1996 Fiscal Year Annual Research Report

鎖状異種高分子(linear heteropolymers)の統計力学的研究

Research Project

Project/Area Number	07640508
Research Institution	Kanazawa University
Principal Investigator	樋渡保秋金沢大学, 理学部, 教授 (20019491)
Co-Investigator(Kenkyū-buntansha)	高須昌子金沢大学, 理学部, 助教授 (50202148)
Keywords	ヘテロポリマー / グロビュール転移 / 分子の折りたたみ
Research Abstract	本研究は、生体分子RNAなどの高次(2次元、3次元)分子構造の形態転移などについて考察する目的から、簡単なモデルとして、等価、等量の正に帯電したモノマーと負に帯電したモノマーからなるポリマー鎖(ポリアンフォーライト)のコイル(C)グロビュール(G)転移をモンテカルロシミュレーション(ボンド揺らぎモデル、BFM)を用いて考察したものである。先ず、BFMモデルを用いて正、負のモノマーが交互に並んだ場合(a-PA)について考察し、比熱などの異常性からCG転移が確認された。次いで、欠陥のあるPAおよびdiblock copolymerについてもモンテカルロシミュレーションを行い、a-PAとの相違について興味ある結果を得た。いづれの場合もa-PAとの場合と同様にCG転移が得られるが、特に興味あるのはdiblock copolymerの場合で、この場合にはCG転移が生じるよりも十分高い温度においても比熱などに異常性が得られる。これは鎖の中央付近を頂点にして2つにおりたたまられるモードに関連している(hairpin stateと呼ぶ)。2次元、3次元モデルのCG転移についても特徴的な相違が発見された。diblock copolymerのグロビュール状態は上の2つ折り状態(hairpin state)から発展・成長していくとかんがえられるからである。その際、局所的にフラストレートした状態が得られ、これを解消していく過程で2次元系では渦巻きの形態が得られる。これら2、3次元系固有の分子の高次構造の形成・転移の本性を明らかにするため、分子の平均の慣性半径、最近接距離、各種分布関数、自由エネルギーなどの計算を行った。また分子構造のダイナミックスについての知見を得るため2つの異なる温度について分子動力学(拘束法)シミュレーションを行った。特に高温の場合はhairpin stateが形成されていく過程が明瞭に観察された。

Research Products

(26 results)

All Other

All Publications (26 results)

[Publications] K.Uehara: "First-principle molecular dynamics calculation of selenium clusters" J.Mol.Simulation. 18. 385-394 (1997)
[Publications] K.Uehara: "First-principles molecular dynamics simulations for Se_8 and Se_8^+ clusters" J.Mol.Simulation,in press.
[Publications] S.Makino: "Classical Molecular Dynamics for the Formation Process of a Fullerene Molecule" J.Phys.Chem.Solids,in press.
[Publications] T.Hashimoto: "Structural Transformations of Ice at High Pressures via Molecular Dynamics Simulations" J.Mol.Simulation. 18. 115-132 (1996)
[Publications] T.Hashimoto: "Structural transformations of ice at normal and high pressures via molecular dynamicssimulations" Proc.PCI'96,in press.
[Publications] T.Hashimoto: "Structural transformation of oce at high pressures via molecular dynamics simulation II" J.Mol.Simulation. 18. 395-406 (1997)
[Publications] J.Habasaki: "Fracton Exciattion and Levy Flight Dynamics in Alkali Silicate Glasses" Phys.Rev.B,in press.
[Publications] J.Habasaki: "Relaxation processes and the mixed alkali effect in alkali metasilicate glasses" Proc.MRS Fall Meetings,in press.
[Publications] J.Habasaki: "MD study of the mixed alkali effect in terms of the potential surface in the lithium-potassium metasilicate glass" J.Non-Cryst,Solids,in press.
[Publications] J.Habasaki: "Mixed Alkali Effect in Alkali Metadilicate Glasses" Proceedings of YKIS96,in press.
[Publications] 巾崎潤子: "アルカリケイ酸塩ガラスの構造とダイナミックス-ガラス転移、緩和現象と混合アルカリ効果-" 高分子論文集. 53. 774-787 (1996)
[Publications] T.Muranaka: "Study on the β peak of χ^″ for a two-dimensional supercooled fluid state via molecular dynamics simulation" J.Mol.Simulation. 16. 387-397 (1996)
[Publications] T.Muranaka: "Coupling between Jump Motions and Correlated Motions" Proceedings of YKIS96,. (in press).
[Publications] 橋本保: "氷に関する最近の分子動力学シミュレーション-氷の構造相転移-" 日本雪氷学会誌雪氷. 58. 422-424 (1996)
[Publications] Y.Hiwatari: "Molecular-dynamics simulation for the formation process of a fullerene molecule" RIKEN Rev. 14. 7-8 (1996)
[Publications] K.Uehara: "First-principle molecular dynamics calculation of selenium clusters" Proceedings of the ISSPIC 8,. (in press).
[Publications] T.Odagaki: "Glass transition singularities and slow relaxation" Mat.Res.Soc.Symp.Proc.367. 337-346 (1995)
[Publications] Y.Hiwatari: "Slow Dynamics in Supercooled Fluids" J.Mol.Liquids. 65/66. 123-130 (1995)
[Publications] Y.Hiwatari: "Molecular-Dynamics Study of Supercooled Liquids and the Theory of the Glass Transition" J.Phys.Soc.Jpn.,Comp.Physics as a New Frontier in Condensed Matter Res.329-339 (1995)
[Publications] J.Habasaki: "MD study of the mixed alkali effect in a lithium-potassium metasilicate glass" J.Non-Crystalline Solids. 183. 12-21 (1995)
[Publications] T.Muranaka: "β relaxation in a highly supercooled state via molecular dynamics simulation" Phys.Rev.E51. R2735-R2738 (1995)
[Publications] J.Habasaki: "Origins of the two-step relaxation and the boson peak in an alkali silicate glass studied by molecular-dynamics simulation" Phys.Rev.E52. 2681-2687 (1995)
[Publications] J.B.Imbert: "Conformational Transitions of a Diblock Polyampholyte in 2 and 3 Dimensions" submitted to Europhysucs Letters.
[Publications] N.Urakami: "Multicanonical Monte Carlo Simulation of a Polymer with Stickers" J.Phys.Sci.of Japan. 65. 2694-2699 (1996)
[Publications] N.Urakami: "The distribution of the Gyration Radius of a Model of Ionomer Studied by Multicanonical Monte Carlo Simulation" Mol.Simylation. (in press).
[Publications] N.Urakami: "Monte-Carlo simulation of a polymer with stickers…Initial relaxation and free energy calculations…" Proceedings of YKIS96. (in press).

1996 Fiscal Year Annual Research Report

鎖状異種高分子(linear heteropolymers)の統計力学的研究

Principal Investigator

樋渡 保秋 金沢大学, 理学部, 教授 (20019491)

Research Products

[Publications] K.Uehara: "First-principle molecular dynamics calculation of selenium clusters" J.Mol.Simulation. 18. 385-394 (1997)

[Publications] K.Uehara: "First-principles molecular dynamics simulations for Se_8 and Se_8^+ clusters" J.Mol.Simulation,in press.

[Publications] S.Makino: "Classical Molecular Dynamics for the Formation Process of a Fullerene Molecule" J.Phys.Chem.Solids,in press.

[Publications] T.Hashimoto: "Structural Transformations of Ice at High Pressures via Molecular Dynamics Simulations" J.Mol.Simulation. 18. 115-132 (1996)

[Publications] T.Hashimoto: "Structural transformations of ice at normal and high pressures via molecular dynamicssimulations" Proc.PCI'96,in press.

[Publications] T.Hashimoto: "Structural transformation of oce at high pressures via molecular dynamics simulation II" J.Mol.Simulation. 18. 395-406 (1997)

[Publications] J.Habasaki: "Fracton Exciattion and Levy Flight Dynamics in Alkali Silicate Glasses" Phys.Rev.B,in press.

[Publications] J.Habasaki: "Relaxation processes and the mixed alkali effect in alkali metasilicate glasses" Proc.MRS Fall Meetings,in press.

[Publications] J.Habasaki: "MD study of the mixed alkali effect in terms of the potential surface in the lithium-potassium metasilicate glass" J.Non-Cryst,Solids,in press.

[Publications] J.Habasaki: "Mixed Alkali Effect in Alkali Metadilicate Glasses" Proceedings of YKIS96,in press.

[Publications] 巾崎潤子: "アルカリケイ酸塩ガラスの構造とダイナミックス-ガラス転移、緩和現象と混合アルカリ効果-" 高分子論文集. 53. 774-787 (1996)

[Publications] T.Muranaka: "Study on the β peak of χ^″ for a two-dimensional supercooled fluid state via molecular dynamics simulation" J.Mol.Simulation. 16. 387-397 (1996)

[Publications] T.Muranaka: "Coupling between Jump Motions and Correlated Motions" Proceedings of YKIS96,. (in press).

[Publications] 橋本保: "氷に関する最近の分子動力学シミュレーション-氷の構造相転移-" 日本雪氷学会誌雪氷. 58. 422-424 (1996)

[Publications] Y.Hiwatari: "Molecular-dynamics simulation for the formation process of a fullerene molecule" RIKEN Rev. 14. 7-8 (1996)

[Publications] K.Uehara: "First-principle molecular dynamics calculation of selenium clusters" Proceedings of the ISSPIC 8,. (in press).

[Publications] T.Odagaki: "Glass transition singularities and slow relaxation" Mat.Res.Soc.Symp.Proc.367. 337-346 (1995)

[Publications] Y.Hiwatari: "Slow Dynamics in Supercooled Fluids" J.Mol.Liquids. 65/66. 123-130 (1995)

[Publications] Y.Hiwatari: "Molecular-Dynamics Study of Supercooled Liquids and the Theory of the Glass Transition" J.Phys.Soc.Jpn.,Comp.Physics as a New Frontier in Condensed Matter Res.329-339 (1995)

[Publications] J.Habasaki: "MD study of the mixed alkali effect in a lithium-potassium metasilicate glass" J.Non-Crystalline Solids. 183. 12-21 (1995)

[Publications] T.Muranaka: "β relaxation in a highly supercooled state via molecular dynamics simulation" Phys.Rev.E51. R2735-R2738 (1995)

[Publications] J.Habasaki: "Origins of the two-step relaxation and the boson peak in an alkali silicate glass studied by molecular-dynamics simulation" Phys.Rev.E52. 2681-2687 (1995)

[Publications] J.B.Imbert: "Conformational Transitions of a Diblock Polyampholyte in 2 and 3 Dimensions" submitted to Europhysucs Letters.

[Publications] N.Urakami: "Multicanonical Monte Carlo Simulation of a Polymer with Stickers" J.Phys.Sci.of Japan. 65. 2694-2699 (1996)

[Publications] N.Urakami: "The distribution of the Gyration Radius of a Model of Ionomer Studied by Multicanonical Monte Carlo Simulation" Mol.Simylation. (in press).

[Publications] N.Urakami: "Monte-Carlo simulation of a polymer with stickers…Initial relaxation and free energy calculations…" Proceedings of YKIS96. (in press).

樋渡保秋金沢大学, 理学部, 教授 (20019491)