1993 Fiscal Year Final Research Report Summary
Computer simulation studies on shapes of block copolymers
| Project/Area Number |
04650797
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子物性・高分子材料（含機械材料）
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HATANO Akira The University of Tokyo, College of Arts and Sciences, Assistant, 教養学部, 助手 (10012395)
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| Co-Investigator(Kenkyū-buntansha) |
NOGUCHI Tohru The University of Tokyo, College of Arts and Sciences, Assistant, 教養学部, 助手 (90153444)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Computer Simulation / Diblock Copolymer / Lamellar Phase / Path Integral / Gaussian Backbone / Folding and Periodic Boundary Condition |
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| Research Abstract |
Segment distribution profiles of symmetric A-B diblock copolymers in their lamellar phase are simulated by means of the path integral method. Paths are generated by linking the Gaussian random vectors of the mean length being ROO<D>, where D is the spatial dimensions. The excluded volume interactions and the repulsive interactions between segments of A- and B-block are included. When the system stays in the lamellar plane, the vector from the center of gravity of, say, A-block to that of B-block of the chain in the system is aligned to be perpendicular to the lamellar plane, and the junction point is in the center plane of the segregation. We a priori have prepared this condition. Further, the condensed lamellar phase is generated by the folding boundary conditions (mirror reflections) along the perpendicular axis (x-axis) to the lamellar plane at the middle plane of the highest density of A/B segments and the periodic bounary conditions along the parallel axs (y- and z-axis). The segment distributions in the cell resulted from the conditions must be flat at the reflected plane along the x-axis and constant along the y- and z-axis, so these are necessarily satisfied self-consistently. At first we generate paths by changing partially the preceding path under the constrained gaussian chain, and choose the new by the Metropolis choice. Secondly, we generate many primitive Gaussian chains putting the interactions and weighting by taking account of the statistical weight. Satisfying the above conditions we find the profile deviated from the condensed system which consists of the Gaussian (i.e.non-interacting) chains. Our simulations prefer rather the case of the weak segregations. Recently, a new model of the path on two dimensional space are developed. By this, we can find the evolution of the lamellar phase. This is our future problems.
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