The fabrication of raspberry-like poly（ethylene terephthalate）/polyacrylonitrile（PET/PAN） microspheres by g-ray radiation-induced polymerization of acrylonitrile on micron-sized PET microspheres were first reporte...The fabrication of raspberry-like poly（ethylene terephthalate）/polyacrylonitrile（PET/PAN） microspheres by g-ray radiation-induced polymerization of acrylonitrile on micron-sized PET microspheres were first reported in this work. A PET emulsion was firstly prepared by dispersing a PET solution with 1,1,2,2-tetrachloroethane/phenol mixture as the solvent into an aqueous solution of sodium dodecyl sulfate.Then, PET microspheres were formed by precipitating the PET emulsion droplets from ethanol. The influence of the PET solvent and the weight ratio of ethanol to PET emulsion on the morphology of the PET microspheres had been investigated. After the surface of the prepared PET microspheres was grafted with poly（acrylic acid）, the grafting polymerization of AN also had been successfully initiated by g-ray radiation to form PAN microspheres with a size of about 100 nm on the PET microspheres. This work provides a new method to fabricate micron-sized PET microspheres, and further expands the functionalization of PET and its application fields.展开更多
Well-defined raspberry-like magnetic microbeads （RMMBs） as immunoassay solid carriers were pre- pared by chemicM covalent binding between Fe304 magnetic microspheres and SiO2 nanoparticles. These RMMBs were not as a...Well-defined raspberry-like magnetic microbeads （RMMBs） as immunoassay solid carriers were pre- pared by chemicM covalent binding between Fe304 magnetic microspheres and SiO2 nanoparticles. These RMMBs were not as agglomerative as nano-sized magnetie particles （〈 200 nm）, which was an advangtage for high efficient magnetic separation. When compared to Fe304@SiO2 core-shell magnetic microbeads （CMMBs） with smooth surface, RMMBs exhibited stronger capacity to bind biomolecules. Limit of blank （LOB） and limit of detection （LoD） of HBsAg detection using RMMBs as carriers via chemiluminiscence immunoassay （CLIA） were 0.472 and 1.022 μg/L, respectively, showing a notable improvement compared with CMMBs whose LoB and LoD were 1.017 and 1.988 μg/L, respectively. All these indicated a great potential of RMMBs in immunoassay application.展开更多
Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition,presenting both practical value and fundamental challenges.Through precisely controlled carbonization o...Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition,presenting both practical value and fundamental challenges.Through precisely controlled carbonization of polymer-coated Fe_(3)O_(4)@SiO_(2)assembled units,this work elucidates the phase transition-mediated enhancement of electromagnetic wave absorption properties.Raspberry-like C/Fe_(3)O_(4)@SiO_(2)@DC magnetic microspheres are fabricated through a multi-step process involving bubble-assisted hydrothermal growth,silica coating,phosphonitrile polymerization,resin encapsulation,and controlled carbonization.The controlled carbonization temperature-mediated phase transformation from Fe_(3)O_(4)to Fe_(2)SiO_(4)within the microspheres serves to fine-tune both electromagnetic parameters and impedance matching behavior.The C/Fe_(3)O_(4)@Fe_(2)SiO_(4)@DC microspheres carbonized at 700℃exhibit exceptional electromagnetic wave absorption performance,attributed to:(i)the heterogeneous interfaces between dual-phase components,and(ii)the synergistic dielectric-magnetic loss mechanism.The optimized composite demonstrates exceptional microwave absorption performance,achieving a minimum reflection loss(RLmin)of−17.86 dB and an effective absorption bandwidth(EAB)of 6.03 GHz(11.5–17.5 GHz)at an optimal thickness of 2.2 mm.The synergistic combination of tailored composition,optimized interfaces,and controlled defects enables unprecedented EM wave attenuation,providing a blueprint for high-efficiency broadband electromagnetic wave absorbing materials.展开更多
基金the National Natural Science Foundation of China (Nos. 51573174, 51473172, 51173175, 51073146 and 51103143)Foshan Scientific and Technological Innovation Team Project (No. 2013IT100041)the Fundamental Research Funds for the Central Universities (Nos. WK2060200012 and WK3450000001)
文摘The fabrication of raspberry-like poly（ethylene terephthalate）/polyacrylonitrile（PET/PAN） microspheres by g-ray radiation-induced polymerization of acrylonitrile on micron-sized PET microspheres were first reported in this work. A PET emulsion was firstly prepared by dispersing a PET solution with 1,1,2,2-tetrachloroethane/phenol mixture as the solvent into an aqueous solution of sodium dodecyl sulfate.Then, PET microspheres were formed by precipitating the PET emulsion droplets from ethanol. The influence of the PET solvent and the weight ratio of ethanol to PET emulsion on the morphology of the PET microspheres had been investigated. After the surface of the prepared PET microspheres was grafted with poly（acrylic acid）, the grafting polymerization of AN also had been successfully initiated by g-ray radiation to form PAN microspheres with a size of about 100 nm on the PET microspheres. This work provides a new method to fabricate micron-sized PET microspheres, and further expands the functionalization of PET and its application fields.
基金the National Natural Science Foundation of China(No.21075082)the National High Technology Research and Development Program(863) of China(No.2012AA020103)+3 种基金the Shanghai Nano Program(No.11nm0505600)the Shanghai Jiao Tong University Funding(No.YG2012ZD03)the 2012 Shanghai Jiao Tong University and University of Michigan Collaborative Research Projects(No.12X120010007)the Shanghai Municipal Education Commission Project(No.14ZZ023)
文摘Well-defined raspberry-like magnetic microbeads （RMMBs） as immunoassay solid carriers were pre- pared by chemicM covalent binding between Fe304 magnetic microspheres and SiO2 nanoparticles. These RMMBs were not as agglomerative as nano-sized magnetie particles （〈 200 nm）, which was an advangtage for high efficient magnetic separation. When compared to Fe304@SiO2 core-shell magnetic microbeads （CMMBs） with smooth surface, RMMBs exhibited stronger capacity to bind biomolecules. Limit of blank （LOB） and limit of detection （LoD） of HBsAg detection using RMMBs as carriers via chemiluminiscence immunoassay （CLIA） were 0.472 and 1.022 μg/L, respectively, showing a notable improvement compared with CMMBs whose LoB and LoD were 1.017 and 1.988 μg/L, respectively. All these indicated a great potential of RMMBs in immunoassay application.
基金supported by the National Natural Science Foundation of China(22375166,22101229)Natural Science Basic Research Program of Shaanxi(2024JC-JCQN-44)。
文摘Achieving optimal electromagnetic properties in composites requires fine-tuning of microstructure and composition,presenting both practical value and fundamental challenges.Through precisely controlled carbonization of polymer-coated Fe_(3)O_(4)@SiO_(2)assembled units,this work elucidates the phase transition-mediated enhancement of electromagnetic wave absorption properties.Raspberry-like C/Fe_(3)O_(4)@SiO_(2)@DC magnetic microspheres are fabricated through a multi-step process involving bubble-assisted hydrothermal growth,silica coating,phosphonitrile polymerization,resin encapsulation,and controlled carbonization.The controlled carbonization temperature-mediated phase transformation from Fe_(3)O_(4)to Fe_(2)SiO_(4)within the microspheres serves to fine-tune both electromagnetic parameters and impedance matching behavior.The C/Fe_(3)O_(4)@Fe_(2)SiO_(4)@DC microspheres carbonized at 700℃exhibit exceptional electromagnetic wave absorption performance,attributed to:(i)the heterogeneous interfaces between dual-phase components,and(ii)the synergistic dielectric-magnetic loss mechanism.The optimized composite demonstrates exceptional microwave absorption performance,achieving a minimum reflection loss(RLmin)of−17.86 dB and an effective absorption bandwidth(EAB)of 6.03 GHz(11.5–17.5 GHz)at an optimal thickness of 2.2 mm.The synergistic combination of tailored composition,optimized interfaces,and controlled defects enables unprecedented EM wave attenuation,providing a blueprint for high-efficiency broadband electromagnetic wave absorbing materials.
