Hydrophilic surface modification of poly(phthalazinone ether sulfone ketone)(PPESK) porous membranes was achieved via surface-initiated atom transfer radical polymerization(ATRP) in aqueous medium.Prior to ATRP.chloro...Hydrophilic surface modification of poly(phthalazinone ether sulfone ketone)(PPESK) porous membranes was achieved via surface-initiated atom transfer radical polymerization(ATRP) in aqueous medium.Prior to ATRP.chloromethyl groups were introduced onto PPESK main chains by chloromethylation.Chloromethvlated PPESK(CMPPESK) was fabricated into porous membrane through phase inversion technique.Hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate)(P(PEGMA)) brushes were grafted from CMPPESK membrane ...展开更多
Grafting of polystyrene with narrowly dispersed polymer microspheres through surface-initiated atom transferradical polymerization(ATRP)was investigated.Polydivinylbenzene(PDVB)microspheres were prepared by dispersion...Grafting of polystyrene with narrowly dispersed polymer microspheres through surface-initiated atom transferradical polymerization(ATRP)was investigated.Polydivinylbenzene(PDVB)microspheres were prepared by dispersionpolymerization with poly(N-vinyl pyrrolidone)(PVP)as stabilizer.The surfaces of PDVB microspheres werechloromethylated by chloromethyl methyl ether in the presence of zinc chloride as catalyst to form chloromethylbenzeneinitiating core sites for subsequent ATRP grafting of styrene using CuCl/bpy as catalytic system.Polystyrene was found to begrafted not only from the particle surfaces but also from within a thin shell layer,resulting in the formation of particles sizeincreased from 2.38-2.58 μm,which can further grow to 2.93 μm during secondary grafting polymerization of styrene.Thisdemonstrates that grafting polymerization proceeds through a typical ATRP procedure with living nature.All of the preparedmicrospheres have narrow particle size distribution with coefficient of variation around 10%.展开更多
Poly(glycidyl methacrylates)(PGMA) was grafted from zinc oxide(ZnO) nanowires via surface-initiated atom transfer radical polymerization(SI-ATRP) technique.Firstly,the ZnO nanowires were synthesized by the one-pot hyd...Poly(glycidyl methacrylates)(PGMA) was grafted from zinc oxide(ZnO) nanowires via surface-initiated atom transfer radical polymerization(SI-ATRP) technique.Firstly,the ZnO nanowires were synthesized by the one-pot hydrothermal technique.Subsequently,the ZnO was functionalized with 3-aminopropyl triethoxysilane,which was converted to macroinitiator by the esterification of them with 2-bromopropionyl bromide.PGMA grafted ZnO nanowires(PGMA-ZnO) were then synthesized in an ATRP of the GMA with CuCl/2,2`-bipyridine as the catalyst system.Kinetics studies revealed an approximate linear increase in weight of polymer with reaction time,indicating that the polymerization process owned some "living" character.The structure and composition of PGMA-ZnO were characterized with scanning electron microscope(SEM),energy-dispersive X-ray(EDX) spectrometer,fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA).展开更多
To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers re...To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.展开更多
Poly（glycidylmethacrylate） （PGMA） brushes were grafted from chloromethylated polysulfone （CMPSF） mem- brane surface by surface-initiated atom transfer radical polymerization （S1-ATRP）, and the grafting was fol...Poly（glycidylmethacrylate） （PGMA） brushes were grafted from chloromethylated polysulfone （CMPSF） mem- brane surface by surface-initiated atom transfer radical polymerization （S1-ATRP）, and the grafting was followed by hydrolysis of epoxy groups in the grafting chains to improve the membrane＇s hydrophilie property. Fourier trans- form infrared spectroscopy （FT-IR） and X-ray photoelectron spectroscopy （XPS） measurements confirmed the suc- cessful grafting and hydrolysis of PGMA. The grafting degree of the monomer, measured by periodic acid titration and gravimetric analysis, increased linearly with the polymerization time, while the static water contact angle of the membrane grafted with PGMA or hydrolyzed PGMA linearly decreased. In comparison with the PGMA-grafted membranes, the hydrolyzed PGMA-grafted membranes possess stronger hydrophilicity as indicated by their contact angle and hydration capacity, and as a result they have an improved antifouling property. Therefore, the control of the hydrophilicity of PSF membrane could be realized through adjusting the polymerization time and transforming the functional groups in the grafting chain.展开更多
A one-step procedure to hydrophilize monodisperse poly（chloromethyl-styrene-co-divinylbenzene） beads has been presented with 2-hydroxy-3-[4-（hydroxymethyl）-1H-1,2,3-triazol-1-yl]propy1 2-methylacrylate（HTMA） as ...A one-step procedure to hydrophilize monodisperse poly（chloromethyl-styrene-co-divinylbenzene） beads has been presented with 2-hydroxy-3-[4-（hydroxymethyl）-1H-1,2,3-triazol-1-yl]propy1 2-methylacrylate（HTMA） as monomer by surface-initiated atom transfer radical polymerization（SI-ATRP）.The length of the grafted poly（HTMA） chain was varied via controlling the ratio of HTMA to initiator on the surface of the beads.Using these grafted beads as the stationary phase in hydrophilic interaction chromatography,good separation was obtained for nucleosides in the mobile phase of acetonitrile-water.It was also found that the retention time and selectivity of solutes showed a positive relationship with the length of the grafted poly（HTMA） chain.展开更多
Surface-attached micropattemed polyelectrolyte brushes on planar solid surfaces are generated using free radical polymerization photo-initiated by self-assembled initiator monolayers. It is shown that the formed patte...Surface-attached micropattemed polyelectrolyte brushes on planar solid surfaces are generated using free radical polymerization photo-initiated by self-assembled initiator monolayers. It is shown that the formed patterns can be either negative or positive with different patterning processes.展开更多
The poly (N-isopropylacrylamide) brush was covalently bonded on an initiator-coated silicon wafer via surface-initiated atom transfer radical polymerization. The polymer brush was (76.2±0.1) nm in thickness (by e...The poly (N-isopropylacrylamide) brush was covalently bonded on an initiator-coated silicon wafer via surface-initiated atom transfer radical polymerization. The polymer brush was (76.2±0.1) nm in thickness (by ellipsometer) with a grafting density of ca. 0.27 chains/nm 2 . The tribological properties of the poly (N-isopropylacrylamide) brush were investigated by means of ball-on-disk tests in a rotational mode under water lubrication for tribological application. The experimental results exhibited a low friction coefficient of ca. 0.03. The excellent lubrication property of the brush was due to its amide groups in the polymer chains. It was supposed that the good lubrication property of the brush was attributed to the cross-linked polymer network formed by the hydrogen bond association of N-H…O==C and the water molecular layer adsorbed by the terminal amide groups in the brush. The poly (N-isopropylacrylamide) solution also exhibits a lubrication property due to physical adsorption of the polymer chains.展开更多
Narrow-disperse, surface-functionalized ＂living＂ polymer microspheres with uniformly cross-linked structures were prepared by two-stage precipitation copolymerization of styrene and divinylbenzene. The two-stage pre...Narrow-disperse, surface-functionalized ＂living＂ polymer microspheres with uniformly cross-linked structures were prepared by two-stage precipitation copolymerization of styrene and divinylbenzene. The two-stage precipitation polymerization is composed of an initial conventional precipitation polymerization for the nucleation followed by a reverse atom transfer radical polymerization （reverse ATRP） for the controlled polymerization process. The polymerization parameters （including reaction time for the first stage, AIBN amount and monomer loading） have been studied to show significant influences on the morphologies. Moreover, narrower size distribution and an ATRP initiator-functional surface of resulting particles can be obtained by applying reverse ATRP to conventional precipitation polymerization in the second stage. Furthermore, the ＂livingness＂ of the resulting polymer microspheres was testified by their surface modification of poly[2-（dimethylamino） ethyl methacrylate] （PDMAEMA） brushes via surface-initiated ATRP （SI-ATRP）.展开更多
Polymers grafted from solid surface are being extensively studied with a range of objectives.The most popular living/controlled polymerization used in polymers grafted from solid surfaces is the surface-initiated atom...Polymers grafted from solid surface are being extensively studied with a range of objectives.The most popular living/controlled polymerization used in polymers grafted from solid surfaces is the surface-initiated atom transfer radical polymerization（SI-ATRP）[1,2].An attractive feature of atom transfer radical polymerization（ATRP） is to simultaneously grow chains from multifunctional surface.Thus the grafted polymer with well-defined structures could be designed and controlled.ATRP has proven to be a powerful tool to synthesize homopolymers and copolymers,under easily accessible experimental conditions[3-7].Furthermore it is useful for the functionalization of material surfaces by grafting certain polymers.展开更多
The surface ofpoly（ethylene terephthalate）（PET） films is inert, hydrophobic, and incompatible with blood, which has limited its practical bioapplication. In this case, better biocompatibility could be achieved by ...The surface ofpoly（ethylene terephthalate）（PET） films is inert, hydrophobic, and incompatible with blood, which has limited its practical bioapplication. In this case, better biocompatibility could be achieved by surface modification. In this study, the grafted copolymer of functional methoxypolyethylene glycol（mPEG） derivatives and styrene from the PET surfaces was prepared via surface-initiated atom transfer radical polymerization（SI-ATRP）. The structures, composition, properties and surface morphology of the grafted PET films were characterized by Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS）, contact angle measurements and scanning electronic microscopy（SEM）. The results indicate that the surface of the PET films has been covered by a thick targeted copolymer layer that converted the hydrophobic surface of PET to an amphiphilic surface. The bacte- rial adhesion and cell culture results indicate the copolymer-grafted PET film may possess good biocompatibility.展开更多
基金supported by the National Basic Research Program of China(No2009CB623402)China Postdoctoral Science Foundation(No20080430220)
文摘Hydrophilic surface modification of poly(phthalazinone ether sulfone ketone)(PPESK) porous membranes was achieved via surface-initiated atom transfer radical polymerization(ATRP) in aqueous medium.Prior to ATRP.chloromethyl groups were introduced onto PPESK main chains by chloromethylation.Chloromethvlated PPESK(CMPPESK) was fabricated into porous membrane through phase inversion technique.Hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate)(P(PEGMA)) brushes were grafted from CMPPESK membrane ...
基金This work was supported by the National Natural Science Foundation of China(No.20274018).
文摘Grafting of polystyrene with narrowly dispersed polymer microspheres through surface-initiated atom transferradical polymerization(ATRP)was investigated.Polydivinylbenzene(PDVB)microspheres were prepared by dispersionpolymerization with poly(N-vinyl pyrrolidone)(PVP)as stabilizer.The surfaces of PDVB microspheres werechloromethylated by chloromethyl methyl ether in the presence of zinc chloride as catalyst to form chloromethylbenzeneinitiating core sites for subsequent ATRP grafting of styrene using CuCl/bpy as catalytic system.Polystyrene was found to begrafted not only from the particle surfaces but also from within a thin shell layer,resulting in the formation of particles sizeincreased from 2.38-2.58 μm,which can further grow to 2.93 μm during secondary grafting polymerization of styrene.Thisdemonstrates that grafting polymerization proceeds through a typical ATRP procedure with living nature.All of the preparedmicrospheres have narrow particle size distribution with coefficient of variation around 10%.
基金the National Natural Science Foundation of China (No.50730008 and 30772434)Shanghai Science & Technology Committee (No.09JC1407400 and 1052nm02000)
文摘Poly(glycidyl methacrylates)(PGMA) was grafted from zinc oxide(ZnO) nanowires via surface-initiated atom transfer radical polymerization(SI-ATRP) technique.Firstly,the ZnO nanowires were synthesized by the one-pot hydrothermal technique.Subsequently,the ZnO was functionalized with 3-aminopropyl triethoxysilane,which was converted to macroinitiator by the esterification of them with 2-bromopropionyl bromide.PGMA grafted ZnO nanowires(PGMA-ZnO) were then synthesized in an ATRP of the GMA with CuCl/2,2`-bipyridine as the catalyst system.Kinetics studies revealed an approximate linear increase in weight of polymer with reaction time,indicating that the polymerization process owned some "living" character.The structure and composition of PGMA-ZnO were characterized with scanning electron microscope(SEM),energy-dispersive X-ray(EDX) spectrometer,fourier transform infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA).
基金financially supported by the National Natural Science Foundation of China (No.22263002)the “Overseas 100 Talents Program” of Guangxi Higher Education。
文摘To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.
基金This work was supported by the National Natural Science Foundation of China （No. 20975080） and the key project of Chinese Ministry of Education （No. 212178）.
文摘Poly（glycidylmethacrylate） （PGMA） brushes were grafted from chloromethylated polysulfone （CMPSF） mem- brane surface by surface-initiated atom transfer radical polymerization （S1-ATRP）, and the grafting was followed by hydrolysis of epoxy groups in the grafting chains to improve the membrane＇s hydrophilie property. Fourier trans- form infrared spectroscopy （FT-IR） and X-ray photoelectron spectroscopy （XPS） measurements confirmed the suc- cessful grafting and hydrolysis of PGMA. The grafting degree of the monomer, measured by periodic acid titration and gravimetric analysis, increased linearly with the polymerization time, while the static water contact angle of the membrane grafted with PGMA or hydrolyzed PGMA linearly decreased. In comparison with the PGMA-grafted membranes, the hydrolyzed PGMA-grafted membranes possess stronger hydrophilicity as indicated by their contact angle and hydration capacity, and as a result they have an improved antifouling property. Therefore, the control of the hydrophilicity of PSF membrane could be realized through adjusting the polymerization time and transforming the functional groups in the grafting chain.
基金supported by National Natural Science Foundation of China(No.20975080)Program for New Century Excellent Talents in University(No.NCET-08-0892)+1 种基金Major State Basic Research Development Program of China(No.2009CB26608)Natural Science Foundation of Ningxia Province(No.NZ0914)
文摘A one-step procedure to hydrophilize monodisperse poly（chloromethyl-styrene-co-divinylbenzene） beads has been presented with 2-hydroxy-3-[4-（hydroxymethyl）-1H-1,2,3-triazol-1-yl]propy1 2-methylacrylate（HTMA） as monomer by surface-initiated atom transfer radical polymerization（SI-ATRP）.The length of the grafted poly（HTMA） chain was varied via controlling the ratio of HTMA to initiator on the surface of the beads.Using these grafted beads as the stationary phase in hydrophilic interaction chromatography,good separation was obtained for nucleosides in the mobile phase of acetonitrile-water.It was also found that the retention time and selectivity of solutes showed a positive relationship with the length of the grafted poly（HTMA） chain.
文摘Surface-attached micropattemed polyelectrolyte brushes on planar solid surfaces are generated using free radical polymerization photo-initiated by self-assembled initiator monolayers. It is shown that the formed patterns can be either negative or positive with different patterning processes.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50805086 and 50730007)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51021064)
文摘The poly (N-isopropylacrylamide) brush was covalently bonded on an initiator-coated silicon wafer via surface-initiated atom transfer radical polymerization. The polymer brush was (76.2±0.1) nm in thickness (by ellipsometer) with a grafting density of ca. 0.27 chains/nm 2 . The tribological properties of the poly (N-isopropylacrylamide) brush were investigated by means of ball-on-disk tests in a rotational mode under water lubrication for tribological application. The experimental results exhibited a low friction coefficient of ca. 0.03. The excellent lubrication property of the brush was due to its amide groups in the polymer chains. It was supposed that the good lubrication property of the brush was attributed to the cross-linked polymer network formed by the hydrogen bond association of N-H…O==C and the water molecular layer adsorbed by the terminal amide groups in the brush. The poly (N-isopropylacrylamide) solution also exhibits a lubrication property due to physical adsorption of the polymer chains.
文摘Narrow-disperse, surface-functionalized ＂living＂ polymer microspheres with uniformly cross-linked structures were prepared by two-stage precipitation copolymerization of styrene and divinylbenzene. The two-stage precipitation polymerization is composed of an initial conventional precipitation polymerization for the nucleation followed by a reverse atom transfer radical polymerization （reverse ATRP） for the controlled polymerization process. The polymerization parameters （including reaction time for the first stage, AIBN amount and monomer loading） have been studied to show significant influences on the morphologies. Moreover, narrower size distribution and an ATRP initiator-functional surface of resulting particles can be obtained by applying reverse ATRP to conventional precipitation polymerization in the second stage. Furthermore, the ＂livingness＂ of the resulting polymer microspheres was testified by their surface modification of poly[2-（dimethylamino） ethyl methacrylate] （PDMAEMA） brushes via surface-initiated ATRP （SI-ATRP）.
基金Supported by the National Natural Science Foundation of China（Nos.51203015, 51243003）.
文摘Polymers grafted from solid surface are being extensively studied with a range of objectives.The most popular living/controlled polymerization used in polymers grafted from solid surfaces is the surface-initiated atom transfer radical polymerization（SI-ATRP）[1,2].An attractive feature of atom transfer radical polymerization（ATRP） is to simultaneously grow chains from multifunctional surface.Thus the grafted polymer with well-defined structures could be designed and controlled.ATRP has proven to be a powerful tool to synthesize homopolymers and copolymers,under easily accessible experimental conditions[3-7].Furthermore it is useful for the functionalization of material surfaces by grafting certain polymers.
基金Supported by the National Natural Science Foundation of China（No.51203015）, the Natural Science Foundation of Jiangsu Province, China~o.BK2012786）, Qing Lan Project and the Changzhou Science and Technology Support Program, China （No.CE20150002）.
文摘The surface ofpoly（ethylene terephthalate）（PET） films is inert, hydrophobic, and incompatible with blood, which has limited its practical bioapplication. In this case, better biocompatibility could be achieved by surface modification. In this study, the grafted copolymer of functional methoxypolyethylene glycol（mPEG） derivatives and styrene from the PET surfaces was prepared via surface-initiated atom transfer radical polymerization（SI-ATRP）. The structures, composition, properties and surface morphology of the grafted PET films were characterized by Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS）, contact angle measurements and scanning electronic microscopy（SEM）. The results indicate that the surface of the PET films has been covered by a thick targeted copolymer layer that converted the hydrophobic surface of PET to an amphiphilic surface. The bacte- rial adhesion and cell culture results indicate the copolymer-grafted PET film may possess good biocompatibility.
