A novel supramolecular graft copolymer （SGP） composed of viologen-containing copolymer （P（DMA-co- diEV）） as the main chain and Np ended PNIPAM （Np-PNIPAm） as the grafts is prepared （DMA： N,N- dimethylacryami...A novel supramolecular graft copolymer （SGP） composed of viologen-containing copolymer （P（DMA-co- diEV）） as the main chain and Np ended PNIPAM （Np-PNIPAm） as the grafts is prepared （DMA： N,N- dimethylacryamide, diEV： ethylviologen dimer, Np： naphthalene, PNIPAM： poly（N-isopropylacrylamide））. The grafting is based on the triple complexation among a host of cucurbit[8]uril （CB[8]） and two vips of diEV and Np, which is characterized by UV-vis spectra and ITC. Temperature sensitive property of PNIPAm moiety allows SGP to self-assemble into non-covalently connected micelle （NCCM） at high temperature. The micelles are sensitive to reducing agents, for example Na2S203, which breaks the current inclusion complex pair and induces aggregation.展开更多
Research and development of novel fluorine‐free materials to replace fluorinated aqueous film‐forming foam(AFFF)are crucial for improving pool fire suppression performance and protecting the environment.In this stud...Research and development of novel fluorine‐free materials to replace fluorinated aqueous film‐forming foam(AFFF)are crucial for improving pool fire suppression performance and protecting the environment.In this study,we report the thermo‐responsive fluorine‐free foam stabilized by triblock PEO–PPO–PEO copolymers(EO)_(100)(PO)_(65)(EO)_(100)for pool fire suppression.Small‐angle X‐ray scattering(SAXS)and reflected light interferometric techniques are conducted to study the molecular self‐assembly in bulk and film thinning behavior,and the foaming kinetics of copolymer solution and thermophysical properties of the liquid foam are studied by dynamic surface tension and oscillatory rheology analysis.At room temperature,the amphipathic structure of PEO–PPO–PEO makes it possible to absorb at the air–liquid interface forming large‐scale liquid foams containing the mobile films with a detergent state.Upon heating to the surface cooling temperature of burning oil,the mobile films can be actively switched into mechanically strong films with rigid surfaces.The in situ switching of the two interfacial states leads to the significant enhancement of the foam stability,especially under the dual defoaming effects of heat and oil.What's more,it is observed that the confinement of organized copolymer micelles in the Plateau borders and micellar self‐layering in film confinement induce drainage delay of foam and film's stepwise thinning phenomenon,further increasing film thickness and enhancing the thermal stability of the foam.In standard fire‐fighting tests,it is proved that the burnback performance exhibited by thermo‐responsive copolymer foams is three times better than that for classical fluorine‐free foams and almost 1.5 times higher than that for commercial AFFF.展开更多
The increasing development of biomedicine and bioelectronics has highlighted the requirement for smart materials that can respond to changes in physical and chemical properties under external environments,such as magn...The increasing development of biomedicine and bioelectronics has highlighted the requirement for smart materials that can respond to changes in physical and chemical properties under external environments,such as magnetic fields,electric fields,and temperature.Accordingly,hydrogels have been widely evaluated as promising candidates for smart materials owing to their intriguing structures comprising a cross‐linked network of polymer chains with interstitial spaces filled with solvent water.This feature endows hydrogels with soft and wet characteristics,which not only induce high tissue affinity but also allow the introduction of environmentally responsive nanoparticles to release specific smart properties.Herein,we reviewed novel smart hydrogels that can be applied in biomedicine and bioelectronics,and highlighted and discussed existing challenges in current technologies and research.展开更多
基金Ministry of Science and Technology of China(Nos. 2011CB932503 and 2009CB930402)National Natural Science Foundation of China(No.91227203) are acknowledged for their financial support
文摘A novel supramolecular graft copolymer （SGP） composed of viologen-containing copolymer （P（DMA-co- diEV）） as the main chain and Np ended PNIPAM （Np-PNIPAm） as the grafts is prepared （DMA： N,N- dimethylacryamide, diEV： ethylviologen dimer, Np： naphthalene, PNIPAM： poly（N-isopropylacrylamide））. The grafting is based on the triple complexation among a host of cucurbit[8]uril （CB[8]） and two vips of diEV and Np, which is characterized by UV-vis spectra and ITC. Temperature sensitive property of PNIPAm moiety allows SGP to self-assemble into non-covalently connected micelle （NCCM） at high temperature. The micelles are sensitive to reducing agents, for example Na2S203, which breaks the current inclusion complex pair and induces aggregation.
基金supported by the Basic Research Program of Jiangsu Province(No.BE2020663)the Opening Fund of the State Key Laboratory of Fire Science of the University of Science and Technology of China(No.HZ2022‐KF‐09).
文摘Research and development of novel fluorine‐free materials to replace fluorinated aqueous film‐forming foam(AFFF)are crucial for improving pool fire suppression performance and protecting the environment.In this study,we report the thermo‐responsive fluorine‐free foam stabilized by triblock PEO–PPO–PEO copolymers(EO)_(100)(PO)_(65)(EO)_(100)for pool fire suppression.Small‐angle X‐ray scattering(SAXS)and reflected light interferometric techniques are conducted to study the molecular self‐assembly in bulk and film thinning behavior,and the foaming kinetics of copolymer solution and thermophysical properties of the liquid foam are studied by dynamic surface tension and oscillatory rheology analysis.At room temperature,the amphipathic structure of PEO–PPO–PEO makes it possible to absorb at the air–liquid interface forming large‐scale liquid foams containing the mobile films with a detergent state.Upon heating to the surface cooling temperature of burning oil,the mobile films can be actively switched into mechanically strong films with rigid surfaces.The in situ switching of the two interfacial states leads to the significant enhancement of the foam stability,especially under the dual defoaming effects of heat and oil.What's more,it is observed that the confinement of organized copolymer micelles in the Plateau borders and micellar self‐layering in film confinement induce drainage delay of foam and film's stepwise thinning phenomenon,further increasing film thickness and enhancing the thermal stability of the foam.In standard fire‐fighting tests,it is proved that the burnback performance exhibited by thermo‐responsive copolymer foams is three times better than that for classical fluorine‐free foams and almost 1.5 times higher than that for commercial AFFF.
基金Key‐Area Research and Development Program of Guangdong Province,Grant/Award Number:2019B010941002National Natural Science Foundation of China,Grant/Award Numbers:82072071,51972276+2 种基金Sichuan Key Research and Development Program,Grant/Award Number:22ZDYF2034Shenzhen Funds of the Central Government,Grant/Award Number:2021SZVUP123Fundamental Research Funds for Central Universities,Grant/Award Number:2682020ZT79。
文摘The increasing development of biomedicine and bioelectronics has highlighted the requirement for smart materials that can respond to changes in physical and chemical properties under external environments,such as magnetic fields,electric fields,and temperature.Accordingly,hydrogels have been widely evaluated as promising candidates for smart materials owing to their intriguing structures comprising a cross‐linked network of polymer chains with interstitial spaces filled with solvent water.This feature endows hydrogels with soft and wet characteristics,which not only induce high tissue affinity but also allow the introduction of environmentally responsive nanoparticles to release specific smart properties.Herein,we reviewed novel smart hydrogels that can be applied in biomedicine and bioelectronics,and highlighted and discussed existing challenges in current technologies and research.
