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
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.
