In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, t...In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, then droping water into the corresponding copolymer solution to induce the self-assembly. The aggregates prepared were characterized with TEM and AFM techniques. The experimental results demonstrated that the self-assembled vesicles were formed when THF and 1,4-dioxane were used as the common solvents to dissolve the copolymer, comparatively, using DMF as the common solvent resulted in the formation of spherical aggregates. The self-assembled aggregates observed, possessing hierarchical structures, could be used as either the nanostructures themselves for drug delivery systems, separations, catalysts, and so on, or templates or building blocks for more complex structures.展开更多
用扫描电子显微镜对聚苯乙烯 b 聚丙烯酸 (PS b PAA)嵌段共聚物在水中自组装形貌进行了观察。结果表明 :外界环境和制样方法能够影响聚合物的自组装和聚集情况。 0℃时 ,PS38 b PAA2 10 胶束聚集形成纺锤状结构。而在临界条件下 ,缓慢...用扫描电子显微镜对聚苯乙烯 b 聚丙烯酸 (PS b PAA)嵌段共聚物在水中自组装形貌进行了观察。结果表明 :外界环境和制样方法能够影响聚合物的自组装和聚集情况。 0℃时 ,PS38 b PAA2 10 胶束聚集形成纺锤状结构。而在临界条件下 ,缓慢改变体系冷冻 解冻循环次数 ,则会得到这些纺锤结构的花状聚集体。展开更多
The halogen-terminated polymers (PS—X) were obtained by living free radical polymerization. Through the end-group transformation action of AgClO4, poly(styrene-b-2-methyl-2-oxazoline) block copolymer [P(s-b-Me-...The halogen-terminated polymers (PS—X) were obtained by living free radical polymerization. Through the end-group transformation action of AgClO4, poly(styrene-b-2-methyl-2-oxazoline) block copolymer [P(s-b-Me-OXZ)] was synthesized by transforming the living free radical polymerization into ring-opening polymerization of 2-methyl-2-oxazoline.The obtained copolymers were characterized by SEC, IR and 1H NMR. The suitable polymerization conditions for block copolymer synthesis were studied.展开更多
By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the...By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the effects on sol particle growth and network &morphology control were discussed in detail, and then the model on sol particle growing was suggested on the basis of growth unit theory of anion coordinate polyhedron. The results showed that PEO PPO PEO additive limited particle growth but also restrained particle agglomeration and then made the SiO2 sol high stable. It was found that the action of EPE was similar to that of organic structure directing agent and made the sol cluster cross linked branch network.展开更多
文摘In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, then droping water into the corresponding copolymer solution to induce the self-assembly. The aggregates prepared were characterized with TEM and AFM techniques. The experimental results demonstrated that the self-assembled vesicles were formed when THF and 1,4-dioxane were used as the common solvents to dissolve the copolymer, comparatively, using DMF as the common solvent resulted in the formation of spherical aggregates. The self-assembled aggregates observed, possessing hierarchical structures, could be used as either the nanostructures themselves for drug delivery systems, separations, catalysts, and so on, or templates or building blocks for more complex structures.
文摘The halogen-terminated polymers (PS—X) were obtained by living free radical polymerization. Through the end-group transformation action of AgClO4, poly(styrene-b-2-methyl-2-oxazoline) block copolymer [P(s-b-Me-OXZ)] was synthesized by transforming the living free radical polymerization into ring-opening polymerization of 2-methyl-2-oxazoline.The obtained copolymers were characterized by SEC, IR and 1H NMR. The suitable polymerization conditions for block copolymer synthesis were studied.
文摘By means of TEM, SDP, 29Si NMR etc analysis, the behavior of the Polyethylene Oxide (PEO) Polypropylene Oxide (PPO) Polyethylene Oxide (PEO) as organic modifier on SiO2 sol gel in the basic media was investigated; the effects on sol particle growth and network &morphology control were discussed in detail, and then the model on sol particle growing was suggested on the basis of growth unit theory of anion coordinate polyhedron. The results showed that PEO PPO PEO additive limited particle growth but also restrained particle agglomeration and then made the SiO2 sol high stable. It was found that the action of EPE was similar to that of organic structure directing agent and made the sol cluster cross linked branch network.