Two azobenzene compounds,Disperse Red 1(DR1)and 4-aminoazobenzene(Aazo),were separately linked to poly(acrylic acid)(PAA)side chains to form PAA-DR1 and PAA-Aazo,which were then associated with poly(ethylene oxide)(PE...Two azobenzene compounds,Disperse Red 1(DR1)and 4-aminoazobenzene(Aazo),were separately linked to poly(acrylic acid)(PAA)side chains to form PAA-DR1 and PAA-Aazo,which were then associated with poly(ethylene oxide)(PEO)to produce hydrogen-bonded polymer complex fibers.After UV irradiation,the initial modulus and yielding strength of PAA-Aazo/PEO fiber were both increased tremendously,while the mechanical properties of PAA-DR1/PEO fiber only slightly changed.After drawn and dried in vacuum,PAA-DR1/PEO and PAA-Aazo/PEO fibers with an extended length exhibited a contraction of 20%and 25%under UV irradiation,showing potential for photo-actuation.展开更多
Photo-responsive room-temperature phosphorescent(RTP)materials have garnered significant interest due to the advantages of rapid response,spatiotemporal control,and contactless precision manipulation.However,the devel...Photo-responsive room-temperature phosphorescent(RTP)materials have garnered significant interest due to the advantages of rapid response,spatiotemporal control,and contactless precision manipulation.However,the development of such materials remains in its infancy,underscoring the importance of exploiting novel and efficient light-responsive RTP molecules.In this work,three phenothiazine derivatives of TPA-PTZ,TPA-2PTZ,and TPA-3PTZ were successfully synthesized via the Buchwald-Hartwig C—N coupling reaction.By embedding these molecules as RTP guests into polymethyl methacrylate(PMMA)matrix,photo-induced RTP properties were realized.Upon sustained UV irradiation,there was an enhancement of 19 times in the quantum yield to reach a value of 5.68%.Remarkably,these materials exhibit superior alongside robust light and thermal stability,maintaining high phosphorescence intensity even after prolonged UV exposure(irradiation for>200 s by a 365 nm UV lamp with the power of 500μW·cm-2)or at higher temperature up to 75℃.The outstanding properties of these photo-induced RTP materials make them promising candidates for applications in information encryption,anti-counterfeiting,and advanced optical materials.展开更多
The photo-dimerization characteristics of coumarin pendants within amphiphilic random copolymer micelles in aqueous solution was comprehensively investigated using various selected wavelength light in the UV-Vis-NIR r...The photo-dimerization characteristics of coumarin pendants within amphiphilic random copolymer micelles in aqueous solution was comprehensively investigated using various selected wavelength light in the UV-Vis-NIR region. The time-dependent photo-dimerization degree （PD） changes in the photo-dimerization experiments showed saturating behaviors with intensity-independent of PDmax values at 28%, 44%, 92%, 85%, 36%, 35%, 32% and 31% for 254, 288, 320, 360, 400, 500, 650 and 900 nm irradiations, respectively. The irradiation experiments at 254 and 288 nm announced the occurring of an asymmetric equilibrium of photo-dimerization and photo-cleavage at the used conditions. Both the alternative irradiation cycles of 360 and 254 nm, 650 and 254 nm showed a partially, but evidently reversible photo-dimerization tendency.展开更多
A one-step process to introduce both the aromatic and aliphatic primary amino groups with high chemoselectivity was developed. Triplet state acetone abstracts the hydrogen atoms from both the C--H bond of the polymeri...A one-step process to introduce both the aromatic and aliphatic primary amino groups with high chemoselectivity was developed. Triplet state acetone abstracts the hydrogen atoms from both the C--H bond of the polymeric film substrate and the O--H bond of phenol which is the building block and the amino group carrier. As a result, two kinds of free radicals, confined carbon-centered chain radicals of the polymer substrate and mobile oxygen-centered phenoxy radicals, were generated. Then the C--O bonds were formed by the coupling reaction between these two kinds of free radicals, p-Tyrarnine and p-aminophenol were used as amino carriers. The successful introduction of amino groups onto LDPE, BOPP and PET film substrates was demonstrated by measurements of water contract angle （CA）, ultraviolet spectra （UV）, X-ray photoelectron spectroscopy （XPS） and fluorescent microscopy. The processing factors, such as the UV-light intensity and irradiation time, concentrations of p-tyramine and p-aminophenol, and the ratio of acetone/water were investigated. The optimized process parameters are as follows： UV light intensity 9500 ~tW/cm2; irradiation time 18 min for BOPP and LDPE, 22 min for PET; the ratio of acetone/water = 1; and concentration ofp-tyramine and p-aminophenol 15% for BOPP and LDPE, 1% for PET. Based on the UV absorbance, the amino groups on the polymeric substrates were estimated to be in the range of 6.3 × 10-6-9.5 × 10-6 mmol/mm2.展开更多
Poly(lactic acid)(PLA)is one of the most important bio-plastics,and chemical modification of the already-polymerized poly(lactic acid)chains may enable optimization of its material properties and expand its applicatio...Poly(lactic acid)(PLA)is one of the most important bio-plastics,and chemical modification of the already-polymerized poly(lactic acid)chains may enable optimization of its material properties and expand its application areas.In this study,we demonstrated that poly(lactic acid)can be readily dissolved in acrylic acid at room temperature,and acrylic acid can be graft-polymerized onto poly(lactic acid)chains in solution with the help of photoinitiator benzophenone under 254 nm ultraviolet(UV)irradiation.Similar photo-grafting polymerization of acrylic acid(PAA)has only been studied before in the surface modification of polymer films.The graft ratio could be controlled by various reaction parameters,including irradiation time,benzophenone content,and monomer/polymer ratios.This photo-grafting reaction resulted in high graft ratio(graft ratio PAA/PLA up to 180%)without formation of homopolymers of acrylic acid.When the PAA/PLA graft ratio was higher than 100%,the resulting PLA-g-PAA polymer was found dispersible in water.The pros and cons of the photo-grafting reaction were also discussed.展开更多
A preliminary investigation on short-wavelength ablation mechanisms of poly(methyl methacrylate)(PMMA) and poly(1,4-phenylene ether ether-sulfone)(PPEES) by extreme ultraviolet(EUV) radiation at 13.5 nm using a table-...A preliminary investigation on short-wavelength ablation mechanisms of poly(methyl methacrylate)(PMMA) and poly(1,4-phenylene ether ether-sulfone)(PPEES) by extreme ultraviolet(EUV) radiation at 13.5 nm using a table-top laserproduced plasma from a gas-puff target at LLG(Gttingen) and at 46.9 nm by a 10 Hz desktop capillary discharge laser operated at the Institute of Physics(Prague) is presented.Ablation of polymer materials is initiated by photoinduced polymer chain scissions.The ablation occurs due to the formation of volatile products by the EUV radiolysis removed as an ablation plume from the irradiated material into the vacuum.In general,cross-linking of polymer molecules can compete with the chain decomposition.Both processes may influence the efficiency and quality of micro(nano)structuring in polymer materials.Wavelength is a critical parameter to be taken into account when an EUV ablation process occurs,because different wavelengths result in different energy densities in the near-surface region of the polymer exposed to nanosecond pulses of intense EUV radiation.展开更多
A new type of photo-induced supramolecular polymer was fabricated by host-guest interaction from a phototrigger containing building block. A dibenzo-24-crown-8 （DB24C8） macrocycle and dibenzylammonium （DBA） site c...A new type of photo-induced supramolecular polymer was fabricated by host-guest interaction from a phototrigger containing building block. A dibenzo-24-crown-8 （DB24C8） macrocycle and dibenzylammonium （DBA） site containing linear monomer was designed and synthesized. The coumarin, as a photocleavable protector, was introduced to the terminal of the monomer. When exposed to the UV light, the coumarin unit would be cleavaged and the monomer without terminal coumarin can self-assemble into supramolecular polymers via the host-guest interaction between DB24C8 moieties and DBA units. Increasing the concentration of the monomer, the supramolecular polymers will convert to supramolecular organogel by cross-linking with each other.展开更多
In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorp...In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization （LPP） method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal （LC） cells containing nematic liquid crystal （5CB）. The observation by polarized microscope showed that the H30-Ci blended with a linear polymer （BP-AN-Ci） photo-alignment layers could align LC molecules in a very uniform way.展开更多
The preparation of a nonlinear directional coupler in polymer PMMA/DR1 film by photobleaching is studied. We find it easier to obtain a required coupling length by controlling photo bleaching time than by controlling ...The preparation of a nonlinear directional coupler in polymer PMMA/DR1 film by photobleaching is studied. We find it easier to obtain a required coupling length by controlling photo bleaching time than by controlling the dimension of the coupler. The transmittance of each arm is measured when the pulse input light energy changes in our experiment. The experimental results show that the coupling length will change with the intensity of input light due to optical nonlinearities of the polymer PMMA/DR1 at 1 064 nm.展开更多
Device stability becomes one of the most crucial issues for the commercialization of organic solar cells(OSCs) after high power conversion efficiencies have been achieved. Besides the intrinsic stability of photoactiv...Device stability becomes one of the most crucial issues for the commercialization of organic solar cells(OSCs) after high power conversion efficiencies have been achieved. Besides the intrinsic stability of photoactive materials, the chemical/catalytic reaction between interfacial materials and photoactive materials is another critical factor that determines the stability of OSC devices. Herein, we design and synthesize a reaction-inert rylene diimide-embedded hyperbranched polymer named as PDIEIE, which effectively reduces the work function of indium tin oxide electrode from 4.62 to 3.65 eV. Meanwhile, PDIEIE shows negligible chemical reaction with high-performance photoactive materials and no catalytic effect under strong ultraviolet illumination, resulting in much better photo-stability of OSCs with PDIEIE cathode interlayer(CIL), relative to the traditional CILs, including most-widely used metal oxides and polyethyleneimine derivatives.展开更多
On-demand regulation of molecular weight distribution(MWD)is crucial to influence the properties of polymers.In this work,we reported an organocatalyzed photo-controlled radical polymerization(photo-CRP)from the tosyl...On-demand regulation of molecular weight distribution(MWD)is crucial to influence the properties of polymers.In this work,we reported an organocatalyzed photo-controlled radical polymerization(photo-CRP)from the tosyl chloride initiator by combining two disulfides as chain transfer agents.This novel synthetic protocol allows facile access toward well-defined polymers with tunable MWDs and predetermined molecular weights.Experiments including structural characterization,kinetic investigation and chain-extension polymerization exhibited good chain-growth control for polymers of different dispersities.Given the easy accessibility of the initiating site(sulfonyl chloride)on many aromatic sources,this work presents a promising avenue to modify such substances with polymers of tailored MWDs,chain lengths and repeating units under metal-free and mild conditions driven by light.展开更多
基金National Natural Science Foundation of China(No.51973029)Science and Technology Commission of Shanghai Municipality(No.20JC1414900).
文摘Two azobenzene compounds,Disperse Red 1(DR1)and 4-aminoazobenzene(Aazo),were separately linked to poly(acrylic acid)(PAA)side chains to form PAA-DR1 and PAA-Aazo,which were then associated with poly(ethylene oxide)(PEO)to produce hydrogen-bonded polymer complex fibers.After UV irradiation,the initial modulus and yielding strength of PAA-Aazo/PEO fiber were both increased tremendously,while the mechanical properties of PAA-DR1/PEO fiber only slightly changed.After drawn and dried in vacuum,PAA-DR1/PEO and PAA-Aazo/PEO fibers with an extended length exhibited a contraction of 20%and 25%under UV irradiation,showing potential for photo-actuation.
文摘Photo-responsive room-temperature phosphorescent(RTP)materials have garnered significant interest due to the advantages of rapid response,spatiotemporal control,and contactless precision manipulation.However,the development of such materials remains in its infancy,underscoring the importance of exploiting novel and efficient light-responsive RTP molecules.In this work,three phenothiazine derivatives of TPA-PTZ,TPA-2PTZ,and TPA-3PTZ were successfully synthesized via the Buchwald-Hartwig C—N coupling reaction.By embedding these molecules as RTP guests into polymethyl methacrylate(PMMA)matrix,photo-induced RTP properties were realized.Upon sustained UV irradiation,there was an enhancement of 19 times in the quantum yield to reach a value of 5.68%.Remarkably,these materials exhibit superior alongside robust light and thermal stability,maintaining high phosphorescence intensity even after prolonged UV exposure(irradiation for>200 s by a 365 nm UV lamp with the power of 500μW·cm-2)or at higher temperature up to 75℃.The outstanding properties of these photo-induced RTP materials make them promising candidates for applications in information encryption,anti-counterfeiting,and advanced optical materials.
基金financially supported by the National Natural Science Foundation of China(No.21374056)the Natural Science Basic Research Plan in Shaanxi Province of China(NSBRP-SPC 2014JM2051)+2 种基金the Fundamental Research Funds for the Central Universities(GK201302045)Shaanxi Innovative Research Team for Key Science and Technology(2012KCT-21,2013KCT-17)the One Hundred Plan of Shaanxi Province
文摘The photo-dimerization characteristics of coumarin pendants within amphiphilic random copolymer micelles in aqueous solution was comprehensively investigated using various selected wavelength light in the UV-Vis-NIR region. The time-dependent photo-dimerization degree （PD） changes in the photo-dimerization experiments showed saturating behaviors with intensity-independent of PDmax values at 28%, 44%, 92%, 85%, 36%, 35%, 32% and 31% for 254, 288, 320, 360, 400, 500, 650 and 900 nm irradiations, respectively. The irradiation experiments at 254 and 288 nm announced the occurring of an asymmetric equilibrium of photo-dimerization and photo-cleavage at the used conditions. Both the alternative irradiation cycles of 360 and 254 nm, 650 and 254 nm showed a partially, but evidently reversible photo-dimerization tendency.
基金financially supported by Chinese Universities Scientific Fund(No.ZD0902)the National High Technology Research and Development Program(No.863 Program 2009AA03Z325)
文摘A one-step process to introduce both the aromatic and aliphatic primary amino groups with high chemoselectivity was developed. Triplet state acetone abstracts the hydrogen atoms from both the C--H bond of the polymeric film substrate and the O--H bond of phenol which is the building block and the amino group carrier. As a result, two kinds of free radicals, confined carbon-centered chain radicals of the polymer substrate and mobile oxygen-centered phenoxy radicals, were generated. Then the C--O bonds were formed by the coupling reaction between these two kinds of free radicals, p-Tyrarnine and p-aminophenol were used as amino carriers. The successful introduction of amino groups onto LDPE, BOPP and PET film substrates was demonstrated by measurements of water contract angle （CA）, ultraviolet spectra （UV）, X-ray photoelectron spectroscopy （XPS） and fluorescent microscopy. The processing factors, such as the UV-light intensity and irradiation time, concentrations of p-tyramine and p-aminophenol, and the ratio of acetone/water were investigated. The optimized process parameters are as follows： UV light intensity 9500 ~tW/cm2; irradiation time 18 min for BOPP and LDPE, 22 min for PET; the ratio of acetone/water = 1; and concentration ofp-tyramine and p-aminophenol 15% for BOPP and LDPE, 1% for PET. Based on the UV absorbance, the amino groups on the polymeric substrates were estimated to be in the range of 6.3 × 10-6-9.5 × 10-6 mmol/mm2.
基金financially supported by the National Natural Science Foundation of China (No. 21434008)
文摘Poly(lactic acid)(PLA)is one of the most important bio-plastics,and chemical modification of the already-polymerized poly(lactic acid)chains may enable optimization of its material properties and expand its application areas.In this study,we demonstrated that poly(lactic acid)can be readily dissolved in acrylic acid at room temperature,and acrylic acid can be graft-polymerized onto poly(lactic acid)chains in solution with the help of photoinitiator benzophenone under 254 nm ultraviolet(UV)irradiation.Similar photo-grafting polymerization of acrylic acid(PAA)has only been studied before in the surface modification of polymer films.The graft ratio could be controlled by various reaction parameters,including irradiation time,benzophenone content,and monomer/polymer ratios.This photo-grafting reaction resulted in high graft ratio(graft ratio PAA/PLA up to 180%)without formation of homopolymers of acrylic acid.When the PAA/PLA graft ratio was higher than 100%,the resulting PLA-g-PAA polymer was found dispersible in water.The pros and cons of the photo-grafting reaction were also discussed.
基金the support of the Ministry of Education,Youth and Sports to the HiLASE (CZ.1.05/2.1.00/01.0027)DPSSLasers (CZ.1.07/2.3.00/20.0143) projects+5 种基金co-financed from the European Regional Development-Fundsupported by the grant RVO 68407700financial support by the ‘Deutsche Forschungs-gemeinschaft’ within the Sonderforschungsbereich 755 ‘Nanoscale Photonic Imaging’the Czech Science Foundation (14-29772S)from EU COST MPO1203from the Ministry of Education,Youth and Sports,COST CZ VES14 LD14032 are also appreciated
文摘A preliminary investigation on short-wavelength ablation mechanisms of poly(methyl methacrylate)(PMMA) and poly(1,4-phenylene ether ether-sulfone)(PPEES) by extreme ultraviolet(EUV) radiation at 13.5 nm using a table-top laserproduced plasma from a gas-puff target at LLG(Gttingen) and at 46.9 nm by a 10 Hz desktop capillary discharge laser operated at the Institute of Physics(Prague) is presented.Ablation of polymer materials is initiated by photoinduced polymer chain scissions.The ablation occurs due to the formation of volatile products by the EUV radiolysis removed as an ablation plume from the irradiated material into the vacuum.In general,cross-linking of polymer molecules can compete with the chain decomposition.Both processes may influence the efficiency and quality of micro(nano)structuring in polymer materials.Wavelength is a critical parameter to be taken into account when an EUV ablation process occurs,because different wavelengths result in different energy densities in the near-surface region of the polymer exposed to nanosecond pulses of intense EUV radiation.
基金support of the National Natural Science Foundation of China (No. 21672060)the Fundamental Research Funds for the Central Universities (Nos. WJ1616011, WJ1213007, 222201717003)the Programme of Introducing Talents of Discipline to Universities(No. B16017)
文摘A new type of photo-induced supramolecular polymer was fabricated by host-guest interaction from a phototrigger containing building block. A dibenzo-24-crown-8 （DB24C8） macrocycle and dibenzylammonium （DBA） site containing linear monomer was designed and synthesized. The coumarin, as a photocleavable protector, was introduced to the terminal of the monomer. When exposed to the UV light, the coumarin unit would be cleavaged and the monomer without terminal coumarin can self-assemble into supramolecular polymers via the host-guest interaction between DB24C8 moieties and DBA units. Increasing the concentration of the monomer, the supramolecular polymers will convert to supramolecular organogel by cross-linking with each other.
基金the National Natural Science Foundation of China (No. 50103005)Thanks for Professor Shi Wenfang of University of Science and Technology of China to supply the hyperbranched polymer(H30).
文摘In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization （LPP） method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal （LC） cells containing nematic liquid crystal （5CB）. The observation by polarized microscope showed that the H30-Ci blended with a linear polymer （BP-AN-Ci） photo-alignment layers could align LC molecules in a very uniform way.
文摘The preparation of a nonlinear directional coupler in polymer PMMA/DR1 film by photobleaching is studied. We find it easier to obtain a required coupling length by controlling photo bleaching time than by controlling the dimension of the coupler. The transmittance of each arm is measured when the pulse input light energy changes in our experiment. The experimental results show that the coupling length will change with the intensity of input light due to optical nonlinearities of the polymer PMMA/DR1 at 1 064 nm.
基金supported by the National Natural Science Foundation of China(52173189 and 22105208)。
文摘Device stability becomes one of the most crucial issues for the commercialization of organic solar cells(OSCs) after high power conversion efficiencies have been achieved. Besides the intrinsic stability of photoactive materials, the chemical/catalytic reaction between interfacial materials and photoactive materials is another critical factor that determines the stability of OSC devices. Herein, we design and synthesize a reaction-inert rylene diimide-embedded hyperbranched polymer named as PDIEIE, which effectively reduces the work function of indium tin oxide electrode from 4.62 to 3.65 eV. Meanwhile, PDIEIE shows negligible chemical reaction with high-performance photoactive materials and no catalytic effect under strong ultraviolet illumination, resulting in much better photo-stability of OSCs with PDIEIE cathode interlayer(CIL), relative to the traditional CILs, including most-widely used metal oxides and polyethyleneimine derivatives.
基金This work was supported by the National Natural Science Foundation of China(No.22171051)the Shanghai Pilot Program for Basic Research-Fudan University 21TQ1400100,China(No.21TQ007)the Project of the State Key Laboratory of Molecular Engineering of Polymers,Fudan University,China。
文摘On-demand regulation of molecular weight distribution(MWD)is crucial to influence the properties of polymers.In this work,we reported an organocatalyzed photo-controlled radical polymerization(photo-CRP)from the tosyl chloride initiator by combining two disulfides as chain transfer agents.This novel synthetic protocol allows facile access toward well-defined polymers with tunable MWDs and predetermined molecular weights.Experiments including structural characterization,kinetic investigation and chain-extension polymerization exhibited good chain-growth control for polymers of different dispersities.Given the easy accessibility of the initiating site(sulfonyl chloride)on many aromatic sources,this work presents a promising avenue to modify such substances with polymers of tailored MWDs,chain lengths and repeating units under metal-free and mild conditions driven by light.
