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Bae Y, Ha MY, Bang KT, Yang S, Kang SY, Kim J, Sung J, Kang S, Kang D, Lee WB, Choi TL, Park J. Conformation Dynamics of Single Polymer Strands in Solution. Adv Mater 2022; 34:e2202353. [PMID: 35725274 DOI: 10.1002/adma.202202353] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Conformational changes in macromolecules significantly affect their functions and assembly into high-level structures. Despite advances in theoretical and experimental studies, investigations into the intrinsic conformational variations and dynamic motions of single macromolecules remain challenging. Here, liquid-phase transmission electron microscopy enables the real-time tracking of single-chain polymers. Imaging linear polymers, synthetically dendronized with conjugated aromatic groups, in organic solvent confined within graphene liquid cells, directly exhibits chain-resolved conformational dynamics of individual semiflexible polymers. These experimental and theoretical analyses reveal that the dynamic conformational transitions of the single-chain polymer originate from the degree of intrachain interactions. In situ observations also show that such dynamics of the single-chain polymer are significantly affected by environmental factors, including surfaces and interfaces.
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Affiliation(s)
- Yuna Bae
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
| | - Min Young Ha
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Ki-Taek Bang
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sanghee Yang
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Yun Kang
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joodeok Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
| | - Jongbaek Sung
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
| | - Sungsu Kang
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
| | - Dohun Kang
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Won Bo Lee
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Tae-Lim Choi
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jungwon Park
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Institute of Engineering Research, Seoul National University, Seoul, 08826, Republic of Korea
- Advanced Institutes of Convergence Technology, Seoul National University, Suwon, Gyeonggi, 16229, Republic of Korea
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Benková Z, Rišpanová L, Cifra P. Conformation of Flexible and Semiflexible Chains Confined in Nanoposts Array of Various Geometries. Polymers (Basel) 2020; 12:E1064. [PMID: 32384748 PMCID: PMC7284769 DOI: 10.3390/polym12051064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 01/17/2023] Open
Abstract
The conformation and distribution of a flexible and semiflexible chain confined in an array of nanoposts arranged in parallel way in a square-lattice projection of their cross-section was investigated using coarse-grained molecular dynamics simulations. The geometry of the nanopost array was varied at the constant post diameter dp and the ensuing modifications of the chain conformation were compared with the structural behavior of the chain in the series of nanopost arrays with the constant post separation Sp as well as with the constant distance between two adjacent post walls (passage width) wp. The free energy arguments based on an approximation of the array of nanopost to a composite of quasi-channels of diameter dc and quasi-slits of height wp provide semiqualitative explanations for the observed structural behavior of both chains. At constant post separation and passage width, the occupation number displays a monotonic decrease with the increasing geometry ratio dc/wp or volume fraction of posts, while a maximum is observed at constant post diameter. The latter finding is attributed to a relaxed conformation of the chains at small dc/wp ratio, which results from a combination of wide interstitial volumes and wide passage apertures. This maximum is approximately positioned at the same dc/wp value for both flexible and semiflexible chains. The chain expansion from a single interstitial volume into more interstitial volumes also starts at the same value of dc/wp ratio for both chains. The dependence of the axial chain extension on the dc/wp ratio turns out to be controlled by the diameter of the interstitial space and by the number of monomers in the individual interstitial volumes. If these two factors act in the same way on the axial extension of chain fragments in interstitial volumes the monotonic increase of the axial chain extension with the dc/wp in the nanopost arrays is observed. At constant wp, however, these two factors act in opposite way and the axial chain extension plotted against the dc/wp ratio exhibits a maximum. In the case of constant post diameter, the characteristic hump in the single chain structure factor whose position correlates with the post separation is found only in the structure factor of the flexible chain confined in the nanopost array of certain value of Sp. The structure factor of the flexible chain contains more information on the monomer organization and mutual correlations than the structure factor of the semiflexible chain. The stiffer chain confined in the nanopost array is composed of low number of statistical segments important for the presence of respective hierarchical regimes in the structure factor.
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Affiliation(s)
- Zuzana Benková
- Polymer Institute, Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia; (L.R.); (P.C.)
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Abstract
We briefly review the recent developments in the theory of individual semiflexible filaments, and of a crosslinked network of such filaments, both permanent and transient. Starting from the free energy of an individual semiflexible chain, models on its force-extension relation and other mechanical properties such as Euler buckling are discussed. For a permanently crosslinked network of filaments, theories on how the network responds to deformation are provided, with a focus on continuum approaches. Characteristic features of filament networks, such as nonlinear stress-strain relation, negative normal stress, tensegrity, and marginal stability are discussed. In the new area of transient filament network, where the crosslinks can be dynamically broken and re-formed, we show some recent attempts for understanding the dynamics of the crosslinks, and the related rheological properties, such as stress relaxation, yield stress and plasticity.
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Affiliation(s)
- Fanlong Meng
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK.
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP, UK.
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