In the present work,novel dual-functionalized hollow polymer particles （DF-HPP） with high density of carboxylate and amino dual functional groups have been specially designed and fabricated to serve as high-performa...In the present work,novel dual-functionalized hollow polymer particles （DF-HPP） with high density of carboxylate and amino dual functional groups have been specially designed and fabricated to serve as high-performance adsorbent for selective removal of basic dye （methylene blue,b-MB,as a model dye）.Due to both the high surface area and the extremely high density of carboxylate and amino groups,the DF-HPPs exhibited excellent adsorption property for methylene blue （b-MB）,including high adsorption capacity,fast adsorption/desorption rates,unique pH-sensitivity and easy recovery.The equilibrium adsorption data of b-MB on the DF-HPPs were evaluated using Freundlich and Langmuir isotherm models,and the equilibrium isotherm was better fit with Langmuir model with a maximum adsorption capacity of 538.8 mg/g at pH 12.More interestingly,the DF-HPPs showed a significant pH-dependent equilibrium adsorption capacity,which decreased dramatically from 516.1 mg/g to 24 mg/g as the solution pH decreased from 12 to 3.The dye-adsorbed DF-HPPs can be facilely and rapidly regenerated under mild condition （under weak acidic solution,pH 3,in 30 min） to recover both b-MB and the DF-HPPs,and the regenerated DF-HPPs can be reused for dye removal with high efficiency,indicating the exceptional recyclability of the DF-HPPs.展开更多
Hollow particles were prepared by the treatment of styrene-metbacrylic acid copolymer particles with alkali/cooling method. The influences of stirring position （in aqueous phase or at the interface of O/W） and stirr...Hollow particles were prepared by the treatment of styrene-metbacrylic acid copolymer particles with alkali/cooling method. The influences of stirring position （in aqueous phase or at the interface of O/W） and stirring speed （90, 110 and 240 r/min） on the formation of hollow particles were investigated. It is found that the soft stirring in aqueous phase at 90 r/min leads to the formation of monohollow particles, while the violent stirring at the interface of O/W and 240 r/min gives non-hollow products. In contrast, the weak stirring in aqueous phase at 110 r/min results in sterically heterogeneous dispersion of methacrylic acid-rich regions within the original particles, and hence the formation of multihollow particles. Further investigation indicates that the change of stirring efficiency provides a way to tune the diffusion behavior of monomer styrene, and therefore influences the distribution of methacrylic acid units in the original particles as well as the morphology of the treated particles.展开更多
Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methac...Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).展开更多
文摘In the present work,novel dual-functionalized hollow polymer particles （DF-HPP） with high density of carboxylate and amino dual functional groups have been specially designed and fabricated to serve as high-performance adsorbent for selective removal of basic dye （methylene blue,b-MB,as a model dye）.Due to both the high surface area and the extremely high density of carboxylate and amino groups,the DF-HPPs exhibited excellent adsorption property for methylene blue （b-MB）,including high adsorption capacity,fast adsorption/desorption rates,unique pH-sensitivity and easy recovery.The equilibrium adsorption data of b-MB on the DF-HPPs were evaluated using Freundlich and Langmuir isotherm models,and the equilibrium isotherm was better fit with Langmuir model with a maximum adsorption capacity of 538.8 mg/g at pH 12.More interestingly,the DF-HPPs showed a significant pH-dependent equilibrium adsorption capacity,which decreased dramatically from 516.1 mg/g to 24 mg/g as the solution pH decreased from 12 to 3.The dye-adsorbed DF-HPPs can be facilely and rapidly regenerated under mild condition （under weak acidic solution,pH 3,in 30 min） to recover both b-MB and the DF-HPPs,and the regenerated DF-HPPs can be reused for dye removal with high efficiency,indicating the exceptional recyclability of the DF-HPPs.
基金Project supported by China Scholarship CouncilProject(09JJ3100) supported by Hunan Provincial Natural Science Foundation of China
文摘Hollow particles were prepared by the treatment of styrene-metbacrylic acid copolymer particles with alkali/cooling method. The influences of stirring position （in aqueous phase or at the interface of O/W） and stirring speed （90, 110 and 240 r/min） on the formation of hollow particles were investigated. It is found that the soft stirring in aqueous phase at 90 r/min leads to the formation of monohollow particles, while the violent stirring at the interface of O/W and 240 r/min gives non-hollow products. In contrast, the weak stirring in aqueous phase at 110 r/min results in sterically heterogeneous dispersion of methacrylic acid-rich regions within the original particles, and hence the formation of multihollow particles. Further investigation indicates that the change of stirring efficiency provides a way to tune the diffusion behavior of monomer styrene, and therefore influences the distribution of methacrylic acid units in the original particles as well as the morphology of the treated particles.
文摘Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).
