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Partial pore blockage and polymer chain rigidification phenomena in PEO/ZIF-8 mixed matrix membranes synthesized by in situ polymerization
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作者 Xiaoli Ding Xu Li +4 位作者 Hongyong Zhao Ran Wang Runqing Zhao Hong Li Yuzhong Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第3期501-508,共8页
Nanostructured zeolitic imidazolate frameworks(ZIF-8) was incorporated into the mixture of poly(ethylene glycol) methyl ether acrylate(PEGMEA) and pentaerythritol triacrylate(PETA) to synthesize mixed matrix membranes... Nanostructured zeolitic imidazolate frameworks(ZIF-8) was incorporated into the mixture of poly(ethylene glycol) methyl ether acrylate(PEGMEA) and pentaerythritol triacrylate(PETA) to synthesize mixed matrix membranes(MMMs) by in situ polymerization for CO_2/CH_4 separation. The solvent-free polymerization between PEGMEA and PETA was induced by UV light with 1-hydroxylcyclohexyl phenyl ketone as initiator. The chemical structural characterization was performed by Fourier transform infrared spectroscopy. The morphology was characterized by scanning electron microscope. The average chain-to-chain distance of the polymer chains in MMMs was investigated by X-ray diffraction. The thermal property was evaluated by differential scanning calorimetry. The CH_4 and CO_2 gas transport properties of MMMs are reported. The relationship between gas permeation–separation performances or physical properties and ZIF-8 loading is also discussed. However, the permeation–separation performance was not improved in Robeson upper bound plot compared with original polymer membrane as predicted. The significant partial pore blockage and polymer rigidification effect around the ZIFs confirmed by the increase in glass temperature and the decrease in the d-spacing, were mainly responsible for the failure in performance improvement, which offset the high diffusion induced by porous ZIF-8. 展开更多
关键词 Mixed matrix membrane Partial pore blockage Polymer chain rigidification co2 separation
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Synthesis of poly (vinyl acetate) oligomersand their phase behavior in supercritical carbon dioxide
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作者 Jiao Zhen Song Junying +2 位作者 Fan Wenjing Wang Xiudong Wang Ziyi 《Journal of Southeast University(English Edition)》 EI CAS 2019年第2期264-268,共5页
Three poly(vinyl acetate)(PVAc)oligomers with controlled molecular weight and narrow molecular distribution are synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization.The effects of the re... Three poly(vinyl acetate)(PVAc)oligomers with controlled molecular weight and narrow molecular distribution are synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization.The effects of the reaction temperature and the added amount of initiator of the PVAc polymerization are discussed.In addition,the phase behavior of the prepared PVAc in pressured CO2 is determined via the cloud point method.The results indicate that the cloud point of PVAc increases with the increase in the molecular weight,the PVAc concentration,and the temperature.The cloud point pressures for the PVAc mass concentration of 0.12%with the molecular weight of 1 550,2 120,and 2 960 g/mol are 13.48,13.83 and 15.43 MPa,respectively,at the temperature of 35℃.It reveals that the solubility of PVAc in ScCO2 at relatively low pressure is remarkably limited. 展开更多
关键词 poly(vinyl acetate) polymerization supercritical carbon dioxide cloud point pressure co2-philic polymer
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Manipulation of polymer foam structure based on CO_2-induced changes in polymer fundamental properties 被引量:1
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作者 Tao Liu Dachao Li Ling Zhao Weikang Yuan 《Particuology》 SCIE EI CAS CSCD 2010年第6期607-612,共6页
Foaming of polymers with CO2 has attracted increasing attention in polymer processing studies. Some of the fundamental properties of polymer/CO2 systems is discussed in this short review, including solubility and diff... Foaming of polymers with CO2 has attracted increasing attention in polymer processing studies. Some of the fundamental properties of polymer/CO2 systems is discussed in this short review, including solubility and diffusivity of CO2 in the polymer, polymer crystallization, interfacial tension between the polymer and the gas, and rheology of the CO2/polymers melt. These properties understandably affect the foaming process, and the structures of the foam products. Meanwhile, these properties can be changed via manipulation of CO2 in polymer. The proposed idea is to manipulate the foaming process and the foam structure by CO2-induced changes in these properties. Two cases from the authors' laboratory are presented for elucidating how to use the changes to manipulate the foaming process. 展开更多
关键词 co2 Polymer fundamental properties Foaming Manipulation
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CO_2-responsive Polymeric Fluorescent Sensor with Ultrafast Response
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作者 Yun Wang Meng Huo +6 位作者 Min Zeng Lei Liu Qi-Quan Ye Xi Chen Dan Li Liao Peng Jin-Ying Yuan 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2018年第12期1321-1327,共7页
Response speed is one of the most important evaluation criteria for CO2 sensors. In this work, we report an ultrafast CO2 fluorescent sensor based on poly[oligo(ethylene glycol) methyl ether methacrylate]-b-poly[N,N... Response speed is one of the most important evaluation criteria for CO2 sensors. In this work, we report an ultrafast CO2 fluorescent sensor based on poly[oligo(ethylene glycol) methyl ether methacrylate]-b-poly[N,N-diethylaminoethyl methacrylate-r-4-(2- methylacryloyloxyethylamino)-7-nitro-2,1,3-benzoxadiazole] [POEGMA-b-P(DEAEMA-r-NBDMA)], in which DEAEMA units act as the CO2-responsive segment and 4-nitrobenzo-2-oxa-l,3-diazole (NBD) is the chromophore. The micelles composed of this copolymer could disassemble in 2 s upon CO2 bubbling, accompanying with enhanced fluorescence emission with bathochromic shift. Furthermore, the quantum yield of the NBD chromophore increases with both the CO2 aeration time and the NBD content. Thus we attribute the fluorescent enhancement to the inhibition of the photo-induced electron transfer between unprotonated tertiary amine groups and NBD fluorophores. The sensor is durable although it is based on "soft" materials. These micellar sensors could be facilely recycled by alternative CO2/Ar purging for at least 5 times, indicating good reversibility. 展开更多
关键词 co2-responsive polymer Fluorescent sensor Ultrafast response
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