Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration （NF） membrane was fabricated by simply dipping polysulfone （PSf） ultraf...Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration （NF） membrane was fabricated by simply dipping polysulfone （PSf） ultrafiltration （UF） substrate in dopamine solution. The changes in surface chemical composition and morphology of membranes were determined by Fourier transform infrared spectroscopy （FTIR-ATR）, X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The experimental results indicated that the self-polymerized dopamine formed an ultrathin and defect-free barrier layer on the PSf UF membrane. The surface hydrophilicity of membranes was evaluated through water contact angle measurements. It was found that membrane hydrophilicity was significantly improved after coating a polydopamine （pDA） layer, especially after double coating. The dyes filtration experiments showed that the double-coated membranes were able to reject completely the dyes of brilliant blue, congo red and methyl orange with a pure water flux of 83.7 L/（mE.h） under 0.6 MPa. The zeta potential determination revealed the positively-charged characteristics of PSf/pDA composite membrane in NF process. The salt rejection of the membranes was characterized by 0.01 mmol/L of salts filtration experiment. It was demonstrated that the salts rejections followed the sequence： NaC1 〈 NaaSO4 〈 MgSO4 〈 MgC12 〈 CaCl2, and the rejection to CaC12 reached 68.7%. Moreover, the composite NF membranes showed a good stability in water-phase filtration process.展开更多
In this work, the polyacrylonitrile containing gadolinium nanofibers for thermal neutron protection were successfully fabricated by electrospunning and followed by in situ self-polymerization. Scanning electron micros...In this work, the polyacrylonitrile containing gadolinium nanofibers for thermal neutron protection were successfully fabricated by electrospunning and followed by in situ self-polymerization. Scanning electron microscopy(SEM) and energy-dispersive spectroscopy(EDS) results show that there are no beads on the smooth surface of the nanofibers and gadolinium elements are uniformly dispersed in the matrix. The thermal analysis and FTIR results prove that gadolinium methacrylate is induced in situ selfpolymerization during the heat treatment. The leaching rate of Gd^(3+) decreases from 79.97% to 10.74% tested by lowfield nuclear magnetic resonance(LF-NMR) method after the self-polymerization of gadolinium methacrylate in the matrix when the nanofibers were immersed in water for7 days. The thermal neutron shielding analysis calculated by MCNP program shows that above 99% thermal neutrons are absorbed when traveling through the 2-mm-thick polyacrylonitrile containing gadolinium nanofibers.展开更多
A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR...A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR） and silicone rubber（SiR） were used as the substrate for Eu（TTA）3 AA to prepare fluorescence composites.The neat Eu（TTA）3 AA complex showed the ability of self-polymerization when it was heated at 145 °C.It was found that the fluorescence intensity of the neat Eu（TTA）3 AA decreased over 70% when the polymerization time was over 25 min at 145 °C.The results also revealed that the polymerizated Eu（TTA）3 AA could be dispersed in nano-scale in two matrices and the luminescent intensities decreased 52% in NBR matrix,and 95% in SiR matrix compared with two relative compounds without crosslinking.To optimize the luminescence intensity of the composites,the Eu（TTA）3 AA polymerization kinetic process in matrix was investigated in detail by controlling the temperature,the crosslinking agent,etc.The results showed that the peroxide could accelerate Eu（TTA）3 AA self-polymerization in the rubber matrix,and therefore improved the dispersion,but not be helpful for the luminescence intensity enhancement.In addition,the relatively higher luminescence intensity in Eu（TTA）3 AA/NBR in comparison to that of Eu（TTA）3 AA/SiR might contribute to the interaction between nitrile group（–CN） in NBR and Eu-complexes,suggesting that the luminescence intensity of the composites also depended on the matrix characteristics.展开更多
基金financially supported by the National Natural Science Foundation of China(No.50803054)Zhejiang Provincial Nature Science Foundation of China(No.Y4100204)
文摘Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration （NF） membrane was fabricated by simply dipping polysulfone （PSf） ultrafiltration （UF） substrate in dopamine solution. The changes in surface chemical composition and morphology of membranes were determined by Fourier transform infrared spectroscopy （FTIR-ATR）, X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The experimental results indicated that the self-polymerized dopamine formed an ultrathin and defect-free barrier layer on the PSf UF membrane. The surface hydrophilicity of membranes was evaluated through water contact angle measurements. It was found that membrane hydrophilicity was significantly improved after coating a polydopamine （pDA） layer, especially after double coating. The dyes filtration experiments showed that the double-coated membranes were able to reject completely the dyes of brilliant blue, congo red and methyl orange with a pure water flux of 83.7 L/（mE.h） under 0.6 MPa. The zeta potential determination revealed the positively-charged characteristics of PSf/pDA composite membrane in NF process. The salt rejection of the membranes was characterized by 0.01 mmol/L of salts filtration experiment. It was demonstrated that the salts rejections followed the sequence： NaC1 〈 NaaSO4 〈 MgSO4 〈 MgC12 〈 CaCl2, and the rejection to CaC12 reached 68.7%. Moreover, the composite NF membranes showed a good stability in water-phase filtration process.
基金financially supported by Postgraduate Research & Practice Innovation Program of Jiangsu Province (No. KYLX_1337)the Excellent Doctorial Dissertations Fund of Yangzhou University
文摘In this work, the polyacrylonitrile containing gadolinium nanofibers for thermal neutron protection were successfully fabricated by electrospunning and followed by in situ self-polymerization. Scanning electron microscopy(SEM) and energy-dispersive spectroscopy(EDS) results show that there are no beads on the smooth surface of the nanofibers and gadolinium elements are uniformly dispersed in the matrix. The thermal analysis and FTIR results prove that gadolinium methacrylate is induced in situ selfpolymerization during the heat treatment. The leaching rate of Gd^(3+) decreases from 79.97% to 10.74% tested by lowfield nuclear magnetic resonance(LF-NMR) method after the self-polymerization of gadolinium methacrylate in the matrix when the nanofibers were immersed in water for7 days. The thermal neutron shielding analysis calculated by MCNP program shows that above 99% thermal neutrons are absorbed when traveling through the 2-mm-thick polyacrylonitrile containing gadolinium nanofibers.
基金Program for Chang Jiang Scholars and Innovative Research Team in University(PCSIRT,IRT0807)National Natural Science Foundation of China(51073008,51103005)the Fundamental Research Funds for the Central Universities in China
文摘A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR） and silicone rubber（SiR） were used as the substrate for Eu（TTA）3 AA to prepare fluorescence composites.The neat Eu（TTA）3 AA complex showed the ability of self-polymerization when it was heated at 145 °C.It was found that the fluorescence intensity of the neat Eu（TTA）3 AA decreased over 70% when the polymerization time was over 25 min at 145 °C.The results also revealed that the polymerizated Eu（TTA）3 AA could be dispersed in nano-scale in two matrices and the luminescent intensities decreased 52% in NBR matrix,and 95% in SiR matrix compared with two relative compounds without crosslinking.To optimize the luminescence intensity of the composites,the Eu（TTA）3 AA polymerization kinetic process in matrix was investigated in detail by controlling the temperature,the crosslinking agent,etc.The results showed that the peroxide could accelerate Eu（TTA）3 AA self-polymerization in the rubber matrix,and therefore improved the dispersion,but not be helpful for the luminescence intensity enhancement.In addition,the relatively higher luminescence intensity in Eu（TTA）3 AA/NBR in comparison to that of Eu（TTA）3 AA/SiR might contribute to the interaction between nitrile group（–CN） in NBR and Eu-complexes,suggesting that the luminescence intensity of the composites also depended on the matrix characteristics.
