The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results ...The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results show thatthe polymer mixtures are compatible in DMF solution in the absence of urea. The influence of urea addition on the degree ofcompatibility of the polymer mixtures has been studied in terms of the compatibility parameters (△b_m and △[η]_m). It wasfound that the compatibility of the polymer mixtures is decreased with increasing urea addition, passing through a minimumat 0.5 M urea.展开更多
This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications.Conventionally,dopants have utilized europium(Ⅲ)(Eu(Ⅲ))organic complexes due to their hig...This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications.Conventionally,dopants have utilized europium(Ⅲ)(Eu(Ⅲ))organic complexes due to their high compatibility with polymers and strong fluorescence.However,as the common magnetic material Fe_(3)O_(4)can quench their fluorescence,it is hard to synthesize Eu complexdoped magnetic fluorescent materials.To maintain fluorescence in the presence of magnetic parts,in this work,we synthesized Eu-doped magnetic microspheres with multi-layered structure.Firstly,poly-(glycidyl methacrylate)(PGMA)microspheres were prepared as templates and subsequently coated with layers of Fe_(3)O_(4)and SiO_(2).Then,the synthesized Eu(TTA)_(3)(TPPO)_(2)were added into PGMA@Fe_(3)O_(4)@SiO_(2)microspheres in either basic or acidic conditions,and covered them with an extra sol-gel layer of silica at the same time.The microspheres exhibit a core-shell structure with sub-micron dimensions(580 nm)and possess favorable superparamagnetic properties(M_(s)=22.02 A·m^(2)/kg,Mr=1.37 A·m^(2)/kg,H_(c)=0.242 A/m).But the fluorescence of Eu^(3+)are significantly quenched by Fe_(3)O_(4),O-H oscillators,and N-H oscillators.Finally,to exclude the quenching mentioned above,the first pure SiO_(2)shielding layer and the second Eu(TTA)_(3)(TPPO)_(2)-dispersed SiO_(2)layer were coated onto PGMA@Fe_(3)O_(4)microspheres to prevent the energy transfer due to the quenching centers and hold the fluorescence of Eu^(3+).These findings underscore the considerable potential of these microspheres exhibiting rapid magnetic separation and stable fluorescence for bioimaging and biosensing applications.展开更多
The synthesis of hard-core/soft-shell calcium carbonate （CaCO3）/poly（methyl methacrylate） （PMMA） hybrid structured nanoparticles （〈100nm） by an atomized microemulsion polymerization process is reported. The p...The synthesis of hard-core/soft-shell calcium carbonate （CaCO3）/poly（methyl methacrylate） （PMMA） hybrid structured nanoparticles （〈100nm） by an atomized microemulsion polymerization process is reported. The polymer chains were anchored onto the surface of nano-CaCO3 through use of a cou- pling agent, triethoxyvinyl silane （TEVS）. Ammonium persulfate （APS）, sodium dodecyl sulfate （SDS） and n-pentanol were used as the initiator, surfactant and cosurfactant, respectively. The polymeriza- tion mechanism of the core-shell latex particles is discussed. The encapsulation of nano-CaCO3 by PMMA was confirmed using a transmission electron microscope （TEM）. The grafting percentage of the core-shell particles was investigated by thermogravimetric analysis （TGA）. The nano-CaCO3/PMMA core-shell par- ticles were characterized by Fourier transform infrared （FTIR） spectroscopy and differential scanning calorimetry （DSC）. The FTIR results revealed the existence of a strong interaction at the interface of the nano-CaCO3 particle and the PMMA, which implies that the polymer chains were successfully grafted onto the surface of the nano-CaCO3 particles through the link of the coupling agent, In addition, the TGA and DSC results indicated an enhancement of the thermal stability of the core-shell materials compared with that of the pure nano-PMMA, The nano-CaCO3/PMMA particles were blended into a polypropylene （PP） matrix by melt processing. It can also be observed using scanning electron microscopy （SEM） that the PMMA chains grafted onto the CaCO3 nanoparticles interfere with the aggregation of CaCO3 in the polymer matrix （PP matrix） and thus improve the compatibility of the CaCO3 nanoparticles with the PP matrix.展开更多
文摘The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results show thatthe polymer mixtures are compatible in DMF solution in the absence of urea. The influence of urea addition on the degree ofcompatibility of the polymer mixtures has been studied in terms of the compatibility parameters (△b_m and △[η]_m). It wasfound that the compatibility of the polymer mixtures is decreased with increasing urea addition, passing through a minimumat 0.5 M urea.
基金Project supported by the"Leading Goose"R&D Program(2022C01142)of Zhejiang Provincethe National Key R&D Program of China(2022YFB3503700)。
文摘This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications.Conventionally,dopants have utilized europium(Ⅲ)(Eu(Ⅲ))organic complexes due to their high compatibility with polymers and strong fluorescence.However,as the common magnetic material Fe_(3)O_(4)can quench their fluorescence,it is hard to synthesize Eu complexdoped magnetic fluorescent materials.To maintain fluorescence in the presence of magnetic parts,in this work,we synthesized Eu-doped magnetic microspheres with multi-layered structure.Firstly,poly-(glycidyl methacrylate)(PGMA)microspheres were prepared as templates and subsequently coated with layers of Fe_(3)O_(4)and SiO_(2).Then,the synthesized Eu(TTA)_(3)(TPPO)_(2)were added into PGMA@Fe_(3)O_(4)@SiO_(2)microspheres in either basic or acidic conditions,and covered them with an extra sol-gel layer of silica at the same time.The microspheres exhibit a core-shell structure with sub-micron dimensions(580 nm)and possess favorable superparamagnetic properties(M_(s)=22.02 A·m^(2)/kg,Mr=1.37 A·m^(2)/kg,H_(c)=0.242 A/m).But the fluorescence of Eu^(3+)are significantly quenched by Fe_(3)O_(4),O-H oscillators,and N-H oscillators.Finally,to exclude the quenching mentioned above,the first pure SiO_(2)shielding layer and the second Eu(TTA)_(3)(TPPO)_(2)-dispersed SiO_(2)layer were coated onto PGMA@Fe_(3)O_(4)microspheres to prevent the energy transfer due to the quenching centers and hold the fluorescence of Eu^(3+).These findings underscore the considerable potential of these microspheres exhibiting rapid magnetic separation and stable fluorescence for bioimaging and biosensing applications.
基金the University Grants Commission(UGC),New Delhi for providing the financial support[project fileNo:40-10/2011(SR),dated-July 14,2011]to conduct this research
文摘The synthesis of hard-core/soft-shell calcium carbonate （CaCO3）/poly（methyl methacrylate） （PMMA） hybrid structured nanoparticles （〈100nm） by an atomized microemulsion polymerization process is reported. The polymer chains were anchored onto the surface of nano-CaCO3 through use of a cou- pling agent, triethoxyvinyl silane （TEVS）. Ammonium persulfate （APS）, sodium dodecyl sulfate （SDS） and n-pentanol were used as the initiator, surfactant and cosurfactant, respectively. The polymeriza- tion mechanism of the core-shell latex particles is discussed. The encapsulation of nano-CaCO3 by PMMA was confirmed using a transmission electron microscope （TEM）. The grafting percentage of the core-shell particles was investigated by thermogravimetric analysis （TGA）. The nano-CaCO3/PMMA core-shell par- ticles were characterized by Fourier transform infrared （FTIR） spectroscopy and differential scanning calorimetry （DSC）. The FTIR results revealed the existence of a strong interaction at the interface of the nano-CaCO3 particle and the PMMA, which implies that the polymer chains were successfully grafted onto the surface of the nano-CaCO3 particles through the link of the coupling agent, In addition, the TGA and DSC results indicated an enhancement of the thermal stability of the core-shell materials compared with that of the pure nano-PMMA, The nano-CaCO3/PMMA particles were blended into a polypropylene （PP） matrix by melt processing. It can also be observed using scanning electron microscopy （SEM） that the PMMA chains grafted onto the CaCO3 nanoparticles interfere with the aggregation of CaCO3 in the polymer matrix （PP matrix） and thus improve the compatibility of the CaCO3 nanoparticles with the PP matrix.
