Multi-walled carbon nanotubes （MWCNTs） were grafted with poly（N-vinyl-2-pyrrolidone） and with poly（2- acrylamido-2-methyl-1-propanesulfonic acid） at different compositions by using y-rays technique as initiator....Multi-walled carbon nanotubes （MWCNTs） were grafted with poly（N-vinyl-2-pyrrolidone） and with poly（2- acrylamido-2-methyl-1-propanesulfonic acid） at different compositions by using y-rays technique as initiator. The MWCNTs, MWCNT-graft-PNVP, MWCNT-graft-PAMPS and MWCNTs-graft-P（NVP-co-AMPS） were characterized by Fourier transform infra red （FTIR） spectroscopy, X-ray diffraction （XRD）, thermal gravimetric analysis （TGA）, elemental analysis and high-resolution transmission electron microscopy （HR-TEM）. The results indicated that the grafting processes of PNVP, PAMPS and P（NVP-co-AMPS） occurred on to the surfaces of MWCNTs without destroying the framework of MWCNTs. Tramadol hydrochloride （TH） was loaded as model drug and its release behavior was analyzed via various kinetic models. Release of the loaded TH was studied in simulated gastric fluid （SGF, pH = 1.2） and simulated intestinal fluid （SIF, pH = 7.4） at 37 ℃. Controlled release of TH from grafted MWCNTs was investigated. The outcome results suggest that the grafted MWCNTs could be used as a promising matrix candidate for oral drug delivery system by harmonization between the composition and pH level of the simulated biological fluids.展开更多
Polymeric dielectrics have wide range of applications in the field of electrical energy storage because of their light weight and easy processing. However, the state-of-the-art polymer dielectrics, such as biaxially o...Polymeric dielectrics have wide range of applications in the field of electrical energy storage because of their light weight and easy processing. However, the state-of-the-art polymer dielectrics, such as biaxially orientated polypropylene, could not meet the demand of minimization of electronic devices because of its low energy density. Recently, poly（vinylidene fluoride） （PVDF） based ferroelectric polymers have attracted considerable interests for energy storage applications because of their high permittivity and high breakdown strength. Unfortunately, the high dielectric loss and/or high remnant polarization of PVDF-based polymers seriously limits their practical applications for electrical energy storage. Since the discovery of relaxor ferroelectric behavior was firstly reported in irradiated poly（vinylidene fluoride- trifluoroethylene） （P（VDF-TrFE）） copolyrner, many strategies have been developed to enhanced the electrical energy storage capability, including copolymerization, grafting, blending and fabricating of multilayer How these methods affect the polymorphs, crystallinity, crystal size of PVDF-based polymers and the connection between these microstructures and their corresponding energy storage properties are discussed in detail.展开更多
A novel magnetic chelating adsorbent （CPMS） with iminodiacetate functionality was prepared by polymerization of glycidyl methacrylate-iminodiacetic acid （GMA-IDA） monomer with N, N-methylenebisacrylamide as crossl...A novel magnetic chelating adsorbent （CPMS） with iminodiacetate functionality was prepared by polymerization of glycidyl methacrylate-iminodiacetic acid （GMA-IDA） monomer with N, N-methylenebisacrylamide as crosslinker in the presence of monodisperse magnetic silica microspheres （MS）. CPMS was characterized by IR, SEM, VSM and TGA. The experimental results revealed that MS was embedded in the gel polymer, but the morphology of CPMS was irregular. The saturation magnetization for CPMS was found to be 28.4 emu/g, and the percentage of GMA-IDA polymer grafted on MS was about 46.5%. CPMS were shown to be efficient for the removal of Pb（II） ions at pH 3.0 - 6.0, and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 54.4 mg？g？1 at pH 5.0. Moreover, the adsorption rate of CPMS was fast and it took about 5 minutes to achieve adsorption equilibrium in aqueous solution of lower lead ions concentration.展开更多
文摘Multi-walled carbon nanotubes （MWCNTs） were grafted with poly（N-vinyl-2-pyrrolidone） and with poly（2- acrylamido-2-methyl-1-propanesulfonic acid） at different compositions by using y-rays technique as initiator. The MWCNTs, MWCNT-graft-PNVP, MWCNT-graft-PAMPS and MWCNTs-graft-P（NVP-co-AMPS） were characterized by Fourier transform infra red （FTIR） spectroscopy, X-ray diffraction （XRD）, thermal gravimetric analysis （TGA）, elemental analysis and high-resolution transmission electron microscopy （HR-TEM）. The results indicated that the grafting processes of PNVP, PAMPS and P（NVP-co-AMPS） occurred on to the surfaces of MWCNTs without destroying the framework of MWCNTs. Tramadol hydrochloride （TH） was loaded as model drug and its release behavior was analyzed via various kinetic models. Release of the loaded TH was studied in simulated gastric fluid （SGF, pH = 1.2） and simulated intestinal fluid （SIF, pH = 7.4） at 37 ℃. Controlled release of TH from grafted MWCNTs was investigated. The outcome results suggest that the grafted MWCNTs could be used as a promising matrix candidate for oral drug delivery system by harmonization between the composition and pH level of the simulated biological fluids.
基金support from Special Fund of the National Priority Basic Research of China (No. 2014CB239503)the National Natural Science Foundation of China (Nos. 51522703, 51477096) was acknowledged
文摘Polymeric dielectrics have wide range of applications in the field of electrical energy storage because of their light weight and easy processing. However, the state-of-the-art polymer dielectrics, such as biaxially orientated polypropylene, could not meet the demand of minimization of electronic devices because of its low energy density. Recently, poly（vinylidene fluoride） （PVDF） based ferroelectric polymers have attracted considerable interests for energy storage applications because of their high permittivity and high breakdown strength. Unfortunately, the high dielectric loss and/or high remnant polarization of PVDF-based polymers seriously limits their practical applications for electrical energy storage. Since the discovery of relaxor ferroelectric behavior was firstly reported in irradiated poly（vinylidene fluoride- trifluoroethylene） （P（VDF-TrFE）） copolyrner, many strategies have been developed to enhanced the electrical energy storage capability, including copolymerization, grafting, blending and fabricating of multilayer How these methods affect the polymorphs, crystallinity, crystal size of PVDF-based polymers and the connection between these microstructures and their corresponding energy storage properties are discussed in detail.
文摘A novel magnetic chelating adsorbent （CPMS） with iminodiacetate functionality was prepared by polymerization of glycidyl methacrylate-iminodiacetic acid （GMA-IDA） monomer with N, N-methylenebisacrylamide as crosslinker in the presence of monodisperse magnetic silica microspheres （MS）. CPMS was characterized by IR, SEM, VSM and TGA. The experimental results revealed that MS was embedded in the gel polymer, but the morphology of CPMS was irregular. The saturation magnetization for CPMS was found to be 28.4 emu/g, and the percentage of GMA-IDA polymer grafted on MS was about 46.5%. CPMS were shown to be efficient for the removal of Pb（II） ions at pH 3.0 - 6.0, and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 54.4 mg？g？1 at pH 5.0. Moreover, the adsorption rate of CPMS was fast and it took about 5 minutes to achieve adsorption equilibrium in aqueous solution of lower lead ions concentration.
