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Wang Z, Wang ZG, Shi AC, Lu Y, An L. Behaviors of a Polymer Chain in Channels: From Zimm to Rouse Dynamics. Macromolecules 2023. [DOI: 10.1021/acs.macromol.3c00013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Affiliation(s)
- Zhenhua Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
| | - Zhen-Gang Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - An-Chang Shi
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Yuyuan Lu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
| | - Lijia An
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
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2
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Ghosal A, Cherayil BJ. The effects of slit-like confinement on flow-induced polymer deformation. J Chem Phys 2017; 147:064905. [PMID: 28810795 DOI: 10.1063/1.4997639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
This paper is broadly concerned with the dynamics of a polymer confined to a rectangular slit of width D and deformed by a planar elongational flow of strength γ̇. It is interested, more specifically, in the nature of the coil-stretch transition that such polymers undergo when the flow strength γ̇ is varied, and in the degree to which this transition is affected by the presence of restrictive boundaries. These issues are explored within the framework of a finitely extensible Rouse model that includes pre-averaged surface-mediated hydrodynamic interactions. Calculations of the chain's steady-state fractional extension x using this model suggest that different modes of relaxation (which are characterized by an integer p) exert different levels of control on the coil-stretch transition. In particular, the location of the transition (as identified from the graph of x versus the Weissenberg number Wi, a dimensionless parameter defined by the product of γ̇ and the time constant τp of a relaxation mode p) is found to vary with the choice of τp. In particular, when τ1 is used in the definition of Wi, the x vs. Wi data for different D lie on a single curve, but when τ3 is used instead (with τ3 > τ1) the corresponding data lie on distinct curves. These findings are in close qualitative agreement with a number of experimental results on confinement effects on DNA stretching in electric fields. Similar D-dependent trends are seen in our calculated force vs. Wi data, but force vs. x data are essentially D-independent and lie on a single curve.
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Affiliation(s)
- Aishani Ghosal
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Binny J Cherayil
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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Ye Y, Du Z, Tian M, Zhang L, Mi J. Diffusive dynamics of polymer chains in an array of nanoposts. Phys Chem Chem Phys 2017; 19:380-387. [DOI: 10.1039/c6cp07217h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The diffusion of the head, side, and middle segments in confined polymer chains displays different dynamics in different directions.
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Affiliation(s)
- Yi Ye
- State Key Laboratory of Organic-Inorganic Composites
- Beijing University of Chemical Technology
- Beijing 100029
- China
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials
| | - Zhongjie Du
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials
- Beijing University of Chemical Technology
- Beijing
- China
| | - Ming Tian
- State Key Laboratory of Organic-Inorganic Composites
- Beijing University of Chemical Technology
- Beijing 100029
- China
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials
| | - Liqun Zhang
- State Key Laboratory of Organic-Inorganic Composites
- Beijing University of Chemical Technology
- Beijing 100029
- China
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials
| | - Jianguo Mi
- State Key Laboratory of Organic-Inorganic Composites
- Beijing University of Chemical Technology
- Beijing 100029
- China
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Muralidhar A, Dorfman KD. Kirkwood diffusivity of long semiflexible chains in nanochannel confinement. Macromolecules 2015; 48:2829-2839. [PMID: 26166846 PMCID: PMC4494130 DOI: 10.1021/acs.macromol.5b00377] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We compute the axial diffusivity of asymptotically long semiflexible polymers confined in square channels. Our calculations employ the Kirkwood approximation of the mobility tensor by combining computational fluid dynamics (CFD) calculations of the hydrodynamic tensor in channel confinement with pruned-enriched Rosenbluth method (PERM) simulations of a discrete wormlike chain model. Three key results emerge from our study. First, for the classic de Gennes regime, we confirm that Brochard and de Gennes' blob theory correctly predicts the scaling of the axial diffusivity, contrary to the conclusions of previous analyses. Second, for the extended de Gennes regime, we show that a modified blob theory, which has been used to incorporate the effect of local stiffness on DNA diffusion in nanoslits, explains the deviation from the prediction of classic blob theory for diffusion in nanochannels. Third, we provide a calculation similar to the modified blob theory to explain the relative insensitivity of the diffusivity to channel size for channels between the extended de Gennes regime and the Odijk regime, which is the most relevant regime for experiments and technological applications of DNA confinement in nanochannels. Our results are not only relevant to the dynamics of confined semiflexible polymers such as DNA, but also reveal interesting analogies between confinement in channels and slits.
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Affiliation(s)
- Abhiram Muralidhar
- Department of Chemical Engineering and Materials Science, University of Minnesota –Twin Cities, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA
| | - Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota –Twin Cities, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA
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Dorfman KD, Gupta D, Jain A, Muralidhar A, Tree DR. Hydrodynamics of DNA confined in nanoslits and nanochannels. THE EUROPEAN PHYSICAL JOURNAL. SPECIAL TOPICS 2014; 223:3179-3200. [PMID: 25566349 PMCID: PMC4282777 DOI: 10.1140/epjst/e2014-02326-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Modeling the dynamics of a confined, semi exible polymer is a challenging problem, owing to the complicated interplay between the configurations of the chain, which are strongly affected by the length scale for the confinement relative to the persistence length of the chain, and the polymer-wall hydrodynamic interactions. At the same time, understanding these dynamics are crucial to the advancement of emerging genomic technologies that use confinement to stretch out DNA and "read" a genomic signature. In this mini-review, we begin by considering what is known experimentally and theoretically about the friction of a wormlike chain such as DNA confined in a slit or a channel. We then discuss how to estimate the friction coefficient of such a chain, either with dynamic simulations or via Monte Carlo sampling and the Kirk-wood pre-averaging approximation. We then review our recent work on computing the diffusivity of DNA in nanoslits and nanochannels, and conclude with some promising avenues for future work and caveats about our approach.
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Affiliation(s)
- Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455 USA
| | - Damini Gupta
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455 USA
| | - Aashish Jain
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455 USA
| | - Abhiram Muralidhar
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455 USA
| | - Douglas R. Tree
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455 USA
- Materials Research Laboratory, University of California – Santa Barbara, Santa Barbara, CA 93106 USA
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Bhattacharyya P, Cherayil BJ. The diffusion and relaxation of Gaussian chains in narrow rectangular slits. J Chem Phys 2013; 138:244904. [PMID: 23822271 DOI: 10.1063/1.4811332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The confinement of a polymer to volumes whose characteristic linear dimensions are comparable to or smaller than its bulk radius of gyration R(G,bulk) can produce significant changes in its static and dynamic properties, with important implications for the understanding of single-molecule processes in biology and chemistry. In this paper, we present calculations of the effects of a narrow rectangular slit of thickness d on the scaling behavior of the diffusivity D and relaxation time τr of a Gaussian chain of polymerization index N and persistence length l0. The calculations are based on the Rouse-Zimm model of chain dynamics, with the pre-averaged hydrodynamic interaction being obtained from the solutions to Stokes equations for an incompressible fluid in a parallel plate geometry in the limit of small d. They go beyond de Gennes' purely phenomenological analysis of the problem based on blobs, which has so far been the only analytical route to the determination of chain scaling behavior for this particular geometry. The present model predicts that D ∼ dN(-1)ln (N∕d(2)) and τr ∼ N(2)d(-1)[ln (N∕d(2))](-1) in the regime of moderate confinement, where l0 ≪ d < R(G,bulk). The corresponding results for the blob model have exactly the same power law behavior, but contain no logarithmic corrections; the difference suggests that segments within a blob may actually be partially draining and not non-draining as generally assumed.
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Affiliation(s)
- Pinaki Bhattacharyya
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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Dai L, Tree DR, van der Maarel JRC, Dorfman KD, Doyle PS. Revisiting blob theory for DNA diffusivity in slitlike confinement. PHYSICAL REVIEW LETTERS 2013; 110:168105. [PMID: 23679643 PMCID: PMC3670611 DOI: 10.1103/physrevlett.110.168105] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Indexed: 05/25/2023]
Abstract
Blob theory has been widely applied to describe polymer conformations and dynamics in nanoconfinement. In slit confinement, blob theory predicts a scaling exponent of 2/3 for polymer diffusivity as a function of slit height, yet a large body of experimental studies using DNA produce a scaling exponent significantly less than 2/3. In this work, we develop a theory that predicts that this discrepancy occurs because the segment correlation function for a semiflexible chain such as DNA does not follow the Flory exponent for length scales smaller than the persistence length. We show that these short length scale effects contribute significantly to the scaling for the DNA diffusivity, but do not appreciably affect the scalings for static properties. Our theory is fully supported by Monte Carlo simulations, quantitative agreement with DNA experiments, and the results reconcile this outstanding problem for confined polymers.
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Affiliation(s)
- Liang Dai
- BioSystems and Micromechanics IRG, Singapore-MIT Alliance for Research and Technology Centre, Singapore 117543
| | - Douglas R. Tree
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Johan R. C. van der Maarel
- BioSystems and Micromechanics IRG, Singapore-MIT Alliance for Research and Technology Centre, Singapore 117543
- Department of Physics, National University of Singapore, Singapore 117551
| | - Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Patrick S. Doyle
- BioSystems and Micromechanics IRG, Singapore-MIT Alliance for Research and Technology Centre, Singapore 117543
- Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
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8
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Bhattacharyya P, Cherayil BJ. Chain extension of a confined polymer in steady shear flow. J Chem Phys 2012. [DOI: 10.1063/1.4765295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Reisner W, Pedersen JN, Austin RH. DNA confinement in nanochannels: physics and biological applications. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2012; 75:106601. [PMID: 22975868 DOI: 10.1088/0034-4885/75/10/106601] [Citation(s) in RCA: 246] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
DNA is the central storage molecule of genetic information in the cell, and reading that information is a central problem in biology. While sequencing technology has made enormous advances over the past decade, there is growing interest in platforms that can readout genetic information directly from long single DNA molecules, with the ultimate goal of single-cell, single-genome analysis. Such a capability would obviate the need for ensemble averaging over heterogeneous cellular populations and eliminate uncertainties introduced by cloning and molecular amplification steps (thus enabling direct assessment of the genome in its native state). In this review, we will discuss how the information contained in genomic-length single DNA molecules can be accessed via physical confinement in nanochannels. Due to self-avoidance interactions, DNA molecules will stretch out when confined in nanochannels, creating a linear unscrolling of the genome along the channel for analysis. We will first review the fundamental physics of DNA nanochannel confinement--including the effect of varying ionic strength--and then discuss recent applications of these systems to genomic mapping. Apart from the intense biological interest in extracting linear sequence information from elongated DNA molecules, from a physics view these systems are fascinating as they enable probing of single-molecule conformation in environments with dimensions that intersect key physical length-scales in the 1 nm to 100 µm range.
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Affiliation(s)
- Walter Reisner
- Physics Department, McGill University, Montreal QC, Canada.
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Tree DR, Wang Y, Dorfman KD. Mobility of a semiflexible chain confined in a nanochannel. PHYSICAL REVIEW LETTERS 2012; 108:228105. [PMID: 23003659 PMCID: PMC3503239 DOI: 10.1103/physrevlett.108.228105] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Indexed: 05/14/2023]
Abstract
The classic results of de Gennes and Odijk describe the mobility of a semiflexible chain confined in a nanochannel only in the limits of very weak and very strong confinement, respectively. Using Monte Carlo sampling of the Kirkwood diffusivity with full hydrodynamic interactions, we show that the mobility of a semiflexible chain exhibits a broad plateau as a function of extension before transitioning to an Odijk regime, and that the width of the plateau depends on the anisotropy of the monomers. For the particular case of DNA in a high ionic strength buffer, which has highly anisotropic monomers, we predict that this Rouse-like behavior will be observed over most of the measurable chain extensions seen in experiments.
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Affiliation(s)
- Douglas R. Tree
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455
| | - Yanwei Wang
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-ai Road, Suzhou, 215123, P.R. China
| | - Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455
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Wang Y, Reinhart WF, Tree DR, Dorfman KD. Resolution limit for DNA barcodes in the Odijk regime. BIOMICROFLUIDICS 2012; 6:14101-141019. [PMID: 22299023 PMCID: PMC3269310 DOI: 10.1063/1.3672691] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 12/06/2011] [Indexed: 05/21/2023]
Abstract
We develop an approximation for the probability of optically resolving two fluorescent labels on the backbone of a DNA molecule confined in a nanochannel in the Odijk regime as a function of the fluorescence wavelength, channel size, and the properties of the DNA (persistence length and effective width). The theoretical predictions agree well with equivalent data produced by Monte Carlo simulations of a touching wormlike bead model of DNA in a high ionic strength buffer. Although the theory is only strictly valid in the limit where the effective width of the nanochannel is small compared with the persistence length of the DNA, simulations indicate that the theoretical predictions are reasonably accurate for channel widths up to two-thirds of the persistence length. Our results quantify the conjecture that DNA barcoding has kilobase pair resolution-provided the nanochannel lies in the Odijk regime.
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Affiliation(s)
- Alexander R. Klotz
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
| | - Hugo B. Brandão
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
| | - Walter W. Reisner
- Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8
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Abstract
We have used a realistic model for double stranded DNA and Monte Carlo simulations to compute the extension (mean span) of a DNA molecule confined in a nanochannel over the full range of confinement in a high ionic strength buffer. The simulation data for square nanochannels resolve the apparent contradiction between prior simulation studies and the predictions from Flory theory, demonstrating the existence of two transition regimes between weak confinement (the de Gennes regime) and strong confinement (the Odijk regime). The simulation data for rectangular nanochannels support the use of the geometric mean for mapping data obtained in rectangular channels onto models developed for cylinders. The comparison of our results with experimental data illuminates the challenges in applying models for confined, neutral polymers to polyelectrolytes. Using a Flory-type approach, we also provide an improved scaling result for the relaxation time in the transition regime close to that found in experiments.
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Affiliation(s)
- Yanwei Wang
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455
| | - Douglas R. Tree
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455
| | - Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota — Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455
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Levy SL, Craighead HG. DNA manipulation, sorting, and mapping in nanofluidic systems. Chem Soc Rev 2010; 39:1133-52. [DOI: 10.1039/b820266b] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Okuda S, Inoue Y, Masubuchi Y, Uneyama T, Hojo M. Wall boundary model for primitive chain network simulations. J Chem Phys 2009; 130:214907. [DOI: 10.1063/1.3140941] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jung Y, Jun S, Ha BY. Self-avoiding polymer trapped inside a cylindrical pore: Flory free energy and unexpected dynamics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:061912. [PMID: 19658529 DOI: 10.1103/physreve.79.061912] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Indexed: 05/16/2023]
Abstract
We study the elastic and dynamic behavior of a self-avoiding chain confined inside a cylindrical pore using a Flory-type approach and molecular-dynamics simulations. In the Hookean regime, we find that the effective spring constant of the chain is given by keff approximately N(-1)D(-gamma), where N is the number of monomers and D the diameter of the pore. While the Flory approach reproduces the earlier scaling result gamma=1/3, our simulations confirm a more recent numerical result gamma approximately 0.9 for the computationally accessible regimes. In the absence of hydrodynamic interactions, the relaxation dynamics of a stretched-and-released chain in this regime is characterized by a global relaxation time tauR approximately N2Dgamma with the same exponent gamma for keff. We also discuss how chain relaxation under confinement is influenced by hydrodynamic interactions. In the presence (or absence) of the hydrodynamic interaction, the finite-size effect observed in keff is shown to persist in chain relaxation, resulting in tauR markedly different from previous results.
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Affiliation(s)
- Youngkyun Jung
- Supercomputing Center, Korea Institute of Science and Technology Information, P.O. Box 122, Yuseong-gu, Daejeon 305-806, Korea.
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Affiliation(s)
- Elizabeth A. Strychalski
- Department of Physics, and School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
| | - Stephen L. Levy
- Department of Physics, and School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
| | - Harold G. Craighead
- Department of Physics, and School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
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Soong R, Macdonald PM. Diffusion of PEG confined between lamellae of negatively magnetically aligned bicelles: pulsed field gradient 1H NMR measurements. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:518-527. [PMID: 18095720 DOI: 10.1021/la7022264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The diffusion of various molecular weight poly(ethyleneglycol)s (PEG) confined between the lamellae of magnetically aligned bicelles has been measured using stimulated echo (STE) pulsed field gradient (PFG) 1H nuclear magnetic resonance (NMR) spectroscopy. Bicelles were formulated to contain dimyristoylphosphatidylcholine (DMPC), dimyristoylphosphatidylglycerol (DMPG), and dihexanoylphosphatidylcholine (DHPC) in the proportion DMPG/DMPC = 0.05 and q = (DMPC + DMPG)/DHPC = 4.5. PEG diffusion within the interlamellar spaces between such bicelles was found to be unrestricted over diffusion distances of tens of microns. Two confinement regimes could be differentiated according to the dependence of the reduced PEG diffusivity D/D0, where D0 is the unconfined PEG diffusion coefficient, on the relative confinement Rh/H, where Rh is the unperturbed hydration radius of the particular PEG and H approximately 60 A is the separation between apposing lamellae of the magnetically aligned bicelles. In the regime Rh/H < 0.4, the reduced PEG diffusivity was altered only in proportion to the viscosity increase associated with the bicelle dispersion relative to bulk solution. In the regime Rh/H > 0.4, the reduced PEG diffusivity scaled as (Rh/H)-2/3, in agreement with scaling theories for confined polymers.
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Affiliation(s)
- Ronald Soong
- Department of Chemistry, University of Toronto, Ontario, Canada L5L 1C6
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Balducci A, Mao P, Han J, Doyle PS. Double-Stranded DNA Diffusion in Slitlike Nanochannels. Macromolecules 2006. [DOI: 10.1021/ma061047t] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anthony Balducci
- Department of Chemical Engineering, Department of Mechanical Engineering, and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
| | - Pan Mao
- Department of Chemical Engineering, Department of Mechanical Engineering, and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
| | - Jongyoon Han
- Department of Chemical Engineering, Department of Mechanical Engineering, and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
| | - Patrick S. Doyle
- Department of Chemical Engineering, Department of Mechanical Engineering, and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
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Berk Usta O, Ladd AJC, Butler JE. Lattice-Boltzmann simulations of the dynamics of polymer solutions in periodic and confined geometries. J Chem Phys 2005; 122:094902. [PMID: 15836176 DOI: 10.1063/1.1854151] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A numerical method to simulate the dynamics of polymer solutions in confined geometries has been implemented and tested. The method combines a fluctuating lattice-Boltzmann model of the solvent [Ladd, Phys. Rev. Lett. 70, 1339 (1993)] with a point-particle model of the polymer chains. A friction term couples the monomers to the fluid [Ahlrichs and Dunweg, J. Chem. Phys. 111, 8225 (1999)], providing both the hydrodynamic interactions between the monomers and the correlated random forces. The coupled equations for particles and fluid are solved on an inertial time scale, which proves to be surprisingly simple and efficient, avoiding the costly linear algebra associated with Brownian dynamics. Complex confined geometries can be represented by a straightforward mapping of the boundary surfaces onto a regular three-dimensional grid. The hydrodynamic interactions between monomers are shown to compare well with solutions of the Stokes equations down to distances of the order of the grid spacing. Numerical results are presented for the radius of gyration, end-to-end distance, and diffusion coefficient of an isolated polymer chain, ranging from 16 to 1024 monomers in length. The simulations are in excellent agreement with renormalization group calculations for an excluded volume chain. We show that hydrodynamic interactions in large polymers can be systematically coarse-grained to substantially reduce the computational cost of the simulation. Finally, we examine the effects of confinement and flow on the polymer distribution and diffusion constant in a narrow channel. Our results support the qualitative conclusions of recent Brownian dynamics simulations of confined polymers [Jendrejack et al., J. Chem. Phys. 119, 1165 (2003) and Jendrejack et al., J. Chem. Phys. 120, 2513 (2004)].
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Affiliation(s)
- O Berk Usta
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, USA.
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21
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Jendrejack RM, Schwartz DC, Graham MD, de Pablo JJ. Effect of confinement on DNA dynamics in microfluidic devices. J Chem Phys 2003. [DOI: 10.1063/1.1575200] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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