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Dr Daniel J Read

Reader
Applied Mathematics

Contact details

Room: Satellite 10.23
Tel: +44 (0)113 3435179
Email: D.J.Read @ leeds.ac.uk

Keywords

Polymer
Rheology
Tube model
Branched polymer reactions
Stochastic physics
Coarse graining proteins

Research interests

I am part of the Polymers and Industrial Mathematics group. My main research interests are in the fields of theoretical polymer physics, rheology and coarse grained modelling of biological molecules. I'm involved in the SUPOLEN Marie Curie Initial training network, and in the Soft Matter and Functional Interfaces Centre for Doctoral Training (SOFI CDT).

Polymer dynamics and rheology

Polymers are long molecules made from joining together lots of small molecules (or monomers). Sometimes polymer molecules are linear, but very often - notably in the case of Low Density Polyethylene (LDPE) used to make plastic bottles - they include many branches.

During the manufacture of polymeric (or plastic) materials and commodities, liquids containing polymers are subjected to flow. The way these liquids react is determined by the shapes, or configurations that the molecules adopt. Polymer molecules behave like springs, and become stretched by the flow, giving rise to the strongly elastic behaviour of polymeric fluids. The study of the dynamics of polymer molecules is very important for the understanding of flow of polymeric fluids.

If polymer molecules overlap sufficiently, then they get tangled up (like spaghetti) so that they are constrained in their movement. The "tube model" for entangled polymers provides a conceptual framework for understanding the constrained motion, and for making mathematical predictions about the polymers' response to flow.

Branchpoints in the polymer molecules provide addtional obstacles to the motion of entangled polymers, so that the distribution of branchpoints in polymer molecules can be a critical factor in determining flow properties.

Coarse-grained dynamics of globular proteins

In collaboration with Dr Sarah Harris (Physics) and Dr Oliver Harlen (Mathematics) I am developing methods for simulating coarse-grained dynamics of globular proteins. Full Molecular Dynamics simulations are computationally expensive and typically generate around 50 nanoseconds of simulation time without too much difficulty. However, the timescale of biological events for example in protein

folding can be on the order of microseconds to milliseconds. In response to these problems, there are a wide variety of coarse graining techniques used to

try to bridge this timescale gap and simulate larger systems. These include go-model, coarse grained force fields such as the Martini force field, Elastic Network Models , dissipative particle dynamics, etc. We are pursuing an alternative approach, in which the protein is treated as a viscoelastic continuum with material properties which vary as a function of position. We simulate this using finite element analysis, incorporating stochastic thermal noise.

Reaction chemistry and branched polymer architecture

There are different chemical routes used to produce branched polymers in an industrial setting. The particular reaction chemistry, and the reactor type and conditions, have a large effect on the number and distribution of branches throughout the polymer molecules.

As an example of this, metallocene catalysts form branches via the formation of "macromomonomers" (chains with double-bonds at the end) and the incorporation of these into growing chains. Based on this simple mechanism, it is possible to derive mathematically the distributions of molecular size and branching.

One can extend these ideas to treat situations where there are several types of metallocene catalysts, or different reactor conditions, or different reaction chemistry (e.g. LDPE is usually manufactured via a free-radical chemistry which gives branching via an entirely different mechanism). The goal is an understanding of how chemistry affects branching, and how this in turn affects the flow properties of polymers.

Polymer dynamics and neutron scattering

It is important to understand the shapes, or conformations that polymers take under flow conditions. Although polymer rheology (the stress response of the fluid) is one way of probing this, it is important to have other independent tools to check that the theory is right. A more direct measure of polymer shape is obtained via neutron scattering.

Polymer molecules can be wholly, or partially "labelled" by replacing hydrogen atoms in the molecules with deuterium. Neutrons interact with deutrium differently to hydrogen, so that a beam of neutrons passing through a labelled melt of polymers will be scattered. The intensity, and angle, of scattering is related to polymer shapes. Comparison of calculated scattering (based on models for polymer motion) with experiments allows us to learn more about the mechanisms of polymer relaxation.

Useful links

SUPOLEN Marie Curie Initial Training Network
Soft Matter and Functional Interfaces CDT

Current postgraduate students

Victor Boudara (2013)

Publications

Shivokhin ME, Read DJ, Kouloumasis D, Kocen R, Zhuge F, Bailly C, Hadjichristidis N, Likhtman AE Understanding Effect of Constraint Release Environment on End-to-End Vector Relaxation of Linear Polymer Chains Macromolecules, 50, 4501-4523, 2017
DOI:10.1021/acs.macromol.6b01947
View abstract

Das C, Read DJ, Soulages JM, Shirodkar PP Static and Dynamic Scaling Close to Gelation in Chain-Polymerization: Effect of Reactor Type Macromolecular Theory and Simulations, 26, 2017
DOI:10.1002/mats.201700006
View abstract

Boudara VAH, Read DJ Stochastic and preaveraged nonlinear rheology models for entangled telechelic star polymers Journal of Rheology, 61, 339-362, 2017
DOI:10.1122/1.4974908
View abstract

Hawke LGD, Huang Q, Hassager O, Read DJ Modifying the pom-pom model for extensional viscosity overshoots Journal of Rheology, 59, 995-1017, 2015
DOI:10.1122/1.4922060
View abstract

Solernou A; Harris SA; Harlen OG; Read DJ; Smith KA; Muench SP Understanding fibrin protofibrils at the molecular level: formation and flexibility through a new coarse-grained protein modelling approach, 839-839 2015

Hanson B, Richardson R, Oliver R, Read DJ, Harlen O, Harris S Modelling biomacromolecular assemblies with continuum mechanics Biochemical Society Transactions, 43, 186-192, 2015
DOI:10.1042/BST20140294
View abstract

Harris SA, Hanson B, Richardson R, Read DJ, Harlen OG Mesoscale Modelling of Biomolecules using Continuum Mechanics BIOPHYSICAL JOURNAL, 108, 183A-183A, 2015

Read DJ From reactor to rheology in industrial polymers Journal of Polymer Science, Part B: Polymer Physics, 53, 123-141, 2015
DOI:10.1002/polb.23551
View abstract

Gray A, Harlen OG, Harris SA, Khalid S, Leung YM, Lonsdale R, Mulholland AJ, Pearson AR, Read DJ, Richardson RA In pursuit of an accurate spatial and temporal model of biomolecules at the atomistic level: A perspective on computer simulation Acta Crystallographica Section D: Biological Crystallography, 71, 162-172, 2015
DOI:10.1107/S1399004714026777
View abstract

Richardson RA, Papachristos K, Read DJ, Harlen OG, Harrison M, Paci E, Muench SP, Harris SA Understanding the apparent stator-rotor connections in the rotary ATPase family using coarse-grained computer modeling. Proteins, 82, 3298-3311, 2014
DOI:10.1002/prot.24680
View abstract

Lentzakis H, Das C, Vlassopoulos D, Read DJ Pom-pom-like constitutive equations for comb polymers Journal of Rheology, 58, 1855-1875, 2014
DOI:10.1122/1.4895606
View abstract

Das C, Read DJ, Soulages JM, Shirodkar PP Modeling of synthesis and flow properties of propylene-diene copolymers Macromolecules, 47, 5860-5868, 2014
DOI:10.1021/ma5011205
View abstract

Oliver R, Richardson RA, Hanson B, Kendrick K, Read DJ, Harlen OG, Harris SA Modelling the dynamic architecture of biomaterials using continuum mechanics In Protein Modelling, 175-197, 2014
DOI:10.1007/978-3-319-09976-7_8
View abstract

Bačová P, Lentzakis H, Read DJ, Moreno AJ, Vlassopoulos D, Das C Branch-point motion in architecturally complex polymers: estimation of hopping parameters from computer simulations and experiments Macromolecules, 2014
DOI:10.1021/ma5003936
View abstract

Das C, Read DJ, Auhl D, Kapnistos M, den Doelder J, Vittorias I, McLeish TCB Numerical prediction of nonlinear rheology of branched polymer melts Journal of Rheology, 58, 737-757, 2014
DOI:10.1122/1.4869485
View abstract

Bačová P, Hawke LGD, Read DJ, Moreno AJ Dynamics of branched polymers: A combined study by molecular dynamics simulations and tube theory Macromolecules, 46, 4633-4650, 2013
DOI:10.1021/ma4005988
View abstract

Oliver R, Read DJ, Harlen OG, Harris SA A Stochastic Finite Element Model for the Dynamics of Globular Macromolecules Journal of Computational Physics, 239, 147-165, 2013
DOI:10.1016/j.jcp.2012.12.027
View abstract

Lentzakis H, Vlassopoulos D, Read DJ, Lee H, Chang T, Driva P, Hadjichristidis N Uniaxial extensional rheology of well-characterized comb polymers Journal of Rheology, 57, 605-625, 2013
DOI:10.1122/1.4789443
View abstract

Hutchings LR, Kimani SM, Hoyle DM, Read DJ, Das C, McLeish TCB, Chang T, Lee H, Auhl D In Silico Molecular Design, Synthesis, Characterization, and Rheology of Dendritically Branched Polymers: Closing the Design Loop (vol 1, pg 404, 2012) ACS MACRO LETTERS, 1, 742-742, 2012
DOI:10.1021/mz300263m

Hutchings LR, Kimani SM, Hoyle DM, Read DJ, Das C, McLeish TCB, Chang T, Lee H, Auhl D In Silico Molecular Design, Synthesis, Characterization, and Rheology of Dendritically Branched Polymers: Closing the Design Loop ACS MACRO LETTERS, 1, 404-408, 2012
DOI:10.1021/mz300059k

Read DJ, Jagannathan K, Sukumaran SK, Auhl D A full-chain constitutive model for bidisperse blends of linear polymers Journal of Rheology, 2012
View abstract

Read DJ, Auhl D, Das C, den Doelder J, Kapnistos M, Vittorias I, McLeish TCB Linking models of polymerization and dynamics to predict branched polymer structure and flow. Science, 333, 1871-1874, 2011
DOI:10.1126/science.1207060
View abstract

Nayak K, Read DJ, McLeish TCB, Hine PJ, Tassieri M A Coarse-Grained Molecular Model of Strain-Hardening for Polymers in the Marginally Glassy State J POLYM SCI POL PHYS, 49, 920-938, 2011
DOI:10.1002/polb.22263

den Doelder J, Das C, Read DJ Exploration of branching topology effects on polymer melt rheology using hierarchical calculation schemes RHEOL ACTA, 50, 469-484, 2011
DOI:10.1007/s00397-011-0547-0

Auhl D, Chambon P, McLeish TCB, Read DJ Elongational Flow of Blends of Long and Short Polymers: Effective Stretch Relaxation Time PHYS REV LETT, 103, 2009
DOI:10.1103/PhysRevLett.103.136001

Read DJ, Jagannathan K, Likhtman AE Entangled polymers: Constraint release, mean paths, and tube bending energy MACROMOLECULES, 41, 6843-6853, 2008
DOI:10.1021/ma8009855

Read DJ, Das C, Kapnistos M, McLeish TCB Predicting the non-linear rheology of multiply and randomly branched entangled polymer melts American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 49, 75-76, 2008

Chambon P, Fernyhough CM, Im K, Chang TY, Das C, Embery J, McLeish TCB, Read DJ Synthesis, temperature gradient interaction chromatography, and rheology of entangled styrene comb polymers MACROMOLECULES, 41, 5869-5875, 2008
DOI:10.1021/ma800599m

Read DJ; Das C; Kapnistos M; McLeish TC POLY 215-Predicting the nonlinear rheology of multiply and randomly branched entangled polymer meltsABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 2008

Read DJ; Das C; Kapnistos M; Auhl D; Den Doelder J; Vittorias I; McLeish TCB From reactor to rheology in LDPE modelingAIP CONF PROC, 424-426 2008
View abstract

Hine PJ, Duckett A, Read DJ Influence of molecular orientation and melt relaxation processes on glassy stress-strain behavior in polystyrene MACROMOLECULES, 40, 2782-2790, 2007
DOI:10.1021/ma062474+

Teixeira PIC, Read DJ, McLeish TCB Demixing instability in coil-rod blends undergoing polycondensation reactions J CHEM PHYS, 126, 2007
DOI:10.1063/1.2437200

Hine PJ, Duckett RA, Read DJ Influence of Molecular Orientation and Melt Relaxation Processes on Glassy Stress-Strain Behavior in Polystyrene Macromolecules, 40, 2782-2790, 2007

Kunamaneni S, Buzza DMA, Read DJ, Parker D, Kenwright AM, Feast WJ, Larsen AL Entanglement transition of randomly branched polymers in the hyperbranched class MACROMOLECULES, 39, 6720-6736, 2006
DOI:10.1021/ma0603276

Inkson NJ, Das C, Read DJ Monte Carlo simulation for the structure of polyolefins made with two metallocene catalysts in a batch reactor MACROMOLECULES, 39, 4920-4931, 2006
DOI:10.1021/ma060654d

Das C, Read DJ, Kelmanson MA, McLeish TCB Dynamic scaling in entangled mean-field gelation polymers PHYS REV E, 74, 2006
DOI:10.1103/PhysRevE.74.011404

Graham RS, Bent J, Hutchings LR, Richards RW, Groves DJ, Embery J, Nicholson TM, McLeish TCB, Likhtman AE, Harlen OG, Read DJ, Gough T, Spares R, Coates PD, Grillo I Measuring and predicting the dynamics of linear monodisperse entangled polymers in rapid flow through an abrupt contraction. A small angle neutron scattering study MACROMOLECULES, 39, 2700-2709, 2006
DOI:10.1021/ma052357z

Das C, Inkson NJ, Read DJ, Kelmanson MA, McLeish TCB Computational linear rheology of general branch-on-branch polymers Journal of Rheology, 50, 207-235, 2006
DOI:10.1122/1.2167487
View abstract

Patil R, Colby RH, Read DJ, Chen GH, Guan ZB Rheology of polyethylenes with novel branching topology synthesized by a chain-walking catalyst MACROMOLECULES, 38, 10571-10579, 2005
DOI:10.1021/ma051408p

Blanchard A, Graham RS, Heinrich M, Pyckhout-Hintzen W, Richter D, Likhtman AE, McLeish TCB, Read DJ, Straube E, Kohlbrecher J Small angle neutron scattering observation of chain retraction after a large step deformation PHYS REV LETT, 95, 2005
DOI:10.1103/PhysRevLett.95.166001

Heinrich M, Pyckhout-Hintzen W, Allgaier J, Richter D, Straube E, McLeish TCB, Wiedenmann A, Blackwell RJ, Read DJ Small-angle neutron scattering study of the relaxation of a melt of polybutadiene H-polymers following a large step strain MACROMOLECULES, 37, 5054-5064, 2004
DOI:10.1021/ma0304372

Read DJ Calculation of scattering from stretched copolymers using the tube model: Incorporation of the effect of elastic inhomogeneities MACROMOLECULES, 37, 5065-5092, 2004
DOI:10.1021/ma030438u

Read DJ Convective constraint release with chain stretch: solution of the Rouse-tube model in the limit of infinite tubes Journal of Rheology, 48, 349-377, 2004
DOI:10.1122/1.1645515

Everitt SL, Harlen OG, Wilson HJ, Read DJ Bubble dynamics in viscoelastic fluids with application to reacting and non-reacting polymer foams Journal of Non-Newtonian Fluid Mechanics, 114, 83-107, 2003
DOI:10.1016/S0377-0257(03)00108-3
View abstract

Read DJ; McLeish TCB; Heinrich M; Pyckhout-Hintzen W; Allgaier J; Richter D Elastic inhomogeneities in branched polymer melts as revealed by neutron scattering.ABSTR PAP AM CHEM S, U388-U388 2003

Bent J, Hutchings LR, Richards RW, Gough T, Spares R, Coates PD, Grillo I, Harlen OG, Read DJ, Graham RS, Likhtman A, Groves DJ, Nicholson TM, McLeish TCB Neutron-Mapping Polymer Flow: Scattering, Flow Visualization, and Molecular Theory Science, 301, 1691-1695, 2003
DOI:10.1126/science.1086952

de Gennes PG, Doi M, Magerle R, Semenov AN, Read DJ, Cates ME, Zheng XH Molecular modelling of entanglement - Discussion PHILOS T ROY SOC A, 361, 651-652, 2003

Doi M, Takimoto JI, De Gennes PG, Magerle R, Semenov AN, Read DJ, Cates ME, Zheng XH Molecular modelling of entanglement Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 361, 641-652, 2003
DOI:10.1098/rsta.2002.1168
View abstract

Read DJ, Soares JBP Derivation of the distributions of long chain branching, molecular weight, seniority, and priority for polyolefins made with two metallocene catalysts Macromolecules, 36, 10037-10051, 2003
DOI:10.1021/ma030354l

Read DJ Letter to the editor: Comment on "Quantitative assessment of strain-hardening of LDPE melts by MSF model" [J.Rheol. 47, 779-793 (2003)] Journal of Rheology, 47, 1311-1312, 2003
DOI:10.1122/1.1603243

Heinrich M, Pyckhout-Hintzen W, Allgaier J, Richter D, Straube E, Read DJ, McLeish TCB, Groves DJ, Blackwell RJ, Wiedenmann A Arm relaxation in deformed H-polymers in elongational flow by SANS MACROMOLECULES, 35, 6650-6664, 2002
DOI:10.1021/ma011923x

Read DJ, Teixeira PIC, Duckett RA, Sweeney J, McLeish TCB Theoretical and finite-element investigation of the mechanical response of spinodal structures European Physical Journal E: Soft Matter, 8, 15-31, 2002

Wallace EJ, Buzza DMA, Read DJ Monte carlo simulation scheme for dendrimers satisfying detailed balance MACROMOLECULES, 34, 7140-7146, 2001

Mao Y, McLeish TCB, Teixeira PIC, Read DJ Asymmetric landscapes of early spinodal decomposition EUR PHYS J E, 6, 69-77, 2001

Read DJ, McLeish TCB Molecular Rheology and Statistics of Long Chain Branched Metallocene-Catalyzed Polyolefins Macromolecules, 34, 1928-1945, 2001
DOI:10.1021/ma001483u

Wallace EJ, Buzza DMA, Read DJ Monte Carlo Simulation Scheme for Dendrimers Satisfying Detailed Balance Macromolecules, 34, 7140-7146, 2001
DOI:10.1021/ma0104130

Read DJ, Teixeira PIC, McLeish TCB Demixing instability in polymer blends undergoing polycondensation reactions Macromolecules, 33, 3871-3878, 2000

Read DJ Calculation of Scattering from Stretched Copolymers Using the Tube Model: a Generalisation of the RPA European Physical Journal B. Condensed Matter, 12, 431-449, 1999
View abstract

Read DJ, Duckett RA, Sweeney J, McLeish TCB The Chevron Folding Instability in Thermoplastic Elastomers and Other Layered Materials Journal of Physics D: Applied Physics, 32, 2087-2099, 1999
View abstract

McLeish TCB, Allgaier JB, Bick DK, Bishko G, Biswas P, Clarke N, Groves DJ, Hakiki A, Heenan R, Johnson JM, Kant R, Read DJ, Young RN Dynamics of Entanged H-Polymers: Theory, Rheology and Neutron-Scattering Macromolecules, 32, 6734-6758, 1999

Read DJ, McLeish TCB Read and McLeish Reply: Physical Review Letters, 80, 5450-5450, 1998
DOI:10.1103/PhysRevLett.80.5450

Read DJ Mean Field Theory for Phase Separation During Polycondensation Reactions and Calculation of Structure Factors for Copolymers of Arbitrary Architecture Macromolecules, 31, 899-911, 1998
View abstract

Read DJ, McLeish TCB Microscopic theory for the ''lozenge'' contour plots in scattering from stretched polymer networks Macromolecules, 30, 6376-6384, 1997

Read DJ, McLeish TCB "Lozenge" Contour Plots in Scattering from Polymer Networks Physical Review Letters, 79, 87-90, 1997
View abstract

Read DJ, McLeish TCB Microscopic Theory for the 'Lozenge' Contour Plits in Scattering from Stretched Polymer Networks Macromolecules, 30, 6376-6384, 1997

Read DJ, McLeish TCB Microscopic theory for the "lozenge" contour plots in scattering from stretched polymer networks Macromolecules, 30, 6376-6384, 1997