化还原反应效率,为清洁、绿色利用CO_2提供了一种新方法。本文依据光电催化CO_2还原反应基本过程,从光吸收、载流子分离和界面反应等三个角度综述了光电催化反应的基本强化策略,并对未来可能的研究方向进行了展望。 相似文献