Micron-sized polymer particles from single poly(4-butyltriphenylamine) (PBTPA) homopolymer, binary polymer blend [PBTPA/poly(methyl methacrylate) (PMMA)], and ternary polymer blend (PBTPA/PBTPA-b-PMMA/PMMA) via a solv...Micron-sized polymer particles from single poly(4-butyltriphenylamine) (PBTPA) homopolymer, binary polymer blend [PBTPA/poly(methyl methacrylate) (PMMA)], and ternary polymer blend (PBTPA/PBTPA-b-PMMA/PMMA) via a solvent evaporation method, and the surface morphologies and inside structure of resulting particles were investigated. Spherical homopolymer particles with smooth surface were resulted from PBTPA with low molecular weight. In the case of binary blends (PBTPA/PMMA = 1/1), Janus (low molecular weight) and dumbbell (high molecular weight) type morphologies were observed. The particles based on ternary blends containing PBTPA-b-PMMA showed core-shell type morphologies (PMMA;core, PBTPA;shell). Degree of engulfment of PMMArich domain increased with the content of the block copolymer. The decrease of domain size was not observed although the block copolymer had a suitable structure as a compatibilizer for the blend. It was also found that the initial concentration of polymer solution had an effect on the final morphology.展开更多
Microspheres based on binary polymer blend consisting of polystyrene (PSt), poly (methyl methacrylate) (PMMA), block copolymer comprising PSt and PMMA subunits, and ternary polymer blend consisting of PSt, PMMA, and b...Microspheres based on binary polymer blend consisting of polystyrene (PSt), poly (methyl methacrylate) (PMMA), block copolymer comprising PSt and PMMA subunits, and ternary polymer blend consisting of PSt, PMMA, and block copolymer were fabricated by a solvent evaporation method, in which a polymer solution in dichloromethane was dispersed in water phase with the aid of a homogenizer to obtain an O/W emulsion followed by solvent evaporation with agitation to solidify the polymer. In the case of ternary blend, the effect of block copolymer content on the morphology of resulting spheres was investigated. Ternary blends afforded the bi-compartmental morphologies, the intermediate morphology between Janus and core-shell, which was confirmed by TEM observation. Seed polymerization of St or MMA was also carried out utilizing the resulting microspheres as seed particles in order to control the shape, and the surface morphology of particles. The particles with snowman-like morphology were obtained by seed polymerization of St using PSt/PMMA binary blend microspheres as seed particles. Surface roughness was controlled by the polymerization of MMA in the block copolymer seed, and that of St in the ternary blend seed.展开更多
In order to mimic hierarchical nanostructures in nature,particles of polymer blends consisting of poly(4-butyltriphenylamine)(PBTPA),poly(methyl methacrylate)(PMMA)and PBTPA-block-PMMA were fabricated by a solvent eva...In order to mimic hierarchical nanostructures in nature,particles of polymer blends consisting of poly(4-butyltriphenylamine)(PBTPA),poly(methyl methacrylate)(PMMA)and PBTPA-block-PMMA were fabricated by a solvent evaporation method.Effects of the molecular weight and the chemical composition of PBTPA-b-PMMA,molecular weights of homopolymers,and the composition of the blend on the morphology were investigated.The polymer blend particle consisting of PBTPA and PMMA homopolymers exhibited thermodynamically favored core-shell structure,in which more hydrophilic PMMA-shell surrounded PBTPA-core.The addition of 10 wt%of PBTPA-b-PMMA caused the morphological transition from core-shell toJanus or inversed core-shell,in which PBTPA-shell surrounded PMMA-core,depending on the molecular weight of PBTPA segment in PBTPA-b-PMMA.When the molecular weight of PMMA segment was higher than that of PMMA homopolymer,watermelon-like particles in which small PBTPA domain less than 80 nm dispersed in the PMMA domain surrounded by PBTPA shell were observed.As the ratio of PBTPA-b-PMMA increased,the interface of the macrophase separation became obscure.At 50 wt%of the PBTPA-b-PMMA,only microphase separation was observed.The measurement of interfacial tension by pendant drop method demonstrated that PBTPA-b-PMMA lower the interfacial tension between PBTPA and the aqueous phase to the value similar to that of PMMA with the aqueous phase.展开更多
Block copolymers(BCPs)can automatically assemble into various regulated nanoparticles when they are confined within the emulsion droplet be-cause of the structural frustration of polymer chains and the soft template e...Block copolymers(BCPs)can automatically assemble into various regulated nanoparticles when they are confined within the emulsion droplet be-cause of the structural frustration of polymer chains and the soft template effect of the oil/water interface.In the past few years,great efforts have been made to regulate the morphologies of the resulting BCP particles.In this review article,various strategies for tuning oil/water interfacial prop-erties to engineer the as-formed BCP particles were summarized.Then,the comprehensive scenarios of the applications of the resulting BCP parti-cles were discussed.Finally,the future tendency and challenge of the self-assembly of BCPs confined in emulsion droplet were suggested.展开更多
The solid state morphology of the tri block copolymer PS b PCEMA b PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After ...The solid state morphology of the tri block copolymer PS b PCEMA b PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After being blended with polystyrene with the mass ratio of 1∶0 4, the morphology showed cylinder structure. With PS as continous phase, PCEMA and PtBA phases formed cylinders with PCEMA as outer layer. The nanofibres can be got and dispersed in good solvents of PS when the PCEMA phase was crosslinked. The t butyl group in PtBA phase can be cleavaged by reacting with TMSI, and nanofibres changed to nanotubes finally. It has the great potential applications, such as in the preparation of nanowires, template polymerization, nano reactor etc ..展开更多
文摘Micron-sized polymer particles from single poly(4-butyltriphenylamine) (PBTPA) homopolymer, binary polymer blend [PBTPA/poly(methyl methacrylate) (PMMA)], and ternary polymer blend (PBTPA/PBTPA-b-PMMA/PMMA) via a solvent evaporation method, and the surface morphologies and inside structure of resulting particles were investigated. Spherical homopolymer particles with smooth surface were resulted from PBTPA with low molecular weight. In the case of binary blends (PBTPA/PMMA = 1/1), Janus (low molecular weight) and dumbbell (high molecular weight) type morphologies were observed. The particles based on ternary blends containing PBTPA-b-PMMA showed core-shell type morphologies (PMMA;core, PBTPA;shell). Degree of engulfment of PMMArich domain increased with the content of the block copolymer. The decrease of domain size was not observed although the block copolymer had a suitable structure as a compatibilizer for the blend. It was also found that the initial concentration of polymer solution had an effect on the final morphology.
文摘Microspheres based on binary polymer blend consisting of polystyrene (PSt), poly (methyl methacrylate) (PMMA), block copolymer comprising PSt and PMMA subunits, and ternary polymer blend consisting of PSt, PMMA, and block copolymer were fabricated by a solvent evaporation method, in which a polymer solution in dichloromethane was dispersed in water phase with the aid of a homogenizer to obtain an O/W emulsion followed by solvent evaporation with agitation to solidify the polymer. In the case of ternary blend, the effect of block copolymer content on the morphology of resulting spheres was investigated. Ternary blends afforded the bi-compartmental morphologies, the intermediate morphology between Janus and core-shell, which was confirmed by TEM observation. Seed polymerization of St or MMA was also carried out utilizing the resulting microspheres as seed particles in order to control the shape, and the surface morphology of particles. The particles with snowman-like morphology were obtained by seed polymerization of St using PSt/PMMA binary blend microspheres as seed particles. Surface roughness was controlled by the polymerization of MMA in the block copolymer seed, and that of St in the ternary blend seed.
基金supported by Institute of Global Innovation Research in Tokyo University of Agriculture and Technology(TUAT).
文摘In order to mimic hierarchical nanostructures in nature,particles of polymer blends consisting of poly(4-butyltriphenylamine)(PBTPA),poly(methyl methacrylate)(PMMA)and PBTPA-block-PMMA were fabricated by a solvent evaporation method.Effects of the molecular weight and the chemical composition of PBTPA-b-PMMA,molecular weights of homopolymers,and the composition of the blend on the morphology were investigated.The polymer blend particle consisting of PBTPA and PMMA homopolymers exhibited thermodynamically favored core-shell structure,in which more hydrophilic PMMA-shell surrounded PBTPA-core.The addition of 10 wt%of PBTPA-b-PMMA caused the morphological transition from core-shell toJanus or inversed core-shell,in which PBTPA-shell surrounded PMMA-core,depending on the molecular weight of PBTPA segment in PBTPA-b-PMMA.When the molecular weight of PMMA segment was higher than that of PMMA homopolymer,watermelon-like particles in which small PBTPA domain less than 80 nm dispersed in the PMMA domain surrounded by PBTPA shell were observed.As the ratio of PBTPA-b-PMMA increased,the interface of the macrophase separation became obscure.At 50 wt%of the PBTPA-b-PMMA,only microphase separation was observed.The measurement of interfacial tension by pendant drop method demonstrated that PBTPA-b-PMMA lower the interfacial tension between PBTPA and the aqueous phase to the value similar to that of PMMA with the aqueous phase.
基金Y.Z acknowledges the financial support of Zhejiang Provincial Natural Science Foundation of China(LR20E030003)X.C acknowledges the financial support of National Natural Science FoundationofChina(52003070).
文摘Block copolymers(BCPs)can automatically assemble into various regulated nanoparticles when they are confined within the emulsion droplet be-cause of the structural frustration of polymer chains and the soft template effect of the oil/water interface.In the past few years,great efforts have been made to regulate the morphologies of the resulting BCP particles.In this review article,various strategies for tuning oil/water interfacial prop-erties to engineer the as-formed BCP particles were summarized.Then,the comprehensive scenarios of the applications of the resulting BCP parti-cles were discussed.Finally,the future tendency and challenge of the self-assembly of BCPs confined in emulsion droplet were suggested.
文摘The solid state morphology of the tri block copolymer PS b PCEMA b PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After being blended with polystyrene with the mass ratio of 1∶0 4, the morphology showed cylinder structure. With PS as continous phase, PCEMA and PtBA phases formed cylinders with PCEMA as outer layer. The nanofibres can be got and dispersed in good solvents of PS when the PCEMA phase was crosslinked. The t butyl group in PtBA phase can be cleavaged by reacting with TMSI, and nanofibres changed to nanotubes finally. It has the great potential applications, such as in the preparation of nanowires, template polymerization, nano reactor etc ..
