Topological constraint between softmatter molecules

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K05255
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biological physics/Chemical physics/Soft matter physics
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Suzuki Jiro 大学共同利用機関法人高エネルギー加速器研究機構, 計算科学センター, 准教授 (40415047)
• Research Collaborator: MATSUSHITA yushu ; TAKANO atsushi
• Project Period (FY): 2015-10-21 – 2019-03-31
• Keywords: ソフトマター / リングポリマー / トポロジー / 分子間相互作用 / シミュレーション

Outline of Final Research Achievements

Inter-molecular interaction between soft-matter molecules, ring polymers, was studied. We employ a Metropolis Monte-Carlo simulation in this study, where a polymer molecule was composed of segments and bonds. Polymer segments bearing excluded volumes were placed on lattice points of a face-centered cubic (FCC) lattice. We estimated interaction between two simple ring chains catenated in a molecule in dilute solution at the theta-temperature of trivial-rings. Under that temperature the mean-square distance between two rings in a catenated molecule was obtained and compared with that of the simple model composed of two circles in three dimensions, where interaction between circles was set as zero. The mean-square distances simulated were constantly larger than those of the model owing to the excluded volume of rings in a catenated molecule. Interaction between simple rings catenated each other is positive at the theta-temperature of trivial-rings.

Free Research Field

ソフトマターの物理

Academic Significance and Societal Importance of the Research Achievements

紐状の柔らかい分子からなる「ソフトマター」の分子間相互作用をトポロジーで制御することを目的とした。高分子鎖が末端を持たないトポロジーをとるときに末端がある場合とどのように異なるのか、あるいはリングのトポロジーがどのように相互作用に影響するかをシミュレーション法で検討した。計算効率をあげるため、FCC格子上で分子鎖を移動させるアルゴリズムを研究開発した。最も単純なTrivial-ringが相互陥入したカテナン型リングポリマーが、カテナン分子内における二つのリングの相互作用について検討を行い、セグメント間相互作用が消失するθ状態において、リング間の相互作用が反発力であることを明らかにした。