RSC Advances
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2020
·Vol. 10
·期 7
·3726-3733
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IF 3.119
Jing Wang,Qian Jiang,Xingtian Hao,Hongchao Yan,Haiyan Peng,Bijin Xiong,Yonggui Liao,Xiaolin Xie
Stimuli-responsive supramolecular gels have been widely investigated, but the construction of a liquid crystalline gel with a high mechanical property and reversible photo-response still remains a challenge. This is due to the difficulty of designing gelators with liquid crystal properties and gelation abilities in organic solvents simultaneously. In this study, an azobenzene-containing main-chain polyester (Azo-mLCP) with a pendant amide group was synthesized. The organogel of Azo-mLCP via a hydrogen bond in dioxane possessed reversible thermal- and photo-responsive behaviours. The organogel exhibited a good self-supporting ability when the concentration of the gelator was more than 7.5 wt%. The rapid trans-to-cis isomerization of Azo-mLCP in solution was studied via UV-Vis absorption spectra. In addition, the gel-to-sol transition of the organogel could be triggered efficiently by an incomplete trans-to-cis conversion strategy. This study opens a way for the main-chain liquid crystalline polymers to serve in potential applications in photo-responsive robust actuators, electro-optical devices, and so on.
研究领域:
材料科学
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高分子化学
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光化学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
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IF 5.2
Xuefan Deng,Xun Liu,Shiyin Xia,Haixu Zhao,Yandong Liu,Qiong Ding,Haibo Zhang
Azobenzenes play an important role in dyes and pigments, food additives and pharmaceuticals. However, selective oxidation of aniline to valuable azobenzene under mild conditions is considerably challenging. Herein, through the reduction of boron clusters loaded with layered double hydroxides (LDHs), a nanometallic photocatalyst ZnTi LDH@ [ closo -B 12 H 12 ]@ 1.17%Ag(ZnTi LDH@B 12 H 12 @Ag) was synthesized. The catalyst catalyzed the synthesis of azobenzene from aniline. The catalyst achieved a high turnover frequency (TOF) of 54.9 h −1 and turnover number (TON) of 439.3. Under the reaction conditions of Na 2 CO 3 , at 40 °C and irradiation at 365 nm with an ultraviolet light source at atmospheric pressure, the yield of azobenzene reached 95.3% after 8 h of reaction and the catalytic activity remained above 80% after six recycles. This study reports a new synthetic catalyst for the selective oxidation of aniline compounds to azobenzene.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
Catalysis Science & Technology
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2019
·Vol. 9
·期 10
·2651-2663
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IF 5.726
Hairus Abdullah,Dong-Hau Kuo,Noto Susanto Gultom
Hydrogen-evolved Dy-doped Zn(O,S) photocatalysts with different amounts of Dy precursor have been synthesized, characterized and further utilized for hydrogenation reactions. The Dy catalysts are first examined using electrochemical impedance spectroscopy, photo responsivity, and the hydrogen evolution reaction. Dy-doped Zn(O,S) with 10% Dy precursor shows the best photocatalyst performance with the highest H2 production rate of 8.160 mmol g−1 h−1. This catalyst is chosen for conducting the hydrogenation reaction. It is our intention to confirm the correlation between the photocatalytic H2 production rate and the hydrogenation reactions of 4-nitrophenol to 4-aminophenol and azobenzene to aniline, which is a step further in the hydrogenation reaction to challenge the NN bond cleavage of azobenzene. A 100% photo conversion of 60 ppm azobenzene to aniline in 6 h was confirmed under a low-power UV light illumination in a 10% ethanol solution. Kinetic steps and kinetic mechanisms are proposed, which involve the important reaction steps of solvation, adsorption, pinning, and surface hydrogenation reaction operating together.
研究领域:
化学
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材料科学
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DOI
高影响因子
CHEMISTRY OF MATERIALS
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2022
·
IF 10.508
Congcong Yin,Zhe Zhang,Zhenshu Si,Xiansong Shi,Yong Wang
Constructing gated ion transport channels is of profound significance for a variety of applications but remains challenging. Covalent organic frameworks (COFs), as a new class of reticular materials, have demonstrated superiority in controllable transport and precise separation of fine species including ions. Herein, we engineer a light-responsive COF featuring intrapore azobenzene groups for highly efficient and adjustable transport of multivalent ions. Such azobenzene-tagged channels afford a customizable configuration that is precisely switchable at an angstrom level without compromising crystallinity. The membrane-shaped COFs exhibit an exceptional discrimination capability between monovalent and multivalent ions, rendering a K+/Al3+ selectivity of above 6000. Particularly, the azobenzene-decorated ordered nanochannels empower reversible, remote-controlled ion transport, implementing the tailor-made recycling of ionic adjuvants used for antibiotic production. This study reports the design and synthesis of a stimulus-responsive COF and demonstrates the efficient separation of ions by light-gated nanochannels of the smart COF.
研究领域:
材料科学
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化学工程
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生物医学工程
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DOI
高影响因子
RSC Advances
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2018
·Vol. 8
·期 65
·37348-37355
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IF 2.936
Yuxuan Zhang,Shanyong Chen
In this paper, two novel azobenzene-containing poly(aryl ether)s with different absorption wavelengths were synthesized via Ullmann coupling and Sonogashira coupling, respectively. The obtained polymers were characterized and evaluated by elemental analysis, IR, 1H NMR, UV-vis, DSC and TGA. Rare earth complexes were prepared by using the two novel azobenzene-containing poly(aryl ether)s as macromolecular ligands. The obtained rare earth complexes were characterized by elemental analysis, IR and WAXD. The influence of the absorption wavelength of azobenzene chromophores on the fluorescent properties was investigated. The polymer whose absorption wavelength was far from the excitation wavelengths of the rare earth complexes showed a much larger fluorescence intensity. By exposing the films of the rare earth complexes to two interference laser beams, SRGs can be formed on the films and can also be detected by fluorescence microscopy measurement.
研究领域:
材料科学
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光学
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DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2015
·Vol. 51
·期 5
·2727-2738
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IF 2.371
Wu Xiwen,Liu Libin,Fang Wenyuan,Qiao Congde,Li Tianduo
Abstract In this work, we synthesized two kinds of polyurethanes with azobenzene as hard segments in the side chains and in the main chains. Their thermal stabilities were high enough for their shape memory application. For polyurethane with azobenzene in the side chain (PU), the azobenzene has more distinctly effect on inhibiting crystallization of polycaprolactone (PCL) because of irregular orientation of azobenzene. For polyurethane with azobenzene in the main chain (PUR), the crystallinity of PCL is mainly affected by its molecular weight. PU-3500 and PUR-3500 exhibit perfect shape fixing ability of 99 % with recovery ratio of 98 % at 50 % strain. The recovery ratio is decreased for PU-3500 and increased for PUR-3500 as the applied strain increased. The mechanism of the hard segment structures effect on the shape memory behavior is briefly discussed. Importantly, the two molecules behave trans–cis isomerization under UV irradiation. This work is crucially important for the structural design of shape memory polyurethane and applications in the smart devices. Graphical Abstract
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
Polymer Chemistry
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2017
·Vol. 8
·期 18
·2764-2772
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IF 5.375
Zhiliang Gao,Mengjun Chen,Yuanyuan Hu,Shuli Dong,Jiwei Cui,Jingcheng Hao
We report the synthesis and assembly of light-responsive supramolecular polymer brushes based on the host–guest interaction between β-cyclodextrin (β-CD) on star-like side chains and azobenzene groups on a polymer backbone. The fraction of the hydrophilic–hydrophobic units can be easily controlled via changing the ratio of host and guest molecules. The supramolecular polymer brushes can self-assemble into unimolecular micelles, multi-molecular micelles, and vesicles with tunable sizes from 28 to 300 nm in water, respectively, with the decrease of β-CD side chains. The assemblies of micelles or vesicles can be disassembled by the trigger of UV light irradiation due to the responsive azobenzene groups. In addition, the phase transition temperature of the supramolecular polymer brushes increases with the decrease of the side chains. The micelles or vesicles can further assemble into strawberry superstructures by increasing the temperature. Our work provides a platform for the generation of assemblies across a wide range of scales, from polymer brushes to micelles or vesicles and superstructures.
研究领域:
材料科学
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高分子化学
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纳米技术
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DOI
高影响因子
MATERIALS LETTERS
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2020
·
IF 3.204
Wei Wang,Dan Feng,Yue Zhang,Ling Lin,Haiyan Mao
An eco-friendly halochromic smart polymer was fabricated via covalently introducing azobenzene moieties into castor oil-based waterborne polyurethane . Infrared spectrum and thermogravimetric analysis have confirmed the successful incorporation of azobenzene moieties into polyurethane chains. The halochromic polymer undergoes color change from yellow to amaranth due to the structure shifting from azo form to hydrazine form at pH < 5, showing a visually detectable color difference with the naked eyes. It is also found that the color is reversible by neutralizing treatment and the switching process can be repeated more than 10 times. This eco-friendly halochromic polymer is expected to prepare wearable and visual pH sensor as environment, health and food monitors.
研究领域:
材料科学
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化学工程
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环境科学
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产品关联
DOI
高影响因子
Light-Science & Applications
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2021
·Vol. 10
·期 1
·1-9
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IF 17.782
Chen Baiyi,Zhang Rongrong,Hou Yaqi,Zhang Jian,Chen Shiyan,Han Yuhang,Chen Xinyu,Hou Xu
Safe and precise control of gas flow is one of the key factors to many physical and chemical processes, such as degassing, natural gas transportation, and gas sensor. In practical application, it is essential for the gas-involved physicochemical process to keep everything under control and safe, which significantly relies on the controllability, safety, and stability of their valves. Here we show a light-responsive and corrosion-resistant gas valve with non-thermal effective liquid-gating positional flow control under a constant pressure by incorporating dynamic gating liquid with light responsiveness of solid porous substrate. Our experimental and theoretical analysis reveal that the photoisomerization of azobenzene-based molecular photoswitches on the porous substrate enabled the gas valve to possess a light-responsive and reversible variation of substantial critical pressure of non-thermal effective gas flow switch. Moreover, the chemically inert gating liquid prevented the solid substrate from corrosion and, by combining with the high spatiotemporal resolution of light, the gas valve realizes a precisely positional open and close under a steady-state pressure. The application demonstrations in our results show the potentials of the new gas valve for bringing opportunities to many applications, such as gas-involved reaction control in microfluidics, soft actuators, and beyond.
研究领域:
材料科学
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化学工程
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光学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
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2021
·Vol. 9
·期 40
·14139-14145
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IF 7.393
Yuxuan Zhang,Xue Zhao,Jianhang Yuan,Xialei An,Xuefang Sun,Jie Yi,Xi-Ming Song
The research on the photomechanical effects of azobenzene-containing high performance polymer materials has received much attention due to their potential applications in high temperature environments. At present, there are few types of photoinduced deformable polymers based on azobenzene-containing high performance polymers, and their photoinduced deformation rates need to be improved. In this paper, a novel series of azobenzene-containing poly(arylene ether)s with various contents of binaphthalene groups were synthesized. Introducing binaphthalene groups into azobenzene-containing poly(arylene ether)s was a helpful strategy to increase the free volume, which could increase the photoinduced deformation rates of the polymers. Under 442 nm unpolarized laser irradiation, the photoinduced deformation rates increased with the contents of binaphthalene groups of the polymers. Under 442 nm polarized laser irradiation, the cantilevers of the azobenzene-containing poly(arylene ether)s have shown unusual photoinduced deformation behavior. When the polarization direction of the polarized laser was perpendicular to the long axis of the cantilevers of the polymers, the cantilevers bent away from the excitation laser at the beginning, then bent towards the excitation laser and could reach the initial position. The angles of the polymers bent away from the excitation laser increased with the contents of binaphthalene groups of the polymers. The photoinduced deformation behavior of the polymers could be adjusted by adjusting the polarization direction of the polarized laser, the laser power and the thickness of the cantilevers of the polymer. This interesting phenomenon has not been reported in previous research on the photoinduced deformation behavior of azobenzene-containing high performance polymers.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
Computational and Theoretical Chemistry
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2021
·
IF 1.926
Jianqiang Zhao,Yue Zhang,Lihua Gan,Guanlei Wang
Here, we combined experimental measurements and DFT calculations to study UV–vis absorption spectra. DFT calculations of azobenzene and its derivatives proved useful for estimation of experimental spectra with near one-to-one correspondence. Calculation results show that substituents have no obvious effect on the coplanarity of benzene rings and N N bond. Potential energy surfaces were calculated for DHA and DEA. In the ground state, the inversion pathway was found to be preferred. A conical intersection was found between the ground and first excited states along the rotation pathway, indicating that the rotation mechanism is favored in the first excited state for DHA and DEA. UV–vis spectra of DHA and DEA were calculated by TD-DFT. Compared with azobenzene, the calculated wavelength of maximum absorption of DHA- trans and DEA- trans has red shift in UV–vis absorption spectra, which are in reasonable agreement with the experimental data.
研究领域:
化学
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光化学
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理论计算
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2013
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IF 0.596
Wei Wang,Xiaoyu Jiang,Qiang Zhang,Mingzhu Li,Xiaolong Yu,Junwu Wang,Yan Gao
A fluorescent probe for selective detection of mercury based on an azobenzene derivative bearing naphthalene units has been synthesised and its cation recognition abilities examined by UV-Vis and fluorescence spectroscopy. The fluorescent probe exhibits a highly selective response of fluorescence enhancement toward mercury in DMF aqueous media (DMF: H2O, v/v = 1:1).
研究领域:
分析化学
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环境科学
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材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）