| Macroscopic lamellae orientations of diblock copolymer induced by dynamic shear |
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| 作者姓名： | 张红东 杨玉良 |
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| 作者单位： | Department of Macromolecular Science ana Lanoratory of Macromolecular Engineering，Fudan University，Shanghai 200433，China，Department of Macromolecular Science ana Lanoratory of Macromolecular Engineering，Fudan University，Shanghai 200433，China |
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| 基金项目： | supported by the National Natural Science Foundation of China，the Trans-Century-Talent Foundation of the State Education Commission of China，the Science，Technology Foundation of Shanghai |
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| 摘 要： | Computer simulation based on the coupled map lattices has been carried out for morphologies of the diblock copolymeric system under applied periodic shear deformation.The main effort is concentrated on the influence of pre-annenling history on the lamellae orientations in dynamically sheared diblock copolymers.It is found that whatever the quenching temperature is,the perpendicular orientation (i.e.the lamellae normal is parallel to the vorticity axis) is always observed if the dynamic shear deformation with shear amplitude F=1.0 and reduced shear frequency=0.005 is applied during annealing.In contrast to that,the parallel orientation (i.e.the lamellae normal is parallel to the velocity gradient direction) is observed if the dynamic shear with the same amplitude and frequency is applied to a thoroughly annealed (with the annealing time t>4 000) diblock copolymer.Therefore,it is pointed out that the selection of lamellar orientations in dynamically sheared diblock copolymers is not solely dependent on th
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| 收稿时间： | 6 June 1996 |
Macroscopic lamellae orientations of diblock copolymer induced by dynamic shear |
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| Hongdong Zhang,Yuliang Yang.Macroscopic lamellae orientations of diblock copolymer induced by dynamic shear[J].Science in China(Chemistry),1997,40(1):53-60. |
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| Authors: | Hongdong Zhang Yuliang Yang |
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| Institution: | (1) Department of Macromolecular Science and Laboratory of Macromolecular Engineering, Fudan University, 200433 Shanghai, China;(2) Institute of Chemistry, Chinese Academy of Sciences, 100080 Beijing, China |
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| Abstract: | Computer simulation based on the coupled map lattices has been carried out for morphologies of the diblock copolymeric system under applied periodic shear deformation.The main effort is concentrated on the influence of pre-annenling history on the lamellae orientations in dynamically sheared diblock copolymers.It is found that whatever the quenching temperature is,the perpendicular orientation (i.e.the lamellae normal is parallel to the vorticity axis) is always observed if the dynamic shear deformation with shear amplitude F=1.0 and reduced shear frequency=0.005 is applied during annealing.In contrast to that,the parallel orientation (i.e.the lamellae normal is parallel to the velocity gradient direction) is observed if the dynamic shear with the same amplitude and frequency is applied to a thoroughly annealed (with the annealing time t>4 000) diblock copolymer.Therefore,it is pointed out that the selection of lamellar orientations in dynamically sheared diblock copolymers is not solely dependent on the shear frequency and the quench depth,the pre-annealing history has a very strong influence on the selection of lamellar orientations.Thus,the contradictions existing in literature could be explained according to the thermal history of the samples and the results of this study |
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| Keywords: | block copolymer microphase separation dynamic shear lamellar morphology coupled map lattices |
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