A hammer like C 60 conjugated polystyrene was synthesized via atom transfer radical polymerization using bromine ended polystyrene as an initiator.The self assembly aggregating behavior of the hammer like polymer was investigated by DLS,GPC and TEM.Two narrow distributions with hydrodynamic radius 29 5 nm and 1 3 nm were observed in DLS,attributed respectively to the aggregates and single hammer like polymer molecules.In the eluograph of GPC,two distributions were also observed,attributed respectively to the aggregates and single hammer like polymer.In TEM,micelle particles with average diameter 65 nm were observed,agreed well with the results obtained by DLS.The diameter of aggregates of two hammer like C 60 conjugated polystyrene samples was compared and possible explanations were proposed.
Self assembly of an amphiphilic diblock copolymer polysyrene b polyvinylbenzoic acid in ethanol,which is a selective solvent for the polybenzoic acid segment was studied by means of transmission electron microscopy.The diblock copolymers can self assemble into nano scale aggregates with polystyrene segment as the core and polyvinylbenzoic acid segment as the corona.The morphology of the aggregates is mainly controlled by the ratio of the two segment of the diblock copolymer.As the content of the ethanol insoluble polystyrene segment increased,the morphology can be changed from spheres to rods.The diameter of the aggregates increases slightly with concentration and decreases with the addition of CoCl 2 salt.
To achieve well defined amphiphilic C 60 containing macromolecules,C 60 conjugated polystyrene(C 60 PS)was first synthesized via tandem atom transfer radical polymerization(ATRP).With the help of tetrabutylammonium bromide(TBAB),taurine(2 aminoethanesulfonic acid) can be carried from water phase into the phenyl chloride phase and then react with C 60 PS.The final product——taurine modified C 60 conjugated polystyrene—is a novel type of highly asymmetric amphiphilic diblock copolymers,which can form spherical crew cut type micelles by adding water in small amounts into its tetrahydrofuran solution.UV vis spectroscopy and trasmission electronic microscopy have been employed to monitor the aggregating process of these spherical micelles and observe their final morphology respectively.
Atom transfer radical polymerization of protected 2 hydroxyethyl acrylate (HEA\|TMS) was conducted to prepare well\|defined bromo\|terminated macroinitiators,which were further allowed to react with large excess amount of C 60 under ATRP condition.A well defined hammer shaped C 60 PHEA was then obtained by hydrolysis of C 60 PHEA TMS under mild conditions.A TEM observation of the association behavior of these well defined hammer like C 60 PHEA macromolecules showed that they assemble into spherical vesicles in water.Their characteristic inner water phase was further confirmed by fluorescence probe method.Also,it was found that the size of vesicles decreased as the increase of molecular weight of PHEA.
