LANGMUIR
·
2010
·
IF 3.898
Jinqiang Jiang,Qiaozhen Shu,Xin Chen,Yiqun Yang,Chenglin Yi,Xiaoqing Song,Xiaoya Liu,Mingqing Chen
A novel photosensitive C-PNIPAAm comprising hydrophilic PNIPAAm conjugated with a relatively short but very hydrophobic coumarin part was designed and prepared using a coumarin-containing disulfide derivative (C-S-S-C) as transfer agent in the presence of Bu3P and water. It was found that C-PNIPAAm can form polymer micelles in aqueous solution. And the micellar morphology in aqueous solution can be photoswitched into hollow spheres according to the photodimerization of coumarin end groups upon 365 nm irradiation and reform the micellar morphology after the subsequent photoscission of dimers upon 254 nm. This instant morphology changing phenomenon was successfully monitored by dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. TEM observations showed the small spherical shape of micelles with diameter at 30−50 nm before photo-cross-linking, the big vesicles with diameter at 200−350 nm after photo-cross-linking, and the small micelles with diameter at 30−50 nm after the subsequent photo-de-cross-linking in the first irradiation cycle. The reason for this significant morphology switching can be attributed to the reversible photoinduced amphiphilic structure transformation between the telechelic “hydrophobic end−hydrophilic chain” structure and the ABA type of “hydrophilic chain−hydrophobic center−hydrophilic chain” one upon alternating irradiation.
研究领域:
高分子化学
·
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 53
·47498-47508
·
IF 3.289
Yan Yuan,Yulin Zhang,Ren Liu,Jingcheng Liu,Zhiquan Li,Xiaoya Liu
In this study, 7-(4-vinylbenzyloxyl)-4-methylcoumarin (VM) and maleic anhydride (MA) were polymerized through free radical copolymerization to form a photosensitive alternating copolymer P(VM-alt-MA) (PVMA). PVMA was used as a soft template to achieve the oxidative polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT). We obtained a stable PEDOT:PVMA photosensitive aqueous dispersion with an average diameter in the range of 140 to 210 nm. We then used this aqueous dispersion as the ink for fabricating humidity sensors through inkjet-printing on a paper substrate. The printed photosensitive conductive film PEDOT:PVMA could be cross-linked after photo-dimerisation of coumarin groups, leading to a small decrease of electrical conductivity, but also appreciable improvements in water resistance and sensor robustness. The humidity sensing ability of these PEDOT:PVMA/paper sensors was investigated by exposing them to a wide range of relative humidity, namely 11–97% at room temperature. These paper sensors could selectively and reversibly detect water vapor with a significant linear relationship. The response strength and the response/recovery time of the sensors show a substantial improvement compared with those of previous reports. The photo-dimerisation of PEDOT:PVMA improves the stability of humidity response and the response/recovery time of the sensors.
研究领域:
材料科学
·
传感器技术
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMBIOCHEM
·
2024
·
IF 2.6
Yi Yang,Zhiyi Zhao,Xiaoying Li,Yian Chen,Lu Liu,Shao-Lin Zhang,Aimin Yang
Graphical Our study designs and synthesizes a series of peptides targeting the dimerization of SARS-CoV-2 M pro . Several peptides display potential inhibitory activities. Specifically, N8-A24 shows most efficient suppression of the M pro activity via inhibiting its dimerization. The severe acute respiratory syndrome virus 2 (SARS-CoV-2) seriously impacted public health. The evolutionarily conserved viral chymotrypsin-like main protease (M pro ) is an important target for anti-SARS-CoV-2 drug development. Previous studies have shown that the eight N-terminal amino acids (N8) of SARS-CoV M pro are essential for its dimerization, and are used to design inhibitors against SARS-CoV M pro dimerization. Here, we established a simple readout assay using SDS-PAGE and Coomassie blue staining to measure inhibitory activity of N8 peptide derived from SARS-CoV-2 M pro . To optimize its inhibitory effect, we then modified the side-chain length, charge, and hydrophilicity of the N8 peptide, and introduced a mutated M pro recognition sequence. As a result, we obtained a series of potent peptide inhibitors against SARS-CoV-2 M pro , with N8-A24 being the most efficient with an IC 50 value of 1.44 mM. We observed that N8-A24 reduced M pro dimerization with an IC 50 value of 0.86 mM. Molecular docking revealed that N8-A24 formed hydrogen bond interactions with critical dimeric interface residues, thus inhibiting its dimerization and activity. In conclusion, our study not only discovers a series of peptide inhibitors targeting the SARS-CoV-2 M pro dimerization, but also provides a promising strategy for the rational design of new inhibitors against COVID-19.
研究领域:
病毒学
·
药物开发
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Wei Du,Yiping Liu,Yifang Gao,Longjing Bai,Lei Zhang,Penggao Cheng,Na Tang
To further probe into the link between solution chemistry and nucleation processes experimental and computational data are presented on unsaturated, saturated, and supersaturated solutions and in situ monitoring of nucleation chemistry of p-chlorobenzoic acid (PCBA), p-methoxybenzoic acid (PMBA) and p-nitrobenzoic acid (PNBA), three benzoic acid derivatives with different properties of para-substituents. By variation of the gas media, we were able to establish that hydrogen-bonded dimers (HD) are the basic building unite in solution for clusters and nucleuses despite of the gases and solvents, and there is a strong link between the supersaturated solution chemistry and the intrinsic supersaturation ratio, and the nucleation kinetics. Two different molecular self-assembly pathways and the rate-controlling steps were discussed, which paves new aspects for understanding the role of solution chemistry in directing nucleation processes.
研究领域:
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Bin Pu,Gaolang Xiao,Juying Xiao,Hua-Bing Yin,Jin Wang
Self-healing materials based on photodimerization have advantages such as being fast, efficient, environmentally friendly and controllable. However, most of photoresponsive self-healing materials suffer from a problem that there is a compromise between the strength and the self-healing efficiency. Therefore, most of the research focuses on using flexible materials to reach high self-healing efficiency. The absorption wavelengths of some photosensitive groups are narrow, which limits the application fields of self-healing properties of self-repairing materials. Here, we use photodimerizable thymine as the photoresponsive group and exploit the sensitivity of a methoxyacetophenone photosensitizer to increase the self-healing efficiency of a rigid membrane material from beyond repairing to 85% recovery under the same conditions. The tensile strength of the self-healing material is 33.88 MPa, and the elastic modulus reaches 3 GPa after 80 min of photo-irradiation at 308 nm. The maximum thermogravimetric decomposition rate temperature exceeds 400 °C, exhibiting their excellent thermal stability. This strategy provides a novel and effective approach to endow rigid materials with high self-healing efficiency at benign conditions, and opens a new avenue to functionalise a wide range of rigid engineering materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2018
·Vol. 29
·期 7
·1516-1526
·
IF 1.444
Huang Xue,Yin Yaoqi,Zhang Buning,Feng Guangzhu
The effects of structure and composition of different montmorillonites on their catalytic performance in the dimerization of unsaturated fatty acids were investigated. The dimerization reaction was performed at 240 ºC for 3 h, with montmorillonite as catalyst, and LiCl as the co-catalyst. The results showed that the specific surface areas of the different montmorillonites did not have a major effect on their catalytic performance, but the interlayer spacing and surface acidity of montmorillonite show significant effects on the product yield. After the organic modification through hexadecyl trimethyl ammonium bromide (CTAB) intercalation, the microenvironment of the montmorillonite layer changes. Moreover, the inner and outer surfaces change from being hydrophilic to lipophilic, which improves the dispersibility of montmorillonite in fatty acids. The xAl/xSi molar ratios of the three samples are similar and lie within the range of 0.4306-0.5010, thus the xAl/xSi molar ratio has little effect on the dimerization reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2018
·
IF 5.914
Zhukang Du,Xiaolong Yan,Renfeng Dong,Kang Ke,Biye Ren,Zhen Tong
Telechelic associative polymers (TAPs) can form a dynamic transient network in water and have been widely used as rheological modifiers for improving solution rheological properties in many industrial fields. In this work, we designed and prepared a novel photoresponsive coumarin-functionalized telechelic associative model polymer (CouTAP), which was used to investigate the influence of light-induced dimerization of coumarin end groups on the polymer structure and solution rheological properties. The effects of light intensity, irradiation time, polymer concentration, and temperature on the transient network and rheological behavior of the CouTAP aqueous solution were studied in detail. The rheological properties of the dimerized CouTAP aqueous solution show weak temperature dependence, and the dynamics hardly depends on concentration due to the transformation of triblock to multiblock polymers. A novel transient network model composed of train loops and bridges covalently linked to train loops was proposed to describe the unique solution properties. This work will not only provide new insights into the influence of the light-induced dimerization of coumarin end groups on the network structure and rheological properties of CouTAP solution but also opens a new perspective for the controlled self-assembly of amphiphilic polymers and some special applications of TAPs in the manufacturing and transmission of soft materials, waterborne coating, inks, medicines, cosmetics, and so on.
研究领域:
高分子化学
·
材料科学
·
流变学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Guo Liu,Shan Huang,Xiaochen Liu,Wanzhen Chen,Xin Ma,Shuang Cao,Liping Wang,Lanlan Chen,Huanghao Yang
Transmembrane signal transduction is of profound significance in many biological processes. The dimerization of cell-surface receptors is one prominent mechanism by which signals are transmitted across the membrane and trigger intracellular cascade amplification reactions. Recreating such processes in artificial systems has potential applications in sensing, drug delivery, bioengineering, and providing a new route for a deep understanding of fundamental biological processes. However, it remains a challenge to design artificial signal transduction systems working by the receptor dimerization mechanism in a predictable and smart manner. Here, benefitting from DNA with features of programmability, controllability, and flexible design, we use DNA as a building material to construct an artificial system mimicking dimerization of receptors for signal transduction and cascade amplification. DNA-based membrane-spanning receptor analogues are designed to recognize external signals, which drives two receptors into close spatial proximity to activate DNAzymes inside the cell-mimicking system. The activation of the DNAzyme initiates the catalyzed cleavage of encapsulated substrates and leads to the release of fluorescent second messengers for signal amplification. Such an artificial signal transduction system extends the range of biomimetic DNA-based signaling systems, providing a new avenue to study natural cell signaling processes and artificially regulate biological processes.
研究领域:
合成生物学
·
分子生物学
·
纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Xu Li,Jiaqi Li,Xiaohong Wang,Lijun Yang,Hong Xu,Jinxiang Dong
Despite the significant progress that has been made regarding the purification of C5–C9 linear α-olefins from the liquid products of Fischer–Tropsch synthesis, the energy-consuming separation of olefins and paraffins with the same carbon number has restricted their industrial development. Herein, we first propose a reaction-separation-utilization integrated process that combines the zirconocene/methylalumoxane-catalyzed selective dimerization of linear α-olefins to α-olefin dimers, which can then be separated from paraffins in FTS liquid products via conventional distillation and catalytically converted into branched-chain sulfonate surfactants through homogeneously organocatalytic sulfonation with sodium bisulfite. The resulting branched-chain sulfonates have been characterized by FTIR, HPLC , LC-MS, HR-MS, and NMR techniques. Their surfactant properties, including equilibrium surface tension, dynamic surface tension , foaming property, wetting ability, and emulsifying power, and detergency performance, have been thoroughly investigated. The results showed that the resulting branched-chain sulfonate surfactants exhibit superior surfactant properties and detergency performance in comparison with commercially applied linear alkylbenzene sulfonate (LAS). In view of the growing demand for anionic surfactants in the detergent and cosmetics industries , this study represents a new route for the use of α-olefins from the Fischer–Tropsch synthesis for the production of branched-chain surfactants.
研究领域:
化学工程
·
材料科学
·
工业化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Jiyuan Li,Zhuxiu Zhang,Mifen Cui,Qing Liu,Zhaoyang Fei,Xian Chen,Jihai Tang,Xu Qiao
The acid-catalyzed Markovnikov addition of isobutene is affected by the concomitant isobutene oligomerization. Herein, a solid acid catalyst consisting of the sulfonated silica modified with crystalline ZrSiO 4 was prepared, and the ZrSiO 4 /SiO 2 -SO 3 H catalyst went beyond conventional acid catalysts in the hydroacetoxylation of isobutene. The structure of the catalyst was well-characterized, and the role of ZrSiO 4 in suppressing the dimerization of isobutene was discussed in terms of both kinetic study and in-situ DRIFT analysis. Moreover, this catalyst also showed general applicability for a broad substrate scope, further highlighting the necessity of ZrSiO 4 in the solid acid catalyst.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2014
·Vol. 293
·期 3
·823-831
·
IF 2.41
Chang Huan,Liu Yan,Shi Mei,Liu Zhaotie,Liu Zhongwen,Jiang Jinqiang
The water-soluble amphiphilic random copolymer of P(DMA- co -VBC) with coumarin pendants has been designed to investigate the photo-induced dynamic association of coumarin pendants within polymer micelles in aqueous solution. Methods of absorption and emission spectra, solution transmittance, dynamic light scattering (DLS), and atomic force microscope (AFM) were applied. It was found that P(DMA- co -VBC) can form polymer micelles in aqueous solution. The time-dependent photo-dimerization degree (PD) of polymer micelles upon different intensity irradiations of 320 nm light showed saturating behaviors with an intensity-independent value of the maximum photo-dimerization extent, while the maximum photo-cleavage extent of coumarin dimers declined with the increasing intensity of 254 nm irradiation at used conditions. Furthermore, a significant emission band at 445 nm ( I
2
) evidently emerged as against the disappearance of emission band at 385 nm ( I
1 ) during the photo-dimerization, and the time-dependent I
2
/I
1 ratios of polymer aqueous solution upon alternative irradiations of 320 and 254 nm light showed a wave-like increase as a function of irradiation cycles, indicating a wavy closeness of coumarin pendants within polymer micelles during the reversible photo-dimerization cycles.
研究领域:
高分子化学
·
光化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Yiyang Gu,Chunyu Ru,Zhen Zhao,Danming Chao,Xincai Liu
Shape memory polymers have attracted much attention due to their promising applications in biomedicine, textiles, aerospace et al. Here, novel poly(aryl ether ketone)s bearing flexible alkyl segments and pendant anthracene groups were synthesized via nucleophilic copolycondensation coupled with post-polymerization functionalization. Their chemical structure, thermostability and mechanical properties were characterized through Fourier Transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermal gravimetric analysis and dynamic mechanical analysis. The soft-rigid alternative segment structure endows these poly(aryl ether ketone)s with promising shape memory properties. After the photodimerization of pendant anthracene units, the resultant polymers exhibit enhanced shape memory performance in terms of satisfying shape fixity ratio and high shape recovery ratio, attributed to their photocrosslinked polymeric network architecture. This shape memory polymer with reversible photodimerization holds great promise for a deep understanding of the mechanism and future applications.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）