Tag: Imaging techniques

Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy

Real-space images of polymers with sub-molecular resolution could provide valuable insights into the relationship between morphology and functionality of polymer optoelectronic devices, but their acquisition is problematic due to perceived limitations in atomic force microscopy (AFM).*

In the article “Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy” Vladimir V. Korolkov, Alex Summerfield, Alanna Murphy, David B. Amabilino, Kenji Watanabe, Takashi Taniguchi and Peter H. Beton show that individual thiophene units and the lattice of semicrystalline spin-coated films of polythiophenes (PTs) may be resolved using AFM under ambient conditions through the low-amplitude (≤ 1 nm) excitation of higher eigenmodes of a cantilever.*

They authors demonstrate that the use of higher eigenmodes in tapping-mode ambient AFM can be successfully employed to characterize both individual polymer strands down to a single-atom level and also the ordering of a semi-crystalline polymer with technological relevance. The combination of AFM and solution deposition provides a simple and high-resolution approach to characterizing the structure of polymers.*

The use of NanoWorld Arrow-UHF high frequency AFM probes at their first eigenmode of ~1.4 MHz is mentioned.*


Figure 1a from “Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy” by V. Korolkov et al.: High-resolution AFM images of P3DT adsorbed on the surface of hBN. a An overview height scan of P3DT assembled on hBN, scan rate 6.51 Hz, 1024 × 1024 px; inset shows lattice frequency shift image of hBN acquired in FM-AFM tapping mode, scan rate 39 Hz, 512 × 512 px; both images were acquired with the same Arrow UHF probe oscillating at fundamental frequency of 1.42 MHz.

*Vladimir V. Korolkov, Alex Summerfield, Alanna Murphy, David B. Amabilino, Kenji Watanabe, Takashi Taniguchi and Peter H. Beton
Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy
Nature Communications, volume 10, Article number: 1537 (2019)
doi: https://doi.org/10.1038/s41467-019-09571-6

Please follow this external link to read the full article: https://rdcu.be/bLSdL

Open Access: The article « Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy » by Vladimir V. Korolkov, Alex Summerfield, Alanna Murphy, David B. Amabilino, Kenji Watanabe, Takashi Taniguchi and Peter H. Beton is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Direct Observation of Long-Chain Branches in a Low-Density Polyethylene

The properties of a polymer change significantly depending on the structure of the polymer chain, particularly, with branched structures, depending on the number of branches and the length of the branch.* However, the long-chain branch (LCB) structure of polyethylene was unclear, due particularly to the complex polymer structure and the limitations of its analysis methods.

In their study “Direct Observation of Long-Chain Branches in a Low-Density Polyethylene” Ken-ichi Shinohara, Masahiro Yanagisawa and Yuu Makida measured the chain length of LCBs and the distance between branch points of LDPE by atomic force microscopy.*

The article mentions the use of NanoWorld Ultra-Short Cantilevers (USC) for high speed atomic force microscopy ( AFM probe type USC-F1.2-k0.15 ) for the single-molecule imaging by atomic force microscopy .*

Figure 1 from “Direct Observation of Long-Chain Branches in a Low-Density Polyethylene “ by K. Shinohara et al.: Direct measurement of LCB in a tubular LDPE (F200-0 fractionated). (A) AFM image of a single molecule of LDPE on mica in DMTS at 25 °C. X: 279 nm, Y: 209 nm, Z: 18 nm. (B) Length of each chain of LDPE. (C) A wire model of self-shrinking structure of polymer chain of LDPE. Main chain: red wire. LCB: black wire. The model was created to be one tenth of the length of the extended chain based on AFM observation (B), MD simulation (Fig. S1), and the molecular weight determined by SEC-MALLS-Visc experiments (see Fig. 2).
Figure 1 from “Direct Observation of Long-Chain Branches in a Low-Density Polyethylene “ by K. Shinohara et al.: Direct measurement of LCB in a tubular LDPE (F200-0 fractionated). (A) AFM image of a single molecule of LDPE on mica in DMTS at 25 °C. X: 279 nm, Y: 209 nm, Z: 18 nm. (B) Length of each chain of LDPE. (C) A wire model of self-shrinking structure of polymer chain of LDPE. Main chain: red wire. LCB: black wire. The model was created to be one tenth of the length of the extended chain based on AFM observation (B), MD simulation (Fig. S1), and the molecular weight determined by SEC-MALLS-Visc experiments (see Fig. 2).

*Ken-ichi Shinohara, Masahiro Yanagisawa, Yuu Makida
Direct Observation of Long-Chain Branches in a Low-Density Polyethylene
Nature Scientific Reportsvolume 9, Article number: 9791 (2019)
doi: https://doi.org/10.1038/s41598-019-46035-9

Please follow this external link for the full article: https://rdcu.be/bJY7S

Open Access: The article «Direct Observation of Long-Chain Branches in a Low-Density Polyethylene» by Ken-ichi Shinohara, Masahiro Yanagisawa and Yuu Makida is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Direct observation of dynamic interaction between a functional group in a single SBR chain and an inorganic matter surface

In the article  “Direct observation of dynamic interaction between a functional group in a single SBR chain and an inorganic matter surface” Ken-ichi Shinohara and Yuu Makida use atomic force microscopy (AFM) video imaging to closely investigate the behaviour of functionalized and unmodified styrene-butadiene rubber (SBR), as models for tire rubber, on mica surfaces.

“Using AFM video imaging, we tracked the behavior of individual SBR polymer chains on mica surfaces to reveal how polymer modification affects the interaction of SBR with mica surfaces. We measured the diffusion coefficients and spring constants of single SBR polymer chains for the first time, demonstrating that it is possible to parameterize the relationship between the molecular dynamic structure of a polymer and rubber properties of the vulcanized compound.”*

NanoWorld Ultra-Short Cantilevers (USC) for Fast-/High-Speed AFM  ( USC-F1.2-k0.15 ) were used

Figure 3 from “Direct observation of dynamic interaction between a functional group in a single SBR chain and an inorganic matter surface” by Ken-ichi Shinohara & Yuu Makida: (A) Single-molecule imaging of the structure of two isolated polymer chains of carboxyl-functionalized styrene-butadiene rubber (SBR) on mica under n-octylbenzene at 25 ± 1 °C (Movie S5). Snapshot AFM image of a fast-scanning atomic force microscopy (AFM) movie; X: 200 nm, Y: 150 nm, Z: 7.2 nm. Rate: 5.0 fps. (B) A snapshot of all-atom MD simulated structure of a single chain of carboxyl-functionalized SBR (CPK model) in n-octylbenzene as a solvent. Dynamic globular (ball-like) structures were formed partially in a SBR chain. The position of carboxyl group was indicated by an arrow. The backbone was displayed in purple. Solvent molecules are indicated by line model and hydrogen atoms are omitted for simplified to view. NanoWorld USC-F1.2-k0.15 AFM probes were used
Figure 3 from “Direct observation of dynamic interaction between a functional group in a single SBR chain and an inorganic matter surface” by Ken-ichi Shinohara & Yuu Makida: (A) Single-molecule imaging of the structure of two isolated polymer chains of carboxyl-functionalized styrene-butadiene rubber (SBR) on mica under n-octylbenzene at 25 ± 1 °C (Movie S5). Snapshot AFM image of a fast-scanning atomic force microscopy (AFM) movie; X: 200 nm, Y: 150 nm, Z: 7.2 nm. Rate: 5.0 fps. (B) A snapshot of all-atom MD simulated structure of a single chain of carboxyl-functionalized SBR (CPK model) in n-octylbenzene as a solvent. Dynamic globular (ball-like) structures were formed partially in a SBR chain. The position of carboxyl group was indicated by an arrow. The backbone was displayed in purple. Solvent molecules are indicated by line model and hydrogen atoms are omitted for simplified to view.

*Ken-ichi Shinohara & Yuu Makida
Direct observation of dynamic interaction between a functional group in a single SBR chain and an inorganic matter surface
Nature Scientific Reports, volume 8, Article number: 13982 (2018)
DOI: https://doi.org/10.1038/s41598-018-32382-6

For the full article please follow this external link: https://rdcu.be/bbERH

The article “Direct observation of dynamic interaction between a functional group in a single SBR chain and an inorganic matter surface” by Ken-ichi Shinohara & Yuu Makida is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.