Single-Molecule Imaging of Structural Dynamics of a Polymer Chain and Interactions between Polymer Chains

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02546
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 28010:Nanometer-scale chemistry-related
• Research Institution: Japan Advanced Institute of Science and Technology
• Principal Investigator: Shinohara Ken-ichi 北陸先端科学技術大学院大学, 先端科学技術研究科, 准教授 (10292244)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ポリマー / １分子 / AFM / 高速AFM / 分子マシン / 分子モーター / キラル高分子 / 機能性高分子

Outline of Final Research Achievements

Anionic and cationic polymer chains are thought to be attracted by electrostatic interactions. From what distance do the chains feel their attraction to each other and join together? We first clarified this by direct observation by high-speed AFM imaging. PAMPS and PAMPS sodium salt were used as anionic polymers, while polyallylamine (PAA) and PAA hydrochloride were employed as cationic polymers. Since it is necessary to distinguish between the two by high-speed AFM, one having a significantly different molecular weight was used. Since it is possible to interact between the sulfonic acid group of PAMPS and the amide group of PAA, as a result of elucidating this dynamics, a complex in which one PAA short chain molecule is bound to the end of one PAMPS long chain was confirmed.

Free Research Field

高分子化学

Academic Significance and Societal Importance of the Research Achievements

分子間相互作用には、ファンデルワールス相互作用、静電相互作用、水素結合による相互作用、水中における疎水性相互作用などがある。本研究では、これらの相互作用がポリマーの分子内（鎖中）および分子間（鎖間）でどう働き、どのような構造とダイナミクスが観測されるかを明らかにした。
その結果、ポリマー鎖一本同士の相互作用が高速AFMで直接確認された。これは、分子マシンの創製に必須の知見であり、将来実現されるであろう分子モーターに繋がる成果である。