A facile and selective route for O-alkylation of highly hydrophilic, multifunctional hyperbranched polyglycerol (PG) under non-aqueous phase transfer catalyzed conditions in dimethyl sulfoxide was developed, through w...A facile and selective route for O-alkylation of highly hydrophilic, multifunctional hyperbranched polyglycerol (PG) under non-aqueous phase transfer catalyzed conditions in dimethyl sulfoxide was developed, through which several kinds of groups were introduced onto PG.展开更多
Reversible assembly and disassembly of rodlike large complex micelles have been achieved by applying photoswitching of supramolecular inclusion and exclusion of azobenzene-functionalized hyperbranched polyglycerol and...Reversible assembly and disassembly of rodlike large complex micelles have been achieved by applying photoswitching of supramolecular inclusion and exclusion of azobenzene-functionalized hyperbranched polyglycerol and acyclodextrin as driv ing force, promising a versatile system for selfassembly switched by light. Hydrogennuclear magnetic resonance （H NMR） and Fourier transform infrared （FTIR） spectroscopy were applied to characterize the azobenzenefunctionalized hyperbranched polyglycerol. Atomic force microscopy （AFM）, transmission electron microscopy （TEM） and dynamic laser light scattering （DLS） were employed to investigate and track the morphology of the rodlike large complex micelles before and after irradiation of UV light.展开更多
In this paper, we report the synthesis and self-assembly of double-hydrophilic hyperbranched graft copolymers of HPG-g-PDMAEMA, which consist of a hyperbranched polyglycerol (HPG) core and several grafted poly(2-(dime...In this paper, we report the synthesis and self-assembly of double-hydrophilic hyperbranched graft copolymers of HPG-g-PDMAEMA, which consist of a hyperbranched polyglycerol (HPG) core and several grafted poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) arms. HPG was synthesized by cationic polymerization. Then HPG-Br macroinitiator was obtained by esterification of HPG with 2-bromoisobutyryl bromide, which was subsequently used in the preparation of HPG-g-PDMAEMA graft copolymers through atom transfer radical polymerization (ATRP) of DMAEMA monomers. The molecular structures were studied by 1H NMR and GPC. The pyrene-based fluorescent probe method, 1H NMR and DLS were used to study the self-assembly behavior of HPG-g-PDMAEMA. The drug loading and pH-responsive release properties of HPG-g-PDMAEMA were also investigated by using coumarin 102 as a model drug. The results show that the HPG-g-PDMAEMA micelles can continuously release and re-encapsulate coumarin 102 as the pH continuously changes from 11.5 to 2.5; however, this process is not totally reversible.展开更多
Spherical molecular brushes with amphiphilic heteroarms were facilely synthesized by grafting the arms of hydrophobic 2-azidoethyle palmitate and hydrophilic monoazide-terminated poly(ethylene glycol) onto the core of...Spherical molecular brushes with amphiphilic heteroarms were facilely synthesized by grafting the arms of hydrophobic 2-azidoethyle palmitate and hydrophilic monoazide-terminated poly(ethylene glycol) onto the core of alkyne-modified hyperbranched polyglycerol (HPG) with high molecular weight (Mn=122 kDa) via one-pot parallel click chemistry.The parallel click grafting strategy was demonstrated to be highly efficient (～100%),very fast (～ 2 h) and well controllable to the amphilicity of molecular brushes.Through adjusting the feeding ratio of hydrophobic and hydrophilic arms,a series of brushes with different arm ratios were readily obtained.The resulting miktoarms hyperbranched polymer brushes (HPG-g-C16/PEG350) were characterized by hydrogen-nuclear magnetic resonance (1H NMR),Fourier transform infrared (FT-IR) spectroscopy,gel permeation chromatography (GPC),and differential scanning calorimetry (DSC) measurements.The spherical molecular brushes showed high molecular weights up to 230 kDa,and thus could be visualized by atomic force microscopy (AFM).AFM and dynamic laser light scattering (DLS) were employed to investigate the self-assembly properties of amphiphilic molecular brushes with closed proportion of hydrophobic and hydrophilic arms.The brushes could self-assemble hierarchically into spherical micelles,and network-like fibre structures,and again spherical micelles by addition of n-hexane into the dichloromethane or chloroform solution of brushes.In addition,this kind of miktoarms polymer brush also showed the ability of dye loading via host-guest encapsulation,which promises the potential application of spherical molecular brushes in supramolecular chemistry.展开更多
文摘A facile and selective route for O-alkylation of highly hydrophilic, multifunctional hyperbranched polyglycerol (PG) under non-aqueous phase transfer catalyzed conditions in dimethyl sulfoxide was developed, through which several kinds of groups were introduced onto PG.
基金supported by the National Natural Science Foundation of China (20974093)the National Basic Research Program of China (973 Program, 2007CB936004)+3 种基金Qianjiang Talent Foundation of Zhejiang Province (2010R10021)the Fundamental Research Funds for the Central Universities (2009QNA4040)Zhejiang Provincial Natural Science Foundation of China (R4110175)Research Fund for the Doctoral Program of Higher Education of China ( 20100101110049)
文摘Reversible assembly and disassembly of rodlike large complex micelles have been achieved by applying photoswitching of supramolecular inclusion and exclusion of azobenzene-functionalized hyperbranched polyglycerol and acyclodextrin as driv ing force, promising a versatile system for selfassembly switched by light. Hydrogennuclear magnetic resonance （H NMR） and Fourier transform infrared （FTIR） spectroscopy were applied to characterize the azobenzenefunctionalized hyperbranched polyglycerol. Atomic force microscopy （AFM）, transmission electron microscopy （TEM） and dynamic laser light scattering （DLS） were employed to investigate and track the morphology of the rodlike large complex micelles before and after irradiation of UV light.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20774057 & 50633010)National Basic Research Program (973 Project, Grant No. 2007CB808000)+1 种基金the Basic Research Foundation of Shanghai Science and Technique Committee (Grant No. 07DJ14004)the Shanghai Leading Academic Discipline Project (Grant No. B202)
文摘In this paper, we report the synthesis and self-assembly of double-hydrophilic hyperbranched graft copolymers of HPG-g-PDMAEMA, which consist of a hyperbranched polyglycerol (HPG) core and several grafted poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) arms. HPG was synthesized by cationic polymerization. Then HPG-Br macroinitiator was obtained by esterification of HPG with 2-bromoisobutyryl bromide, which was subsequently used in the preparation of HPG-g-PDMAEMA graft copolymers through atom transfer radical polymerization (ATRP) of DMAEMA monomers. The molecular structures were studied by 1H NMR and GPC. The pyrene-based fluorescent probe method, 1H NMR and DLS were used to study the self-assembly behavior of HPG-g-PDMAEMA. The drug loading and pH-responsive release properties of HPG-g-PDMAEMA were also investigated by using coumarin 102 as a model drug. The results show that the HPG-g-PDMAEMA micelles can continuously release and re-encapsulate coumarin 102 as the pH continuously changes from 11.5 to 2.5; however, this process is not totally reversible.
基金supported by the National Natural Science Foundation of China(50773038 & 20974093)National Basic Research Program of China(973 Program)(2007CB936000)+2 种基金the Fundamental Research Funds for the Central Universities(2009QNA4040)Qianjiang Talent Foundation of Zhejiang Province(2010R10021)the Foundation for the Author of National Excellent Doctoral Dissertation of China(200527)
文摘Spherical molecular brushes with amphiphilic heteroarms were facilely synthesized by grafting the arms of hydrophobic 2-azidoethyle palmitate and hydrophilic monoazide-terminated poly(ethylene glycol) onto the core of alkyne-modified hyperbranched polyglycerol (HPG) with high molecular weight (Mn=122 kDa) via one-pot parallel click chemistry.The parallel click grafting strategy was demonstrated to be highly efficient (～100%),very fast (～ 2 h) and well controllable to the amphilicity of molecular brushes.Through adjusting the feeding ratio of hydrophobic and hydrophilic arms,a series of brushes with different arm ratios were readily obtained.The resulting miktoarms hyperbranched polymer brushes (HPG-g-C16/PEG350) were characterized by hydrogen-nuclear magnetic resonance (1H NMR),Fourier transform infrared (FT-IR) spectroscopy,gel permeation chromatography (GPC),and differential scanning calorimetry (DSC) measurements.The spherical molecular brushes showed high molecular weights up to 230 kDa,and thus could be visualized by atomic force microscopy (AFM).AFM and dynamic laser light scattering (DLS) were employed to investigate the self-assembly properties of amphiphilic molecular brushes with closed proportion of hydrophobic and hydrophilic arms.The brushes could self-assemble hierarchically into spherical micelles,and network-like fibre structures,and again spherical micelles by addition of n-hexane into the dichloromethane or chloroform solution of brushes.In addition,this kind of miktoarms polymer brush also showed the ability of dye loading via host-guest encapsulation,which promises the potential application of spherical molecular brushes in supramolecular chemistry.
