检索结果-南通市图书馆

OPTICAL PHASE CONJUGATION RESPONSE OF PHOTOINDUCED polymer FILMS CONTAINING azobenzene MOIETIES WITH CHIRAL GROUP

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2002年第2期20卷 99-104页

作者：范星河周其凤 Department of polymer Science and Engineering College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

An optically active monomer containing azobenzene moieties with chiral group (s-2-methyl-butyl), 4-[2-(methacryloyloxy)ethyloxy] -4'-(s-2-methyl-1-butyloxycarbonyl) azobenzene (M1) was synthesized. polymer (PM1) possessing optical phase conjugated response was obtained by homopolymerization of the optically active monomer (M1) using free radical polymerization. The polymer was very soluble in common solvents and good optical quality films could be easily fabricated by spin coating. The optical phase conjugated responses of the polymer PM1 were measured by degenerate four-wave mixing (DFWM). In comparison with polymer containing no chiral group, it was found from the preliminary measurement of photoisomeric change that optical phase conjugated response of the PM1 in the long-range order hexagonal symmetry microstructure could be easily controlled by choosing the appropriate polarization direction of the irradiating beams (514.5 nm) and the irradiating number, presumably due to the chiral group in the PM1 molecular structure. For the case of the polymer investigated here, a chiral group side chain was introduced to increase optical phase conjugated response intensity with different polarization directions of the irradiating beams, which aims originally at searching for a new photoactive material.

关键词： azobenzene polymer chiral groups degenerate four-wave mixing optical phase conjugation

PHOTOINDUCED HOLOGRAPHIC PHASE GRATINGS BURIED IN azobenzene SIDE-CHAIN polymer FILMS WITH A CHIRAL GROUP

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2003年第1期21卷 93-98页

作者：范星河周其凤 Department of polymer Science and Engineering College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

An optically active polymer (PM1) containing azobenzene moieties with a chiral group (s-2-methyl-butyl) wassynthesized by homopolymerization of monomer, 4-[2-(methacryloyloxy)ethyloxy-4'-(s-2-methyl-1-butyl oxycarbonyl)azobenzene, using the free radical polymerization method. The polymer dissolved in tetrahydrofuran (THF) could be easilyprocessed into high optical quality films. The optical anisotropy of the polymer films was investigated by polarizing opticalmicroscopy (POM). The experimental results showed that irradiation with a circularly polarized beam could align theorientation of the molecules in the polymer films. Moreover, the holographic phase gratings of photo-induced polymer filmswere detected by atomic force microscopy (AFM) and POM. In comparison with polymer containing no chiral group, it wasfound from the preliminary measurement of the photo-induced holographic phase gratings that PM1 containing a chiralgroup could form holographic phase gratings buried in the films.

关键词： Holographic phase gratings azobenzene polymer Chiral groups

Induction and modulation of supramolecular chirality in side-chain azobenzene polymers through the covalent chiral domino effect

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2021年第12期64卷 2105-2110页

作者： Lu Yin Meng Liu Haotian Ma Xiaoxiao Cheng Tengfei Miao Wei Zhang Xiulin Zhu Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationState and Local Joint Engineering Laboratory for Novel Functional Polymeric MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China

Induction,transfer,and modulation of intriguing supramolecular chirality were achieved in a chiral domino-type polymer system using a chiralα-end azobenzene(Azo)moiety as one chiral terminus and achiral Azo repeating units as building *** Azo polymers prepared by atom transfer radical polymerization were imparted with well-controlled chain lengths and a chiral moiety at a well-defined *** chiral terminus can effectively dictate the helical orientation of the achiral Azo stacks in the aggregation *** spacer length between the chiral residue and the achiral repeating units dominates the preferred handedness of the side-chain Azo *** instance,the R-configuration moiety with a short alkyl chain(with 0,2,and 3 carbons)induces right-handed supramolecular chirality,whereas those with long alkyl chains(with 4,5,and 6 carbons)induce the opposite helical orientation of the Azo ***,the chiral regulation of polymer aggregates is successfully achieved using the unique photoisomerization transition of the Azo chromophore and the heat-assisted reassembly *** induction and chiral-to-achiral communication are further verified via theoretical simulations.

关键词： covalent chiral domino effect supramolecular chirality azobenzene polymer chiral induction chiral modulation

Photorheological fluids of azobenzene polymers for lubrication regulation

在线全文

学校读者我要写书评

暂无评论

Friction 2022年第7期10卷 1078-1090页

作者： Shuangxi TANG Shayu LI Liran MA Yu TIAN State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 401331China

Fluid viscosity is ubiquitous property and is of practical importance in intelligent fluids,industrial lubrication,and pipeline fluid ***,there has been a surging interest in viscosity ***,we have developed a group of photorheological fluids by utilizing azobenzene polymers with a light-induced microstructure *** this work,a photosensitive polymer with 4,4'-bis-hydroxyazobenzene as the main chain was designed and synthesized as a pivotal functional *** sufficiently large structural difference under ultraviolet and near-infrared light makes it possible to regulate the viscosity of a polyethylene glycol *** viscosity of the photosensitive rheological fluids under ultraviolet light radiation is found to be up to 45.1%higher than that under near-infrared light *** explore this intelligent lubricating technology,the friction regulation of ceramic sliding bearings was investigated utilizing photosensitive rheological *** friction regulation with a ratio of up to 3.77 has been achieved by the alternative irradiation of near-infrared and ultraviolet light,which can be attributed to the differences in mechanical properties and molecular structures under ultraviolet and near-infrared light according to both simulations and *** photorheological fluids will have promising applications in controllable lubrication,intelligent rheological fluids,and photosensitive dampers.

关键词： photorheological fluids viscosity azobenzene polymer lubrication

PHOTOINDUCED BIREFRINGENCE AND NUMERICAL SOLUTION OF A NEW DYNAMIC MODEL IN AN AMORPHOUS COpolymer CONTAINING azobenzene GROUPS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2001年第3期19卷 255-263页

作者： Valerica Ninulescu State Key Laboratory of Ultrafast Laser Spectroscopy Guangzhou 510275 China "Politehnica" University of Bucharest Physics Department Romania

Photoinduced birefringence is investigated in a new amorphous copolymer containing azobenzene groups. The levels of birefringence signal are found to depend an the polarization angle between the pump beam and the probe beam, and on the ellipticity of the pump beam. Both the growth and decay processes of the birefringence signal can be described by known biexponential equations. The rate constants and the amplitudes associated with the growth process of the photoinduced birefringence are observed to display a linear dependence with the pump beam intensity. A new dynamic model of the photoinduced birefringence is presented taking into account the contributions of both the bans and cis isomers of azobenzene groups and the local polymer segments. The numerical treatment of this model shows good agreement with the experimental data in the whole writing-erasing processes of the photoinduced birefringence conducted in our polymer samples.

关键词： photoinduced birefringence azobenzene polymer dynamic process numerical simulation

Coherent Random Lasing Realized in polymer Vesicles

在线全文

学校读者我要写书评

暂无评论

Photonic Sensors 2020年第3期10卷 254-264页

作者： Yaxin LI Kang XIE Xiaojuan ZHANG Zhijia HU Jiajun MA Xianxian CHEN Junxi ZHANG Zhenming LIU Dong CHEN Laboratory of Optical Fibers and Micro-nano Photonics School of Instrument Science and Opto-electronics EngineeringHefei University of TechnologyHefei 230009China State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang 621000China Aston Institute of Photonic Technologies Aston UniversityBirmingham B47ETUnited Kingdom Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai UniversityShanghai 200072China Department of Hepatobiliary and Vascular Surgery Huangshan People’s HospitalHuangshan 245000China

We have demonstrated the realization of a coherent vesicle random lasing(VRL)from the dye doped azobenzene polymer vesicles self-assembled in the tetrahydrofuran-water system,which contains a double-walled structure:a hydrophilic and hydrophobic *** effect of the dye and azobenzene polymer concentration on the threshold of random laser has been *** threshold of random laser decreases with an increase in the concentration of the pyrromethene 597(PM597)laser and azobenzene ***,the scattering of small size group vesicles is attributed to providing a loop to boost the coherent random laser through the Fourier transform *** to the vesicles having the similar structure with the cell,the generation of coherent random lasers from vesicles expand random lasers to the biomedicine filed.

关键词： Random laser vesicles scattering azobenzene polymer