1
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Sunazuka Y, Ueda K, Higashi K, Wada K, Moribe K. Mechanistic Analysis of Temperature-Dependent Curcumin Release from Poly(lactic-co-glycolic acid)/Poly(lactic acid) Polymer Nanoparticles. Mol Pharm 2024; 21:1424-1435. [PMID: 38324797 DOI: 10.1021/acs.molpharmaceut.3c01066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
In this study, we investigated the mechanism of curcumin (CUR) release from poly(lactic-co-glycolic acid) (PLGA) and poly(lactic acid) (PLA) nanoparticles (NPs) by evaluating the temperature-dependent CUR release. NPs were prepared by the nanoprecipitation method using various PLGA/PLA polymers with different lactic:glycolic ratios (L:G ratios) and molecular weights. Increasing the polymer molecular weight resulted in a decrease in the particle size of NPs. The wet glass transition temperature (Tg) of PLGA/PLA NPs was lower than the intrinsic polymer Tg, which can be derived from the water absorption and nanosizing of the polymer. The reduction in Tg was more significant for the PLGA/PLA NPs with lower polymer L:G ratios and lower polymer molecular weight. The greater decrease of Tg in the lower polymer L:G ratios was possibly caused by the higher water absorption due to the more hydrophilic nature of the glycolic acid segment than that of the lactic acid segment. The efficient water absorption in PLGA/PLA NPs with lower molecular weight could cause a significant reduction of Tg as it has lower hydrophobicity. CUR release tests from the PLGA/PLA NPs exhibited enhanced CUR release with increasing temperatures, irrespective of polymer species. By fitting the CUR release profiles into mathematical models, the CUR release process was well described by an initial burst release followed by a diffusion-controlled release. The wet Tg and particle size of the PLGA/PLA NPs affected the amount and temperature dependence of the initial burst release of CUR. Above the wet Tg of NPs, the initial burst release of CUR increased sharply. Smaller particle sizes of PLGA/PLA NPs led to a higher fraction of initial CUR burst release, which was more pronounced above the wet Tg of NPs. The wet Tg and particle sizes of the PLGA/PLA NPs also influenced the diffusion-controlled CUR release. The diffusion rate of CUR in the NPs increased as the wet Tg values of the NPs decreased. The diffusion path length of CUR was affected by the particle size, with larger particle size resulting in a prolonged diffusion-controlled release of CUR. This study highlighted that for the formulation development of PLGA/PLA NPs, suitable PLGA/PLA polymers should be selected considering the physicochemical properties of PLGA/PLA NPs and their correlation with the release behavior of encapsulated drugs at the application temperature.
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Affiliation(s)
- Yushi Sunazuka
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
- Nippon Boehringer Ingelheim Co. Ltd., 6-7-5 Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Keisuke Ueda
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Kenjirou Higashi
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Koichi Wada
- Nippon Boehringer Ingelheim Co. Ltd., 6-7-5 Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Kunikazu Moribe
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
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2
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Gross N, Kuhs CT, Ostovar B, Chiang WY, Wilson KS, Volek TS, Faitz ZM, Carlin CC, Dionne JA, Zanni MT, Gruebele M, Roberts ST, Link S, Landes CF. Progress and Prospects in Optical Ultrafast Microscopy in the Visible Spectral Region: Transient Absorption and Two-Dimensional Microscopy. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:14557-14586. [PMID: 37554548 PMCID: PMC10406104 DOI: 10.1021/acs.jpcc.3c02091] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/24/2023] [Indexed: 08/10/2023]
Abstract
Ultrafast optical microscopy, generally employed by incorporating ultrafast laser pulses into microscopes, can provide spatially resolved mechanistic insight into scientific problems ranging from hot carrier dynamics to biological imaging. This Review discusses the progress in different ultrafast microscopy techniques, with a focus on transient absorption and two-dimensional microscopy. We review the underlying principles of these techniques and discuss their respective advantages and applicability to different scientific questions. We also examine in detail how instrument parameters such as sensitivity, laser power, and temporal and spatial resolution must be addressed. Finally, we comment on future developments and emerging opportunities in the field of ultrafast microscopy.
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Affiliation(s)
- Niklas Gross
- Department
of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Christopher T. Kuhs
- Army
Research Laboratory-South, U.S. Army DEVCOM, Houston, Texas 77005, United States
| | - Behnaz Ostovar
- Department
of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Wei-Yi Chiang
- Department
of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Kelly S. Wilson
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Tanner S. Volek
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Zachary M. Faitz
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Claire C. Carlin
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
| | - Jennifer A. Dionne
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
- Department
of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, California 94305, United States
| | - Martin T. Zanni
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Martin Gruebele
- Department
of Chemistry, University of Illinois at
Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Physics, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Center
for Biophysics and Quantitative Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Sean T. Roberts
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Stephan Link
- Department
of Chemistry, Rice University, Houston, Texas 77005, United States
- Department
of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department
of Chemistry, Rice University, Houston, Texas 77005, United States
- Department
of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
- Department
of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
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3
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Joung H, Kim C, Yu J, Lee S, Paeng K, Yang J. Impact of Chain Conformation on Structural Heterogeneity in Polymer Network. NANO LETTERS 2022; 22:5487-5494. [PMID: 35748615 DOI: 10.1021/acs.nanolett.2c01574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Polymer networks generally consist of an ensemble of single chains. However, understanding how chain conformation affects the structure and properties of polymer networks remains a challenge for optimizing their functionality. Here, we present the fabrication and comparative study of a polymer network composed of collapsed self-entangled chains (intrachain entangled network) and a standard polymer network in which random-coil chains are entangled with each other (interchain entangled network). For poly(methyl methacrylate) thin films composed of these networks, we coupled solvent vapor swelling and single-molecule tracking techniques to examine the anomalies in the dynamics of a small-molecular probe included in the system. We demonstrate that when compared to the interchain entangled network the intrachain one exhibits a more substantial structural heterogeneity, particularly under highly crowded conditions. This network also exhibits physical compactness, which keeps the heterogeneous network structure frozen over time and impedes network plasticization through solvent uptake by the film.
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Affiliation(s)
- Hyeyoung Joung
- Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Korea
| | - Chanwoo Kim
- Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Korea
| | - Jaesang Yu
- Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Korea
| | - Soohyun Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
| | - Keewook Paeng
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
| | - Jaesung Yang
- Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Korea
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4
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Xing Z, Zhu N, Yang Y, Wang X, Zuo B. Alternating chain sequence weakening of interfacial molecular interactions enhances the Tg confinement effect of polymers. Polym J 2022. [DOI: 10.1038/s41428-022-00672-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Single molecule demonstration of Debye-Stokes-Einstein breakdown in polystyrene near the glass transition temperature. Nat Commun 2022; 13:3580. [PMID: 35739122 PMCID: PMC9226357 DOI: 10.1038/s41467-022-31318-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/10/2022] [Indexed: 11/25/2022] Open
Abstract
Rotational-translational decoupling, in which translational motion is apparently enhanced over rotational motion in violation of Stokes-Einstein (SE) and Debye-Stokes-Einstein (DSE) predictions, has been observed in materials near their glass transition temperatures (Tg). This has been posited to result from ensemble averaging in the context of dynamic heterogeneity. In this work, ensemble and single molecule experiments are performed in parallel on a fluorescent probe in high molecular weight polystyrene near its Tg. Ensemble results show decoupling onset at approximately 1.15Tg, increasing to over three orders of magnitude at Tg. Single molecule measurements also show a high degree of decoupling, with typical molecules at Tg showing translational diffusion coefficients nearly 400 times higher than expected from SE/DSE predictions. At the single molecule level, higher degree of breakdown is associated with particularly mobile molecules and anisotropic trajectories, providing support for anomalous diffusion as a critical driver of rotational-translational decoupling and SE/DSE breakdown. Experiments with high-molecular-weight polystyrene provide insights into the mechanisms behind rotational-translational decoupling in glassy systems. Specifically, particularly mobile molecules exhibiting anisotropic trajectories are found to play a key role in Debye-Stokes-Einstein breakdown.
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6
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Saluga SJ, Dibble DJ, Blum SA. Superresolved Motions of Single Molecular Catalysts during Polymerization Show Wide Distributions. J Am Chem Soc 2022; 144:10591-10598. [PMID: 35670469 DOI: 10.1021/jacs.2c03566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The motion of single molecular ruthenium catalysts during and after single turnover events of ring-opening metathesis polymerization is imaged through single-molecule superresolution tracking with a positional accuracy of ±32 nm. This tracking is achieved through the real-time incorporation of spectrally tagged monomer units into active polymer chain ends during living polymerization; thus, by design, only active-catalyst motion is detected and imaged, without convolution by inactive catalysts. The catalysts show diverse individualistic diffusive behaviors with respect to time that persist for up to 20 s. Catalysts occupy three mobility populations: quasi-stationary (23%), intermediate (53%, 65 nm), and large (24%, 145 nm) step sizes. Differences in catalyst mobility populations also exist between individual aggregates (p < 0.001). Such differential motion indicates widely different local catalyst microenvironments during the catalytic turnover. These mobility differences are uniquely observable through single-catalyst microscopy and are not measurable through traditional ensemble analytical techniques for characterizing the behavior of molecular catalysts, such as nuclear magnetic resonance spectroscopy. The measured distributions of active molecular catalyst motions would not be readily predictable through modeling or first-principles, and the range likely impacts individual catalyst turnover rate and selectivity. This range plausibly contributes to property distributions observable in bulk polymers, such as molecular weight polydispersity (e.g., 1.9 in this system), leading to a revised understanding of the mechanistic, microscale origins of macroscale polymer properties.
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Affiliation(s)
- Shannon J Saluga
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - David Josh Dibble
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Suzanne A Blum
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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7
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Adhikari S, Orrit M. Progress and perspectives in single-molecule optical spectroscopy. J Chem Phys 2022; 156:160903. [PMID: 35489995 DOI: 10.1063/5.0087003] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We review some of the progress of single-molecule optical experiments in the past 20 years and propose some perspectives for the coming years. We particularly focus on methodological advances in fluorescence, super-resolution, photothermal contrast, and interferometric scattering and briefly discuss a few of the applications. These advances have enabled the exploration of new emitters and quantum optics; the chemistry and biology of complex heterogeneous systems, nanoparticles, and plasmonics; and the detection and study of non-fluorescing and non-absorbing nano-objects. We conclude by proposing some ideas for future experiments. The field will move toward more and better signals of a broader variety of objects and toward a sharper view of the surprising complexity of the nanoscale world of single (bio-)molecules, nanoparticles, and their nano-environments.
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Affiliation(s)
- Subhasis Adhikari
- Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2333 CA Leiden, The Netherlands
| | - Michel Orrit
- Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2333 CA Leiden, The Netherlands
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8
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Ge S, Wang E, Li J, Tang BZ. Aggregation-Induced Emission Boosting the Study of Polymer Science. Macromol Rapid Commun 2022; 43:e2200080. [PMID: 35320607 DOI: 10.1002/marc.202200080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/09/2022] [Indexed: 11/07/2022]
Abstract
The past one hundred years witness the great development of polymer science. The advancement of polymer science is closely related with the developing of characterization techniques and methods, from viscometry in molecular weight determination to advanced techniques including differential scanning calorimetry, nuclear magnetic resonance and scanning electron microscopy. However, these techniques are normally constrained to tedious sample preparation, high cost, harsh experimental condition, or ex-situ characterization. Fluorescence technology has the merits of high sensitivity and direct visualization. Contrary to conventional aggregation-causing quenching fluorophores, those dyes with aggregation-induced emission characteristic show high emission efficiency in aggregate states. Based on the restriction of intramolecular motions for AIE properties, the AIE materials are very sensitive to the surrounding microenvironments owing to the twisted propeller-like structures and therefore reveal great potentials in polymer's study. The AIE concept has been successfully used in polymer's study and provides us a deeper understanding on polymer structure and properties. In this review, the applications of AIEgens in polymer science for visualizing polymerization, glass transition, dissolution, crystallization, gelation, self-assembly, phase separation, cracking and self-healing were exemplified and summarized. Lastly, the challenges and perspectives in the study of polymer science using AIEgens are addressed. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Sheng Ge
- S. Ge, Dr. E. Wang, Prof. J. Li, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan, 430062, China
| | - Erjing Wang
- S. Ge, Dr. E. Wang, Prof. J. Li, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan, 430062, China
| | - Jinhua Li
- S. Ge, Dr. E. Wang, Prof. J. Li, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang District, Wuhan, 430062, China
| | - Ben Zhong Tang
- Prof. B. Z. Tang, Shenzhen Institute of Aggregate Science and Technology, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, No. 2001 Longxiang Boulevard, Longgang District, Shenzhen, Guangdong, 518172, China
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9
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10
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Doerries TJ, Chechkin AV, Schumer R, Metzler R. Rate equations, spatial moments, and concentration profiles for mobile-immobile models with power-law and mixed waiting time distributions. Phys Rev E 2022; 105:014105. [PMID: 35193292 DOI: 10.1103/physreve.105.014105] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
We present a framework for systems in which diffusion-advection transport of a tracer substance in a mobile zone is interrupted by trapping in an immobile zone. Our model unifies different model approaches based on distributed-order diffusion equations, exciton diffusion rate models, and random-walk models for multirate mobile-immobile mass transport. We study various forms for the trapping time dynamics and their effects on the tracer mass in the mobile zone. Moreover, we find the associated breakthrough curves, the tracer density at a fixed point in space as a function of time, and the mobile and immobile concentration profiles and the respective moments of the transport. Specifically, we derive explicit forms for the anomalous transport dynamics and an asymptotic power-law decay of the mobile mass for a Mittag-Leffler trapping time distribution. In our analysis we point out that even for exponential trapping time densities, transient anomalous transport is observed. Our results have direct applications in geophysical contexts, but also in biological, soft matter, and solid state systems.
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Affiliation(s)
- Timo J Doerries
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
| | - Aleksei V Chechkin
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
- Faculty of Pure and Applied Mathematica, Hugo Steinhaus Center, Wrocław University of Science and Technology, Wyspianskiego 27, 50-370 Wrocław, Poland
- Akhiezer Institute for Theoretical Physics, 61108 Kharkov, Ukraine
| | - Rina Schumer
- Desert Research Institute, Reno, Nevada 89512, USA
| | - Ralf Metzler
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
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11
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Sorichetti V, Hugouvieux V, Kob W. Dynamics of Nanoparticles in Polydisperse Polymer Networks: from Free Diffusion to Hopping. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01394] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Valerio Sorichetti
- Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS), CNRS, Université Paris-Saclay, F-91405 Orsay, France
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, F-34095 Montpellier, France
- IATE, Université Montpellier, INRAE, Institut Agro, F-34060 Montpellier, France
| | - Virginie Hugouvieux
- IATE, Université Montpellier, INRAE, Institut Agro, F-34060 Montpellier, France
| | - Walter Kob
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, F-34095 Montpellier, France
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12
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Goto Y, Omagari S, Sato R, Yamakado T, Achiwa R, Dey N, Suga K, Vacha M, Saito S. Dynamic Polymer Free Volume Monitored by Single-Molecule Spectroscopy of a Dual Fluorescent Flapping Dopant. J Am Chem Soc 2021; 143:14306-14313. [PMID: 34448563 DOI: 10.1021/jacs.1c06428] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Single-molecule spectroscopy (SMS) of a dual fluorescent flapping molecular probe (N-FLAP) enabled real-time nanoscale monitoring of local free volume dynamics in polystyrenes. The SMS study was realized by structural improvement of a previously reported flapping molecule by nitrogen substitution, leading to increased brightness (22 times) of the probe. In a polystyrene thin film at the temperature of 5 K above the glass transition, the spectra of a single N-FLAP molecule undergo frequent jumps between short- and long-wavelength forms, the latter one indicating planarization of the molecule in the excited state. The observed spectral jumps were statistically analyzed to reveal the dynamics of the molecular environment. The analysis together with MD and QM/MM calculations show that the excited-state planarization of the flapping probe occurs only when sufficiently large polymer free volume of more than, at least, 280 Å3 is available close to the molecule, and that such free volume lasts for an average of 1.2 s.
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Affiliation(s)
- Yuma Goto
- Department of Materials Science and Engineering, School of Materials and Chemical Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-S8-44, Meguro-ku, Tokyo 152-8552, Japan
| | - Shun Omagari
- Department of Materials Science and Engineering, School of Materials and Chemical Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-S8-44, Meguro-ku, Tokyo 152-8552, Japan
| | - Ryuma Sato
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-3-26 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Takuya Yamakado
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Ryo Achiwa
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Nilanjan Dey
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kensuke Suga
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Martin Vacha
- Department of Materials Science and Engineering, School of Materials and Chemical Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-S8-44, Meguro-ku, Tokyo 152-8552, Japan
| | - Shohei Saito
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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13
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Nile R, Rajput H, Sims C, Jin K. Sensing the melting transition of semicrystalline polymers via a novel fluorescence technique. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.124070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Hao Z, Ghanekarade A, Zhu N, Randazzo K, Kawaguchi D, Tanaka K, Wang X, Simmons DS, Priestley RD, Zuo B. Mobility gradients yield rubbery surfaces on top of polymer glasses. Nature 2021; 596:372-376. [PMID: 34408328 DOI: 10.1038/s41586-021-03733-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 06/15/2021] [Indexed: 02/07/2023]
Abstract
Many emerging materials, such as ultrastable glasses1,2 of interest for phone displays and OLED television screens, owe their properties to a gradient of enhanced mobility at the surface of glass-forming liquids. The discovery of this surface mobility enhancement3-5 has reshaped our understanding of the behaviour of glass formers and of how to fashion them into improved materials. In polymeric glasses, these interfacial modifications are complicated by the existence of a second length scale-the size of the polymer chain-as well as the length scale of the interfacial mobility gradient6-9. Here we present simulations, theory and time-resolved surface nano-creep experiments to reveal that this two-scale nature of glassy polymer surfaces drives the emergence of a transient rubbery, entangled-like surface behaviour even in polymers comprised of short, subentangled chains. We find that this effect emerges from superposed gradients in segmental dynamics and chain conformational statistics. The lifetime of this rubbery behaviour, which will have broad implications in constraining surface relaxations central to applications including tribology, adhesion, and surface healing of polymeric glasses, extends as the material is cooled. The surface layers suffer a general breakdown in time-temperature superposition (TTS), a fundamental tenet of polymer physics and rheology. This finding may require a reevaluation of strategies for the prediction of long-time properties in polymeric glasses with high interfacial areas. We expect that this interfacial transient elastomer effect and TTS breakdown should normally occur in macromolecular systems ranging from nanocomposites to thin films, where interfaces dominate material properties5,10.
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Affiliation(s)
- Zhiwei Hao
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China
| | - Asieh Ghanekarade
- Department of Chemical, Biological, and Materials Engineering, University of South Florida, Tampa, FL, USA
| | - Ningtao Zhu
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China
| | - Katelyn Randazzo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - Daisuke Kawaguchi
- Department of Applied Chemistry, Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry, Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka, Japan
| | - Xinping Wang
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China
| | - David S Simmons
- Department of Chemical, Biological, and Materials Engineering, University of South Florida, Tampa, FL, USA.
| | - Rodney D Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA. .,Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, NJ, USA.
| | - Biao Zuo
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China.
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15
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Mahato J, Bhattacharya S, Sharma DK, Chowdhury A. Polarization-resolved single-molecule tracking reveals strange dynamics of fluorescent tracers through a deep rubbery polymer network. Phys Chem Chem Phys 2021; 23:10835-10844. [PMID: 33908423 DOI: 10.1039/d0cp05864e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Tracking the movement of fluorescent single-molecule (SM) tracers has provided several new insights into the local structure and dynamics in complex environments such as soft materials and biological systems. However, SM tracking (SMT) remains unreliable at molecular length scales, as the localization error (LE) of SM trajectories (∼30-50 nm) is considerably larger than the size of molecular tracers (∼1-2 nm). Thus, instances of tracer (im)mobility in heterogeneous media, which provide indicators for underlying anomalous-transport mechanisms, remain obscured within the realms of SMT. Since the translation of passive tracers in an isotropic media is associated with fast dipolar rotation, we propose that authentic pauses within the LE can be revealed by probing the hindrance of SM reorientational dynamics. Here, we demonstrate how polarization-resolved SMT (PR-SMT) can provide emission anisotropy at each super-localized position, thereby revealing the tumbling propensity of SMs during random walks. For rhodamine 6G tracers undergoing heterogeneous transport in a hydrated polyvinylpyrrolidone (PVP) network, analysis of PR-SMT trajectories enabled us to discern instances of genuine immobility and localized motion within the LE. Our investigations on 100 SMs in (plasticized) PVP films reveal a wide distribution of dwell times and pause frequencies, demonstrating that most probes intermittently experience complete translational and rotational immobilization. This indicates that tracers serendipitously encounter compact, rigid polymer cavities during transport, implying the existence of nanoscale glass-like domains sparsely distributed in a predominantly deep-rubbery polymer network far above the glass transition.
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Affiliation(s)
- Jaladhar Mahato
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Sukanya Bhattacharya
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Dharmendar K Sharma
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Arindam Chowdhury
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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16
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Zhang G, Rocha S, Lu G, Yuan H, Uji-i H, Floudas GA, Müllen K, Xiao L, Hofkens J, Debroye E. Spatially and Temporally Resolved Heterogeneities in a Miscible Polymer Blend. ACS OMEGA 2020; 5:23931-23939. [PMID: 32984713 PMCID: PMC7513360 DOI: 10.1021/acsomega.0c03173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
Mapping the spatial and temporal heterogeneities in miscible polymer blends is critical for understanding and further improving their material properties. However, a complete picture on the heterogeneous dynamics is often obscured in ensemble measurements. Herein, the spatial and temporal heterogeneities in fully miscible polystyrene/oligostyrene blend films are investigated by monitoring the rotational diffusion of embedded individual probe molecules using defocused wide-field fluorescence microscopy. In the same blend film, three significantly different types of dynamical behaviors (referred to as modes) of the probe molecules can be observed at the same time, namely, immobile, continuously rotating, and intermittently rotating probe molecules. This reveals a prominent spatial heterogeneity in local dynamics at the nanometer scale. In addition to that, temporal heterogeneity is uncovered by the nonexponential characteristic of the rotational autocorrelation functions of single-molecule probes. Moreover, the occurrence probabilities of these different modes strongly depend on the polystyrene: oligostyrene ratios in the blend films. Remarkably, some probe molecules switch between the continuous and intermittent rotational modes at elevated temperature, indicating a possible alteration in local dynamics that is triggered by the dynamic heterogeneity in the blends. Although some of these findings can be discussed by the self-concentration model and the results provided by ensemble averaging techniques (e.g., dielectric spectroscopy), there are implications that go beyond current models of blend dynamics.
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Affiliation(s)
- Guofeng Zhang
- State
Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute
of Laser Spectroscopy, Collaborative Innovation Center of Extreme
Optics, Shanxi University, Taiyuan, 030006, China
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - Susana Rocha
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - Gang Lu
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
- Institute
of Advanced Materials & Key Laboratory of Flexible Electronics, Nanjing Tech University, Nanjing 211816, China
| | - Haifeng Yuan
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
| | - Hiroshi Uji-i
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
- Research
Institute for Electronic Science (RIES), Hokkaido University, N20W10, Sapporo City 001-0020, Japan
| | - George A. Floudas
- Department
of Physics, University of Ioannina, GR-45110 Ioannina, Greece
- Max
Plank Institute for Polymer Research, Mainz D-55128, Germany
| | - Klaus Müllen
- Max
Plank Institute for Polymer Research, Mainz D-55128, Germany
| | - Liantuan Xiao
- State
Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute
of Laser Spectroscopy, Collaborative Innovation Center of Extreme
Optics, Shanxi University, Taiyuan, 030006, China
| | - Johan Hofkens
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
- Max
Plank Institute for Polymer Research, Mainz D-55128, Germany
| | - Elke Debroye
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
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17
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Cho HW, Kim H, Sung BJ, Kim JS. Tracer Diffusion in Tightly-Meshed Homogeneous Polymer Networks: A Brownian Dynamics Simulation Study. Polymers (Basel) 2020; 12:E2067. [PMID: 32932910 PMCID: PMC7569880 DOI: 10.3390/polym12092067] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 12/02/2022] Open
Abstract
We report Brownian dynamics simulations of tracer diffusion in regularly crosslinked polymer networks in order to elucidate the transport of a tracer particle in polymer networks. The average mesh size of homogeneous polymer networks is varied by assuming different degrees of crosslinking or swelling, and the size of a tracer particle is comparable to the average mesh size. Simulation results show subdiffusion of a tracer particle at intermediate time scales and normal diffusion at long times. In particular, the duration of subdiffusion is significantly prolonged as the average mesh size decreases with increasing degree of crosslinking, for which long-time diffusion occurs via the hopping processes of a tracer particle after undergoing rattling motions within a cage of the network mesh for an extended period of time. On the other hand, the cage dynamics and hopping process are less pronounced as the mesh size decreases with increasing polymer volume fractions. The interpretation is provided in terms of fluctuations in network mesh size: at higher polymer volume fractions, the network fluctuations are large enough to allow for collective, structural changes of network meshes, so that a tracer particle can escape from the cage, whereas, at lower volume fractions, the fluctuations are so small that a tracer particle remains trapped within the cage for a significant period of time before making infrequent jumps out of the cage. This work suggests that fluctuation in mesh size, as well as average mesh size itself, plays an important role in determining the dynamics of molecules and nanoparticles that are embedded in tightly meshed polymer networks.
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Affiliation(s)
- Hyun Woo Cho
- Department of Chemistry, Sogang University, Seoul 04107, Korea;
| | - Haein Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Korea;
| | - Bong June Sung
- Department of Chemistry, Sogang University, Seoul 04107, Korea;
| | - Jun Soo Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Korea;
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18
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Roberts TD, Yuan R, Xiang L, Delor M, Pokhrel R, Yang K, Aqad E, Marangoni T, Trefonas P, Xu K, Ginsberg NS. Direct Correlation of Single-Particle Motion to Amorphous Microstructural Components of Semicrystalline Poly(ethylene oxide) Electrolytic Films. J Phys Chem Lett 2020; 11:4849-4858. [PMID: 32510954 DOI: 10.1021/acs.jpclett.0c01318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Semicrystalline polymers constitute some of the most widely used materials in the world, and their functional properties are intimately connected to their structure on a range of length scales. Many of these properties depend on the micro- and nanoscale heterogeneous distribution of crystalline and amorphous phases, but this renders the interpretation of ensemble averaged measurements challenging. We use superlocalized widefield single-particle tracking in conjunction with AFM phase imaging to correlate the crystalline morphology of lithium-triflate-doped poly(ethylene oxide) thin films to the motion of individual fluorescent probes at the nanoscale. The results demonstrate that probe motion is intrinsically isotropic in amorphous regions and that, without altering this intrinsic diffusivity, closely spaced, often parallel, crystallite fibers anisotropically constrain probe motion along intercalating amorphous channels. This constraint is emphasized by the agreement between crystallite and anisotropic probe trajectory orientations. This constraint is also emphasized by the extent of the trajectory confinement correlated to the width of the measured gaps between adjacent crystallites. This study illustrates with direct nanoscale correlations how controlled and periodic arrangement of crystalline domains is a promising design principle for mass transport in semicrystalline polymer materials without compromising their mechanical stability.
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Affiliation(s)
- Trevor D Roberts
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Rongfeng Yuan
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Limin Xiang
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Milan Delor
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Ravi Pokhrel
- DuPont Electronics and Imaging, Marlborough, Massachusetts 01752, United States
| | - Ke Yang
- DuPont Electronics and Imaging, Marlborough, Massachusetts 01752, United States
| | - Emad Aqad
- DuPont Electronics and Imaging, Marlborough, Massachusetts 01752, United States
| | - Tomas Marangoni
- DuPont Electronics and Imaging, Marlborough, Massachusetts 01752, United States
| | - Peter Trefonas
- DuPont Electronics and Imaging, Marlborough, Massachusetts 01752, United States
| | - Ke Xu
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
- STROBE, National Science Foundation Science and Technology Center, University of California Berkeley, Berkeley, California 94720, United States
| | - Naomi S Ginsberg
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
- STROBE, National Science Foundation Science and Technology Center, University of California Berkeley, Berkeley, California 94720, United States
- Department of Physics, University of California Berkeley, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli Energy NanoSciences Institute at Berkeley, Berkeley, California 94720, United States
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19
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Kumar P, Theeyancheri L, Chaki S, Chakrabarti R. Transport of probe particles in a polymer network: effects of probe size, network rigidity and probe-polymer interaction. SOFT MATTER 2019; 15:8992-9002. [PMID: 31681926 DOI: 10.1039/c9sm01822k] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fundamental understanding of the effect of microscopic parameters on the dynamics of probe particles in different complex environments has wide implications. Examples include diffusion of proteins in biological hydrogels, porous media, polymer matrix, etc. Here, we use extensive molecular dynamics simulations to investigate the dynamics of the probe particle in a polymer network on a diamond lattice, which provides substantial crowding to mimic the cellular environment. Our simulations show that the dynamics of the probe increasingly becomes restricted, non-Gaussian and subdiffusive on increasing the network rigidity, binding affinity and probe size. In addition, the velocity autocorrelation functions show negative dips owing to the viscoelasticity and caging due to the surrounding network. These observations go with the general experimental findings. Importantly, for a probe particle of size comparable to the mesh size, unrestricted motion engulfing large length scales has been observed. This happens with a more flexible polymer network, which is easily pushed by the bigger probe. On increasing the rigidity of the network, the bigger probe can not efficiently push the network and as a result the long tail disappears. Our study gives a general qualitative picture of the transport of probes in a gel-like medium, as encountered in different contexts.
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Affiliation(s)
- Praveen Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| | - Ligesh Theeyancheri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| | - Subhasish Chaki
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| | - Rajarshi Chakrabarti
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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20
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Garay RO, Del Rosso PG, Romagnoli MJ, Almassio MF, Schvval AB. Photoactive thin films of terphenylene-based amorphous polymers. Synthesis, electrooptical properties, and role of photoquenching and inner filter effects in the chemosensing of nitroaromatics. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.112016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Jung J, Kwon T, Oh Y, Lee YR, Sung BJ. Spatial Dependence of Non-Gaussian Diffusion of Nanoparticles in Free-Standing Thin Polymer Films. J Phys Chem B 2019; 123:9250-9259. [PMID: 31589036 DOI: 10.1021/acs.jpcb.9b07236] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The addition of nanoparticles (NPs) to a free-standing polymer film affects the properties of the film such as viscosity and glass transition temperature. Recent experiments, for example, showed that the glass transition temperature of thin polymer films was dependent on how NPs were distributed within the polymer films. However, the spatial arrangement of NPs in free-standing polymer films and its effect on the diffusion of NPs and polymers remain elusive at a molecular level. In this study, we employ generic coarse-grained models for polymers and NPs and perform extensive molecular dynamics simulations to investigate the diffusion of polymers and NPs in free-standing thin polymer films. We find that small NPs are likely to stay at the interfacial region of the polymer film, while large NPs tend to stay at the center of the film. On the other hand, as the interaction between a NP and a monomer becomes more attractive, the NP is more likely to be placed at the film center. The diffusion of monomers slows down slightly as more NPs are added to the film. Interestingly, the NP diffusion is dependent strongly on the spatial arrangement of the NPs: NPs at the interfacial region diffuse faster and undergo more non-Gaussian diffusion than NPs at the film center, which implies that the interfacial region would be more mobile and dynamically heterogeneous than the film center. We also find that the mechanism for non-Gaussian diffusion of NPs at the film center differs from that at the interfacial region and that the NP diffusion would reflect the local viscosity of the polymer films.
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Affiliation(s)
- Jinkwan Jung
- Department of Chemistry , Sogang University , Seoul 04107 , Republic of Korea
| | - Taejin Kwon
- Department of Chemistry , Sogang University , Seoul 04107 , Republic of Korea
| | - Younghoon Oh
- Department of Chemistry , Sogang University , Seoul 04107 , Republic of Korea
| | - Young-Ro Lee
- Department of Chemistry , Sogang University , Seoul 04107 , Republic of Korea
| | - Bong June Sung
- Department of Chemistry , Sogang University , Seoul 04107 , Republic of Korea
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22
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Choi J, Lee S, Choe J, Chung Y, Lee YE, Kim J, Kim M, Paeng K. How Tethered Probes Report the Dynamics of a Polymer near the Glass Transition. ACS Macro Lett 2019; 8:1181-1186. [PMID: 35619450 DOI: 10.1021/acsmacrolett.9b00423] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
How tethered probes report dynamics of host polymers near the glass transition was investigated by changing the length of the flexible linkers and the number of tethering points via imaging rotational fluorescence correlation microscopy and compared with free probes of different sizes. The results show that tethering did not alter the temperature-dependence of polymer dynamics and the shape of the correlation decay reported by the probe; however, the rotation slowed down up to ≈1 decade when both ends of the probe were restricted with short alkyl chain linkers. Upon comparison with the bigger free probe, the mechanism of the slowdown was attributed to the restricted motion upon tethering for tethered probes compared to averaging over different regions of the dynamic heterogeneity for the bigger probe. If the size of the probe was comparable to that of the dynamic heterogeneity of the system, tethered probes accurately report dynamics relevant to glass transition, regardless of tethering conditions.
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Affiliation(s)
- Jiwon Choi
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Soohyun Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jongwon Choe
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Yura Chung
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yae Eun Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jisu Kim
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Myungwoong Kim
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Keewook Paeng
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
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23
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Manz AS, Aly M, Kaufman LJ. Correlating fragility and heterogeneous dynamics in polystyrene through single molecule studies. J Chem Phys 2019; 151:084501. [PMID: 31470706 DOI: 10.1063/1.5114905] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Many macroscopic properties of polymers depend on their molecular weight, with one notable example being glass transition temperature: polymers with higher molecular weights typically have higher glass transition temperatures than their lower molecular weight polymeric and oligomeric counterparts. Polymeric systems close to their glass transition temperatures also exhibit interesting properties, showing both high (and molecular weight dependent) fragility and strong evidence of dynamic heterogeneity. While studies have detailed the correlations between molecular weight and fragility, studies clearly detailing correlations between molecular weight and degree of heterogeneous dynamics are lacking. In this study, we use single molecule rotational measurements to investigate the impact of molecular weight on polystyrene's degree of heterogeneity near its glass transition temperature. To this end, two types of fluorescent probes are embedded in films composed of polystyrene ranging from 0.6 to 1364.0 kg mol-1. We find correlation between polystyrene molecular weight, fragility, and degree of dynamic heterogeneity as reported by single molecule stretching exponents but do not find clear correlation between these quantities and time scales associated with dynamic exchange.
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Affiliation(s)
- Alyssa S Manz
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Mariam Aly
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Laura J Kaufman
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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24
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Coceancigh H, Higgins DA, Ito T. Optical Microscopic Techniques for Synthetic Polymer Characterization. Anal Chem 2018; 91:405-424. [PMID: 30350610 DOI: 10.1021/acs.analchem.8b04694] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Herman Coceancigh
- Department of Chemistry , Kansas State University , 213 CBC Building , Manhattan , Kansas 66506-0401 , United States
| | - Daniel A Higgins
- Department of Chemistry , Kansas State University , 213 CBC Building , Manhattan , Kansas 66506-0401 , United States
| | - Takashi Ito
- Department of Chemistry , Kansas State University , 213 CBC Building , Manhattan , Kansas 66506-0401 , United States
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25
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Manz AS, Paeng K, Kaufman LJ. Single molecule studies reveal temperature independence of lifetime of dynamic heterogeneity in polystyrene. J Chem Phys 2018; 148:204508. [PMID: 29865823 DOI: 10.1063/1.5031131] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Polymeric systems close to their glass transition temperature are known to exhibit heterogeneous dynamics that evolve both over time and space, comparable to the dynamics of small molecule glass formers. It remains unclear how temperature influences the degree of heterogeneous dynamics in such systems. In the following report, a fluorescent perylene dicarboximide probe molecule that reflects the full breadth of heterogeneity of the host was used to examine the temperature dependence of the dynamic heterogeneity lifetime in polystyrene at several temperatures ranging from the glass transition to 10 K above this temperature via single molecule microscopy. Contrary to prior reports, no apparent temperature dependence of time scales associated with dynamic heterogeneity was detected; indeed, the probe molecules report characteristic dynamic heterogeneity lifetimes 100-300 times the average alpha-relaxation time (τα) of the polystyrene host at all temperatures studied.
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Affiliation(s)
- Alyssa S Manz
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Keewook Paeng
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Laura J Kaufman
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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26
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Piatkowski L, Schanbacher C, Wackenhut F, Jamrozik A, Meixner AJ, Waluk J. Nature of Large Temporal Fluctuations of Hydrogen Transfer Rates in Single Molecules. J Phys Chem Lett 2018; 9:1211-1215. [PMID: 29470087 DOI: 10.1021/acs.jpclett.8b00299] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Double hydrogen transfer was monitored in single molecules of parent porphycene and its tetra- t-butyl derivative using confocal fluorescence microscopy. The molecules have been embedded in a polymer matrix. Under such conditions, a significant fraction of the population reveals a huge decrease of the tautomerization rate with respect to the value obtained from ensemble studies in solution. This effect is explained by a model that assumes that the rate is determined by the reorganization coordinate that involves slow relaxation of the polymer matrix. The model provides indirect evidence for the dominant role of tunneling. It is proposed that tautomerization in single molecules of the porphycene family can be used to probe polymer relaxation dynamics on the time scale ranging from picoseconds to minutes.
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Affiliation(s)
- Lukasz Piatkowski
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland
| | - Christina Schanbacher
- Institute of Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 18 , D-72076 Tübingen , Germany
| | - Frank Wackenhut
- Institute of Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 18 , D-72076 Tübingen , Germany
| | - Agnieszka Jamrozik
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 18 , D-72076 Tübingen , Germany
| | - Jacek Waluk
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland
- Faculty of Mathematics and Science , Cardinal Stefan Wyszyński University , Dewajtis 5 , 01-815 Warsaw , Poland
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27
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Nevskyi O, Sysoiev D, Dreier J, Stein SC, Oppermann A, Lemken F, Janke T, Enderlein J, Testa I, Huhn T, Wöll D. Fluorescent Diarylethene Photoswitches-A Universal Tool for Super-Resolution Microscopy in Nanostructured Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:1703333. [PMID: 29325203 DOI: 10.1002/smll.201703333] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/03/2017] [Indexed: 06/07/2023]
Abstract
Super-resolution fluorescence microscopy allows for unprecedented in situ visualization of biological structures, but its application to materials science has so far been comparatively limited. One of the main reasons is the lack of powerful dyes that allow for labeling and photoswitching in materials science systems. In this study it is shown that appropriate substitution of diarylethenes bearing a fluorescent closed and dark open form paves the way for imaging nanostructured materials with three of the most popular super-resolution fluorescence microscopy methods that are based on different concepts to achieve imaging beyond the diffraction limit of light. The key to obtain optimal resolution lies in a proper control over the photochemistry of the photoswitches and its adaption to the system to be imaged. It is hoped that the present work will provide researchers with a guide to choose the best photoswitch derivative for super-resolution microscopy in materials science, just like the correct choice of a Swiss Army Knife's tool is essential to fulfill a given task.
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Affiliation(s)
- Oleksii Nevskyi
- Institute for Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Dmytro Sysoiev
- Department of Chemistry, University of Konstanz, Universitätsstr. 10, 78464, Konstanz, Germany
| | - Jes Dreier
- Science for Life Laboratory, KTH Royal Institute of Technology, Tomtebodavägen 23A, 17121, Solna, Sweden
| | - Simon Christoph Stein
- III. Institute of Physics - Biophysics, Georg-August University, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Alex Oppermann
- Institute for Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Florian Lemken
- Institute for Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Tobias Janke
- Institute for Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Jörg Enderlein
- III. Institute of Physics - Biophysics, Georg-August University, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Ilaria Testa
- Science for Life Laboratory, KTH Royal Institute of Technology, Tomtebodavägen 23A, 17121, Solna, Sweden
| | - Thomas Huhn
- Department of Chemistry, University of Konstanz, Universitätsstr. 10, 78464, Konstanz, Germany
| | - Dominik Wöll
- Institute for Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
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28
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Baier M, Wöll D, Mecking S. Diffusion of Molecular and Macromolecular Polyolefin Probes in Cylindrical Block Copolymer Structures As Observed by High Temperature Single Molecule Fluorescence Microscopy. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Moritz Baier
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - Dominik Wöll
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - Stefan Mecking
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
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29
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Kim V, Piatkowski L, Pszona M, Jäger R, Ostapko J, Sepioł J, Meixner AJ, Waluk J. Unusual effects in single molecule tautomerization: hemiporphycene. Phys Chem Chem Phys 2018; 20:26591-26596. [DOI: 10.1039/c8cp05836a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Temporal evolution of the fluorescence spectra of individual hemiporphycene molecules reveals unusual double hydrogen transfer reaction dynamics.
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Affiliation(s)
- Victoriya Kim
- Institute of Physical and Theoretical Chemistry and LISA+
- University of Tübingen
- D-72076 Tübingen
- Germany
| | | | - Maria Pszona
- Institute of Physical Chemistry
- Polish Academy of Sciences
- Poland
| | - Regina Jäger
- Institute of Physical and Theoretical Chemistry and LISA+
- University of Tübingen
- D-72076 Tübingen
- Germany
| | - Jakub Ostapko
- Institute of Physical Chemistry
- Polish Academy of Sciences
- Poland
| | - Jerzy Sepioł
- Institute of Physical Chemistry
- Polish Academy of Sciences
- Poland
| | - Alfred J. Meixner
- Institute of Physical and Theoretical Chemistry and LISA+
- University of Tübingen
- D-72076 Tübingen
- Germany
| | - Jacek Waluk
- Institute of Physical Chemistry
- Polish Academy of Sciences
- Poland
- Faculty of Mathematics and Science
- Cardinal Stefan Wyszyński University
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30
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Burroughs MJ, Christie D, Gray LAG, Chowdhury M, Priestley RD. 21st Century Advances in Fluorescence Techniques to Characterize Glass‐Forming Polymers at the Nanoscale. MACROMOL CHEM PHYS 2017. [DOI: 10.1002/macp.201700368] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Mary J. Burroughs
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Dane Christie
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Laura A. G. Gray
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Mithun Chowdhury
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Rodney D. Priestley
- Department of Chemical and Biological Engineering Princeton Institute for the Science and Technology of Materials Princeton University Princeton NJ 08544 USA
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31
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Qiu Z, Chu EKK, Jiang M, Gui C, Xie N, Qin W, Alam P, Kwok RTK, Lam JWY, Tang BZ. A Simple and Sensitive Method for an Important Physical Parameter: Reliable Measurement of Glass Transition Temperature by AIEgens. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01070] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Zijie Qiu
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Eric K. K. Chu
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Meijuan Jiang
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Chen Gui
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Ni Xie
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Wei Qin
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Parvej Alam
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Ryan T. K. Kwok
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Jacky W. Y. Lam
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Ben Zhong Tang
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
- Guangdong
Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
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32
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Xu J, Zhang Y, Zhou H, Hong Y, Zuo B, Wang X, Zhang L. Probing the Utmost Distance of Polymer Dynamics Suppression by a Substrate by Investigating the Diffusion of Fluorinated Tracer-Labeled Polymer Chains. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01158] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Jianquan Xu
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Yizhi Zhang
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Hao Zhou
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Yongming Hong
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Biao Zuo
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Xinping Wang
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Li Zhang
- Department of Chemistry,
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
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33
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Napolitano S, Glynos E, Tito NB. Glass transition of polymers in bulk, confined geometries, and near interfaces. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:036602. [PMID: 28134134 DOI: 10.1088/1361-6633/aa5284] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
When cooled or pressurized, polymer melts exhibit a tremendous reduction in molecular mobility. If the process is performed at a constant rate, the structural relaxation time of the liquid eventually exceeds the time allowed for equilibration. This brings the system out of equilibrium, and the liquid is operationally defined as a glass-a solid lacking long-range order. Despite almost 100 years of research on the (liquid/)glass transition, it is not yet clear which molecular mechanisms are responsible for the unique slow-down in molecular dynamics. In this review, we first introduce the reader to experimental methodologies, theories, and simulations of glassy polymer dynamics and vitrification. We then analyse the impact of connectivity, structure, and chain environment on molecular motion at the length scale of a few monomers, as well as how macromolecular architecture affects the glass transition of non-linear polymers. We then discuss a revised picture of nanoconfinement, going beyond a simple picture based on interfacial interactions and surface/volume ratio. Analysis of a large body of experimental evidence, results from molecular simulations, and predictions from theory supports, instead, a more complex framework where other parameters are relevant. We focus discussion specifically on local order, free volume, irreversible chain adsorption, the Debye-Waller factor of confined and confining media, chain rigidity, and the absolute value of the vitrification temperature. We end by highlighting the molecular origin of distributions in relaxation times and glass transition temperatures which exceed, by far, the size of a chain. Fast relaxation modes, almost universally present at the free surface between polymer and air, are also remarked upon. These modes relax at rates far larger than those characteristic of glassy dynamics in bulk. We speculate on how these may be a signature of unique relaxation processes occurring in confined or heterogeneous polymeric systems.
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Affiliation(s)
- Simone Napolitano
- Laboratory of Polymer and Soft Matter Dynamics, Faculté des Sciences, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, 1050 Brussels, Belgium
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34
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Spiess HW. 50th Anniversary Perspective: The Importance of NMR Spectroscopy to Macromolecular Science. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02736] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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35
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Bhattacharya S, Sharma DK, De S, Mahato J, Chowdhury A. Heterogeneity during Plasticization of Poly(vinylpyrrolidone): Insights from Reorientational Mobility of Single Fluorescent Probes. J Phys Chem B 2016; 120:12404-12415. [DOI: 10.1021/acs.jpcb.6b08584] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sukanya Bhattacharya
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | - Suman De
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Jaladhar Mahato
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Arindam Chowdhury
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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36
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Habuchi S, Yamamoto T, Tezuka Y. Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level. J Vis Exp 2016. [PMID: 27768083 DOI: 10.3791/54503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.
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Affiliation(s)
- Satoshi Habuchi
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST);
| | - Takuya Yamamoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University; Department of Organic and Polymeric Materials, Tokyo Institute of Technology
| | - Yasuyuki Tezuka
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology;
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37
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Abstract
Biosensors for highly sensitive, selective, and rapid quantification of specific biomolecules make great contributions to biomedical research, especially molecular diagnostics. However, conventional methods for biomolecular assays often suffer from insufficient sensitivity and poor specificity. In some case (e.g., early disease diagnostics), the concentration of target biomolecules is too low to be detected by these routine approaches, and cumbersome procedures are needed to improve the detection sensitivity. Therefore, there is an urgent need for rapid and ultrasensitive analytical tools. In this respect, single-molecule fluorescence approaches may well satisfy the requirement and hold promising potential for the development of ultrasensitive biosensors. Encouragingly, owing to the advances in single-molecule microscopy and spectroscopy over past decades, the detection of single fluorescent molecule comes true, greatly boosting the development of highly sensitive biosensors. By in vitro/in vivo labeling of target biomolecules with proper fluorescent tags, the quantification of certain biomolecule at the single-molecule level is achieved. In comparison with conventional ensemble measurements, single-molecule detection-based analytical methods possess the advantages of ultrahigh sensitivity, good selectivity, rapid analysis time, and low sample consumption. Consequently, single-molecule detection may be potentially employed as an ideal analytical approach to quantify low-abundant biomolecules with rapidity and simplicity. In this Account, we will summarize our efforts for developing a series of ultrasensitive biosensors based on single-molecule counting. Single-molecule counting is a member of single-molecule detection technologies and may be used as a very simple and ultrasensitive method to quantify target molecules by simply counting the individual fluorescent bursts. In the fluorescent sensors, the signals of target biomolecules may be translated to the fluorescence signals by specific in vitro/in vivo fluorescent labeling, and consequently, the fluorescent molecules indicate the presence of target molecules. The resultant fluorescence signals may be simply counted by either microfluidic device-integrated confocal microscopy or total internal reflection fluorescence-based single-molecule imaging. We have developed a series of single-molecule counting-based biosensors which can be classified as separation-free and separation-assisted assays. As a proof-of-concept, we demonstrate the applications of single-molecule counting-based biosensors for sensitive detection of various target biomolecules such as DNAs, miRNAs, proteins, enzymes, and intact cells, which may function as the disease-related biomarkers. Moreover, we give a summary of future directions to expand the usability of single-molecule counting-based biosensors including (1) the development of more user-friendly and automated instruments, (2) the discovery of new fluorescent labels and labeling strategies, and (3) the introduction of new concepts for the design of novel biosensors. Due to their high sensitivity, good selectivity, rapidity, and simplicity, we believe that the single-molecule counting-based fluorescent biosensors will indubitably find wide applications in biological research, clinical diagnostics, and drug discovery.
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Affiliation(s)
- Fei Ma
- College
of Chemistry, Chemical Engineering and Materials Science, Collaborative
Innovation Center of Functionalized Probes for Chemical Imaging in
Universities of Shandong, Key Laboratory of Molecular and Nano Probes,
Ministry of Education, Shandong Provincial Key Laboratory of Clean
Production of Fine Chemicals, Shandong Normal University, Jinan 250014, China
| | - Ying Li
- Medical
School, Shenzhen University, Shenzhen 518060, China
| | - Bo Tang
- College
of Chemistry, Chemical Engineering and Materials Science, Collaborative
Innovation Center of Functionalized Probes for Chemical Imaging in
Universities of Shandong, Key Laboratory of Molecular and Nano Probes,
Ministry of Education, Shandong Provincial Key Laboratory of Clean
Production of Fine Chemicals, Shandong Normal University, Jinan 250014, China
| | - Chun-yang Zhang
- College
of Chemistry, Chemical Engineering and Materials Science, Collaborative
Innovation Center of Functionalized Probes for Chemical Imaging in
Universities of Shandong, Key Laboratory of Molecular and Nano Probes,
Ministry of Education, Shandong Provincial Key Laboratory of Clean
Production of Fine Chemicals, Shandong Normal University, Jinan 250014, China
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Paeng K, Kaufman LJ. Single Molecule Experiments Reveal the Dynamic Heterogeneity and Exchange Time Scales of Polystyrene near the Glass Transition. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00097] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Keewook Paeng
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
- Department
of Chemistry, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Laura J. Kaufman
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
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Krause S, Neumann M, Fröbe M, Magerle R, von Borczyskowski C. Monitoring Nanoscale Deformations in a Drawn Polymer Melt with Single-Molecule Fluorescence Polarization Microscopy. ACS NANO 2016; 10:1908-1917. [PMID: 26831762 DOI: 10.1021/acsnano.5b05729] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Elongating a polymer melt causes polymer segments to align and polymer coils to deform along the drawing direction. Despite the importance of this molecular response for understanding the viscoelastic properties and relaxation behavior of polymeric materials, studies on the single-molecule level are rare and were not performed in real time. Here we use single-molecule fluorescence polarization microscopy for monitoring the position and orientation of single fluorescent perylene diimide molecules embedded in a free-standing thin film of a polymethyl acrylate (PMA) melt with a time resolution of 500 ms during the film drawing and the subsequent stress relaxation period. The orientation distribution of the perylene diimide molecules is quantitatively described with a model of rod-like objects embedded in a uniaxially elongated matrix. The orientation of the fluorescent probe molecules is directly coupled to the local deformation of the PMA melt, which we derive from the distances between individual dye molecules. In turn, the fluorescence polarization monitors the shape deformation of the polymer coils on a length scale of 5 nm. During stress relaxation, the coil shape relaxes four times more slowly than the mechanical stress. This shows that stress relaxation involves processes on length scales smaller than a polymer coil. Our work demonstrates how optical spectroscopy and microscopy can be used to study the coupling of individual fluorescent probe molecules to their embedding polymeric matrix and to an external mechanical stimulus on the single-molecule level.
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Affiliation(s)
- Stefan Krause
- Fakultät für Naturwissenschaften, Technische Universität Chemnitz , 09107 Chemnitz, Germany
| | - Martin Neumann
- Fakultät für Naturwissenschaften, Technische Universität Chemnitz , 09107 Chemnitz, Germany
| | - Melanie Fröbe
- Fakultät für Naturwissenschaften, Technische Universität Chemnitz , 09107 Chemnitz, Germany
| | - Robert Magerle
- Fakultät für Naturwissenschaften, Technische Universität Chemnitz , 09107 Chemnitz, Germany
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40
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Nie Y, Zhou Z, Hao T, Ye X, Yang W. The Distribution of Glass Transition Temperatures in Ultrathin Polymer Films Controlled by Segment Density or Interfacial Interaction. MACROMOL THEOR SIMUL 2016. [DOI: 10.1002/mats.201500062] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yijing Nie
- Institute of Polymer Materials; School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Zhiping Zhou
- Institute of Polymer Materials; School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Tongfan Hao
- Institute of Polymer Materials; School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Xubo Ye
- Institute of Polymer Materials; School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Wenming Yang
- Institute of Polymer Materials; School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
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41
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Dong W, Pina J, Pan Y, Preis E, Seixas de Melo JS, Scherf U. Polycarbazoles and polytriphenylamines showing aggregation-induced emission (AIE) and intramolecular charge transfer (ICT) behavior for the optical detection of nitroaromatic compounds. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.08.064] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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42
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Abadi M, Serag MF, Habuchi S. Single-Molecule Imaging Reveals Topology Dependent Mutual Relaxation of Polymer Chains. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01388] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Maram Abadi
- Biological and Environmental
Sciences and Engineering Division, King Abdullah University of Science and Technology, P.O. Box 4700, KAUST, Bldg 2 Room 4277, Thuwal 23955-6900, Saudi Arabia
| | - Maged F. Serag
- Biological and Environmental
Sciences and Engineering Division, King Abdullah University of Science and Technology, P.O. Box 4700, KAUST, Bldg 2 Room 4277, Thuwal 23955-6900, Saudi Arabia
| | - Satoshi Habuchi
- Biological and Environmental
Sciences and Engineering Division, King Abdullah University of Science and Technology, P.O. Box 4700, KAUST, Bldg 2 Room 4277, Thuwal 23955-6900, Saudi Arabia
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43
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Ye X, Zhou Z, Nie Y, Ma P, Hao T, Yang W, Lu H. Comparative Study on Dynamical Heterogeneity of Ring and Linear Polymers. MACROMOL THEOR SIMUL 2015. [DOI: 10.1002/mats.201500042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xubo Ye
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Zhiping Zhou
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Yijing Nie
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Ping Ma
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Tongfan Hao
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Wenming Yang
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
| | - Haifeng Lu
- School of Materials Science and Engineering; Jiangsu University; 301 Xuefu Road Zhenjiang 212013 China
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44
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Habuchi S, Fujiwara S, Yamamoto T, Tezuka Y. Single-molecule imaging reveals topological isomer-dependent diffusion by 4-armed star and dicyclic 8-shaped polymers. Polym Chem 2015. [DOI: 10.1039/c5py00534e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The diffusion modes of the fluorophore incorporated 4-armed star and dicyclic 8-shaped polymers were investigated at the molecular level by means of single-molecule fluorescence imaging.
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Affiliation(s)
- Satoshi Habuchi
- Biological and Environmental Sciences and Engineering
- King Abdullah University of Science and Technology
- Thuwal 23955-6900
- Kingdom of Saudi Arabia
| | - Susumu Fujiwara
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo 152-8552
- Japan
| | - Takuya Yamamoto
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo 152-8552
- Japan
| | - Yasuyuki Tezuka
- Department of Organic and Polymeric Materials
- Tokyo Institute of Technology
- Tokyo 152-8552
- Japan
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45
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Bao S, Wu Q, Qin W, Yu Q, Wang J, Liang G, Tang BZ. Sensitive and reliable detection of glass transition of polymers by fluorescent probes based on AIE luminogens. Polym Chem 2015. [DOI: 10.1039/c5py00308c] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A sensitive and reliable approach for the detection of the glass transition of polymers using AIE luminogens as fluorescent probes was reported.
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Affiliation(s)
- Suping Bao
- DSAP lab
- PCFM lab
- GDHPPC lab
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
| | - Qihua Wu
- DSAP lab
- PCFM lab
- GDHPPC lab
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
| | - Wei Qin
- HKUST-Shenzhen Research Institute
- Nanshan, Shenzhen
- China 518057
- Department of Chemistry
- Institute for Advanced Study
| | - Qiuling Yu
- DSAP lab
- PCFM lab
- GDHPPC lab
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
| | - Jing Wang
- DSAP lab
- PCFM lab
- GDHPPC lab
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
| | - Guodong Liang
- DSAP lab
- PCFM lab
- GDHPPC lab
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
| | - Ben Zhong Tang
- HKUST-Shenzhen Research Institute
- Nanshan, Shenzhen
- China 518057
- Department of Chemistry
- Institute for Advanced Study
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46
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Nie Y, Ye X, Zhou Z, Hao T, Yang W, Lu H. Structural characteristics of a cooperatively rearranging region during the glass transition of a polymer system. RSC Adv 2015. [DOI: 10.1039/c4ra16849f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Local ordered structures are formed during glass transition. These local orders preferred to move cooperatively during relaxation. In other words, the cooperatively rearranging regions contained some local order.
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Affiliation(s)
- Yijing Nie
- School of Materials Science and Engineering
- Jiangsu University
- Zhenjiang 212013
- China
| | - Xubo Ye
- School of Materials Science and Engineering
- Jiangsu University
- Zhenjiang 212013
- China
| | - Zhiping Zhou
- School of Materials Science and Engineering
- Jiangsu University
- Zhenjiang 212013
- China
| | - Tongfan Hao
- School of Materials Science and Engineering
- Jiangsu University
- Zhenjiang 212013
- China
| | - Wenming Yang
- School of Materials Science and Engineering
- Jiangsu University
- Zhenjiang 212013
- China
| | - Haifeng Lu
- School of Materials Science and Engineering
- Jiangsu University
- Zhenjiang 212013
- China
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47
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Ito S, Taga Y, Hiratsuka K, Takei S, Kitagawa D, Kobatake S, Miyasaka H. Restricted diffusion of guest molecules in polymer thin films on solid substrates as revealed by three-dimensional single-molecule tracking. Chem Commun (Camb) 2015. [DOI: 10.1039/c5cc03663a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
3D single-molecule tracking revealed that the translational diffusion of guest dyes in poly(2-hydroxyethyl acrylate) thin films on glass substrates was confined in a horizontal layer at a distance longer than 300–700 nm from the surface of the substrate.
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Affiliation(s)
- Syoji Ito
- Division of Frontier Materials Science and Center for Promotion of Advanced Interdisciplinary Research
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
| | - Yuhei Taga
- Division of Frontier Materials Science and Center for Promotion of Advanced Interdisciplinary Research
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
| | - Kengo Hiratsuka
- Division of Frontier Materials Science and Center for Promotion of Advanced Interdisciplinary Research
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
| | - Satoshi Takei
- Eco-material Engineering
- Toyama Prefectural University
- Imizu
- Japan
| | - Daichi Kitagawa
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka City University
- Japan
| | - Seiya Kobatake
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka City University
- Japan
| | - Hiroshi Miyasaka
- Division of Frontier Materials Science and Center for Promotion of Advanced Interdisciplinary Research
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
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48
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Stempfle B, Große A, Ferse B, Arndt KF, Wöll D. Anomalous diffusion in thermoresponsive polymer-clay composite hydrogels probed by wide-field fluorescence microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:14056-61. [PMID: 25358126 DOI: 10.1021/la503571j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Thermoresponsive materials exhibit an enormous potential for tissue engineering, separation systems, and drug delivery. We investigated the diffusion of laponite clay nanoparticles, which serve as physical cross-linkers to achieve improved material properties in poly(N-isopropylacrylamide) (PNIPAM)-clay composite hydrogels close to the gel point. The networks are formed through physical interactions between PNIPAM chains and clay nanoparticles after these two components are mixed. In contrast to previous studies, a covalent labeling strategy was chosen to minimize the amount of free dyes in solution. Single-particle tracking of the labeled clay nanoparticles showed that their diffusion is anomalous at all temperatures used in this study, reflecting the viscoelastic behavior as a cross-linker. Stepwise heating from 24 to 38 °C resulted in a slight increase of the diffusion coefficient and the anomality parameter α up to the volume phase transition temperature of ca. 31 °C, which was followed by a significant drop of both parameters, reflecting strongly hindered motion of the collapsed nanoparticle aggregates.
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Affiliation(s)
- Beate Stempfle
- Faculty of Chemistry, University of Konstanz , Universitätsstr.10, 78464 Konstanz, Germany
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49
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Forrey C, Saylor DM, Silverstein JS, Douglas JF, Davis EM, Elabd YA. Prediction and validation of diffusion coefficients in a model drug delivery system using microsecond atomistic molecular dynamics simulation and vapour sorption analysis. SOFT MATTER 2014; 10:7480-7494. [PMID: 25115846 DOI: 10.1039/c4sm01297f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Diffusion of small to medium sized molecules in polymeric medical device materials underlies a broad range of public health concerns related to unintended leaching from or uptake into implantable medical devices. However, obtaining accurate diffusion coefficients for such systems at physiological temperature represents a formidable challenge, both experimentally and computationally. While molecular dynamics simulation has been used to accurately predict the diffusion coefficients, D, of a handful of gases in various polymers, this success has not been extended to molecules larger than gases, e.g., condensable vapours, liquids, and drugs. We present atomistic molecular dynamics simulation predictions of diffusion in a model drug eluting system that represent a dramatic improvement in accuracy compared to previous simulation predictions for comparable systems. We find that, for simulations of insufficient duration, sub-diffusive dynamics can lead to dramatic over-prediction of D. We present useful metrics for monitoring the extent of sub-diffusive dynamics and explore how these metrics correlate to error in D. We also identify a relationship between diffusion and fast dynamics in our system, which may serve as a means to more rapidly predict diffusion in slowly diffusing systems. Our work provides important precedent and essential insights for utilizing atomistic molecular dynamics simulations to predict diffusion coefficients of small to medium sized molecules in condensed soft matter systems.
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Affiliation(s)
- Christopher Forrey
- Division of Chemistry and Materials Science, Center for Devices and Radiological Health, US Food and Drug Administration, USA.
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50
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Abstract
Much of the interesting behavior that has been observed in supercooled liquids appears to be related to dynamic heterogeneity, the presence of distinct dynamic environments - with no apparent underlying structural basis - in these systems. To most directly interrogate these environments, proposed to span regions just a few nanometers across, molecular length scale probes are required. Single molecule fluorescent microscopy was introduced to the field a decade ago and has provided strong evidence of dynamic heterogeneity in supercooled systems. However, only more recently has the full set of challenges associated with interpreting results of these experiments been described. With a fuller understanding of these challenges in hand, single molecule measurements can be employed to provide a more precise picture of dynamic heterogeneity in supercooled liquids and other complex systems. In this tutorial review, experimental and data analysis details are presented for the most commonly employed single molecule approach to studying supercooled liquids, the measurement of rotational dynamics of single molecule probes. Guidance is provided in experimental set-up and probe selection, with a focus on choices that affect data interpretation and probe sensitivity to dynamic heterogeneity.
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Affiliation(s)
- Keewook Paeng
- Department of Chemistry, Columbia University, New York, NY 10027, USA.
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