scholarly journals A Cathodic Electrochromic Material Based on Thick Perylene Bisimide Film with High Optical Contrast and High Stability

CCS Chemistry ◽  
2021 ◽  
pp. 1763-1772
Author(s):  
Jianqiao Wang ◽  
Weitao Ma ◽  
Hailong Wang ◽  
Zengqi Xie ◽  
Huanhuan Zhang ◽  
...  
Keyword(s):  
High Stability ◽  
Optical Contrast ◽  
Perylene Bisimide ◽  
Electrochromic Material

scholarly journals Substituent-Adjusted Electrochromic Behavior of Symmetric Viologens

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1702
Author(s):  
Qun Zhang ◽  
Li Yuan ◽  
Fanglan Guan ◽  
Xin Li ◽  
Rui Wang ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Response Time ◽  
Electrochemical Properties ◽  
Chain Length ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Redox Activity ◽  
Optical Contrast ◽  
Electrochromic Material ◽  
Bleaching Response

As a promising electrochromic material, viologens have attracted increasing attention due to their high redox activity and adjustable electrochromic capability. In order to investigate the effect of alkyl substituents on electrochromic behavior, four alkyl-substituted viologens and a benzyl-substituted viologen were synthesized, namely 1,1′-dioctyl-4,4′-bipyridinium dibromide (OV), 1,1′-didekyl-4,4′-bipyridinium dibromide (DeV), 1,1′-didodecyl-4,4′-bipyridinium dibromide (DoV), 1,1′-dihexadecyl-4,4′-bipyridinium dibromide (HV), and 1,1′-dibenzyl-4,4′-bipyridinium dibromide (BV). The different photophysical and electrochemical properties of these viologens were attributed to their deviation in spatial structure caused by different substituents. Compared with benzyl-substituted BV, a slight blueshift occurred for the absorption peaks of alkyl-substituted viologens from 262 to 257 nm with the increase in alkyl chain length. Moreover, the first redox couple increased positively, and the dimerization of the compound decreased gradually, accompanied by the decrease in optical contrast and distinct chromatic difference. A comparison of chromatic and optical contrasts indicated that OV had the longest coloring response time (RTc), while it was shortest for HV. The bleaching response time (RTb) of viologen films gradually decreased with the alkyl chain length, and the OV film had the shortest RTb. Furthermore, when increasing the length of the alkyl chain, the cycling stabilities of alkyl viologens increased gradually. In addition, the OV film exhibited the best contrast after 200 continuous cycles.

Real-life Field Studies of the NOx Removing Properties of Photocatalytic Surfaces in Roskilde and Copenhagen Airport, Denmark

2020 ◽  
Vol 01 ◽  
Author(s):  
Henrik Jensen ◽  
Pernille D. Pedersen
Keyword(s):  
Air Quality ◽  
High Stability ◽  
Reference Site ◽  
Real Life ◽  
Field Studies ◽  
The Real ◽  
Before And After ◽  
Parking Lot ◽  
Photocatalytic Concrete

Aims: To evaluate the real-life effect of photocatalytic surfaces on the air quality at two test-sites in Denmark. Background: Poor air quality is today one of the largest environmental issues, due to the adverse effects on human health associated with high levels of air pollution, including respiratory issues, cardiovascular disease (CVD), and lung cancer. NOx removal by TiO2 based photocatalysis is a tool to improve air quality locally in areas where people are exposed. Methods: Two test sites were constructed in Roskilde and Copenhage airport. In Roskilde, the existing asphalt at two parking lots was treated with TiO2 containing liquid and an in-situ ISO 22197-1 test setup was developed to enable in-situ evaluation of the activity of the asphalt. In CPH airport, photocatalytic concrete tiles were installed at the "kiss and fly" parking lot, and NOx levels were continuously monitored in 0.5 m by CLD at the active site and a comparable reference site before and after installation for a period of 2 years. Results: The Roskilde showed high stability of the photocatalytic coating with the activity being largely unchanged over a period of 2 years. The CPH airport study showed that the average NOx levels were decreased by 12 % comparing the before and after NOx concentrations at the active and reference site. Conclusion: The joined results of the two Danish demonstration projects illustrate a high stability of the photocatalytic coating as well as a high potential for improvements of the real-life air quality in polluted areas.

Endo-D-galacturonanase immobilized by adsorption on porous polyethyleneterephthalate

1982 ◽  
Vol 47 (10) ◽  
pp. 2716-2723 ◽  
Author(s):  
Lubomíra Rexová-Benková ◽  
Jiřina Omelková ◽  
Vladimír Kubánek
Keyword(s):  
Ionic Strength ◽  
High Stability ◽  
Relative Activity ◽  
Operational Stability ◽  
The Other ◽  
Fixation Strength ◽  
Action Pattern ◽  
Salt Solutions ◽  
Buffer Solution ◽  
Degradation Degree

Endo-D-galacturonanase of Aspergillus sp. was irreversibly adsorbed on polyethyleneterephthalate in an acetate 0.1 mol l-1 buffer solution of pH 4.2. Immobilization of the enzyme resulted in lowering of its activity, the measure of which depended on the amount of the enzyme fixed on the carrier. The highest relative activity (42.4%) had the preparation containing 5.25 mg of the enzyme per 1 g of the carrier. The velocity and intensity of the sorption of the enzyme depended on the ionic strength of the medium, whilst pH, on the other hand, was of no influence. Endo-D-galacturonanase immobilized in a 0.1 mol l-1 buffer was characteristic a) of its fixation strength in salt solutions of various ionic strength and pH, in a 3 mol l-1 guanidine solution, and also in sodium pectate and pectin solutions, b) of its high stability during a long-lasting storage at 4 °C, c) of its operational stability. The immobilization led to a partial change of the action pattern onto the high-molecular substrate, manifested in lowering the decrease of viscosity to degradation degree ratio.

Stability of radical anions derived from substituted 5-nitrofurans investigated by ESR spectroscopy

1985 ◽  
Vol 50 (7) ◽  
pp. 1594-1601 ◽  
Author(s):  
Jiří Klíma ◽  
Larisa Baumane ◽  
Janis Stradinš ◽  
Jiří Volke ◽  
Romualds Gavars
Keyword(s):  
Radical Anion ◽  
High Stability ◽  
Esr Spectroscopy ◽  
Reaction Path ◽  
Order Reaction ◽  
Second Order ◽  
Radical Anions ◽  
Second Order Reaction ◽  
Unpaired Electron Density ◽  
The Stability

It has been found that the decay in dimethylformamide and dimethylformamide-water mixtures of radical anions in five of the investigated 5-nitrofurans is governed by a second-order reaction. Only the decay of the radical anion generated from 5-nitro-2-furfural III may be described by an equation including parallel first- and second-order reactions; this behaviour is evidently caused by the relatively high stability of the corresponding dianion, this being an intermediate in the reaction path. The presence of a larger conjugated system in the substituent in position 2 results in a decrease of the unpaired electron density in the nitro group and, consequently, an increase in the stability of the corresponding radical anions.

Superflexible C68-graphyne as a promising anode material for lithium-ion batteries

2019 ◽  
Vol 7 (29) ◽  
pp. 17357-17365 ◽  
Author(s):  
Bozhao Wu ◽  
Xiangzheng Jia ◽  
Yanlei Wang ◽  
Jinxi Hu ◽  
Enlai Gao ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
Carrier Mobility ◽  
High Stability ◽  
High Capacity ◽  
Lithium Ion

A new graphyne with high stability, excellent flexibility and carrier mobility is theoretically predicted as a promising anode material for lithium-ion batteries with high capacity.

scholarly journals Correction: Reversible fluorescence modulation through the photoisomerization of an azobenzene-bridged perylene bisimide cyclophane

2021 ◽  
Author(s):  
Guanghui Ouyang ◽  
David Bialas ◽  
Frank Würthner
Keyword(s):  
Perylene Bisimide ◽  
Fluorescence Modulation

Correction for ‘Reversible fluorescence modulation through the photoisomerization of an azobenzene-bridged perylene bisimide cyclophane’ by Guanghui Ouyang et al., Org. Chem. Front., 2021, DOI: 10.1039/D0QO01635G.

Sign in / Sign up

Export Citation Format

Share Document