# Programme

Details on speakers will be added incrementally. Show/hide abstracts by clicking on the talk titles.

The talk schedule can be downloaded as a pdf file here.

Debra J. Bernhardt (Searles) | University of Queensland | Nonequilibrium flow in nanopores (keynote) |

Study of lubrication is an area where changes in behavior due to flow is important. In many cases lubrication occurs at high strain rates and under high confinement. In this work we evaluate the response of a fluid under shear flow in a nanopore. The movement of the boundaries in opposite directions induces the shear. The viscous heat generated inside the pore is removed by a thermostat applied exclusively to the atomic walls, leaving the dynamics of the fluid as realistic as possible. [3,4] We will also discuss the characterization of slip in these small pores. [1] D. J. Evans, D. J. Searles and S. R. Williams, J. Chem. Phys; 128, 014506 (2008). [2] S. J. Brookes, J. C. Reid, D. J. Evans and D. J. Searles, Journal of Physics: Conference Series297, 012017 (2011). [3] S. Bernardi, S. J. Brookes, D. J. Searles and D. J. Evans, Journal of Chemical Physics, 137, 074114 (2012). [4] S. Bernardi and D. J. Searles, Molecular Simulation, doi: 10.1080/08927022.2015.1049174, accepted (May 2015). | ||

Gary Bryant | RMIT University | Synchrotron SAXS and Neutron studies of Structure Factors in Hard Sphere Suspensions |

Pierluigi Cesana | Kyushu University (Australia Branch) | Effective response of elastic liquid crystal membranes |

For NEs in the thin membrane limit, an interplay of material and structural non-linearities is observed. These membranes can display fine-scale features both due to wrinkling that one expects in thin elastic membranes and due to oscillations of the local optical axis that one expects in liquid crystal elastomers. In this talk I will present an energy-minimization approach based on homogenization to describe the effective energy density of thin membranes of liquid crystal elastomers by providing a detailed characterization of the fine-scale features. If time allows, I will show how to model the space-time evolution of a microstructure as a Branching Random Walk process. This modeling work is inspired by experimental investigation of the jerky character of martensitic transformations occurring in shape memory alloys. Comparisons are reported for numerical and analytical solutions and experimental observations. | ||

Derek Chan | University of Melbourne and Swinburne University of Technology | Modelling the collision between a rising bubble and a deformable flat interface |

A continuum model with no adjustable parameters has been developed that is able to predict collision and bounces observed for such bubble interaction in water and in alcohol. The ability to predict the terminal velocity accurate is an important pre-requisite in obtaining good quantitative agreement between theoretical predictions and experimental results. | ||

Nathan Clisby | University of Melbourne | Monte Carlo simulation of polymers attached to a surface |

Peter Daivis | RMIT University | Nonlocal constitutive equations for shear flow in fluids with strongly inhomogeneous density and velocity profiles |

Sergio De Luca | UNSW | Studying of the anticancer drugs - Dendrimer interactions: a molecular dynamics approach |

Peptide dendrimers are macromolecules with the structure composed of branches and a core formed by amino acids linked via peptide/amide bonds. The dendrimers studied here were synthesized and used to understand the solubility, permeability and deposition of anticancer drugs such as 5-Fluorouracil through the skin. The experimental data have demonstrated that the solubility of drugs in water and its permeability across the human epidermis is improved when used in conjunction with peptide dendrimers. | ||

Ian Douglass | University of Sydney | The role of particle softness in amorphous atomic alloys |

Denis J Evans | ANU | Dissipation and the Foundations of Classical Statistical Thermodynamics (keynote) |

References 1. Evans DJ and Searles DJ, The fluctuation theorem, Advances in Physics, 2002, 51,1529-1585. 2. Evans DJ, Searles DJ and Williams SR, On the fluctuation theorem for the dissipation function and its connection with response theory J. Chem. Phys. 2008, 128, 014504, ibid, 2008, 128, 249901 3. Evans DJ, Searles DJ and Williams SR, Dissipation and the relaxation to equilibrium, J. Stat. Mech., 2009, P07029 4. Reid JC, Williams SR, Searles DJ, Rondoni L and Evans DJ, Fluctuation relations and the foundations of statistical thermodynamics: A deterministic approach and numerical demonstration, Nonequilibrium Statistical Physics of Small Systems: Fluctuation Relations and Beyond, Editors R. Klages, W. Just, C. Jarzynski, 2013 Wiley-VCH, 57-82. | ||

Kirill Glavatskiy | University of Queensland | Is local equilibrium sufficient for irreversible systems with delayed response? |

In this talk we address this question by suggesting a variational formulation of irreversible evolution of a system with non-zero thermodynamic inertia. We introduce the Lagrangian, which depends on the properties of the normal and the so-called "mirror-image" systems. We show that the standard evolution equations, in particular the Maxwell-Cattaneo-Vernotte equation, can be derived from the variational procedure without going beyond the assumption of local equilibrium. We also argue, that the second law of thermodynamics in non-equilibrium should be understood as a consequence of the variational procedure and the property of local equilibrium. For systems with instantaneous response this leads to the standard requirement of the local instantaneous entropy production being always positive. However, if a system is characterized by delayed response, the formulation of the second law of thermodynamics should be altered. In particular, the quantity, which is always positive, is not the instantaneous entropy production, but the entropy production averaged over a proper time interval. | ||

Marsel Gokovi | Griffith University | Mass transport rates in confined spaces |

Stephen Hannam | RMIT University | Molecular dynamics calculations of intermediate scattering functions for a model colloidal fluid with explicit solvent. |

As a complement to light scattering experimental results, Molecular Dynamics (MD) simulation was used to study a model colloidal suspension at a range of concentrations from the dilute limit up to the freezing point. We modelled the colloidal particles with a Weeks-Chandler-Anderson (WCA) potential modified to include a hard-core, while the solvent was a simple WCA fluid. The colloid/solvent size ratio was set to 4.03:1 and the mass ratio was 50:1. In order to remove strong depletion effects inherent in binary systems with comparable size ratios, modified colloid-solvent interaction parameters were used. With the modified interaction parameters the liquid structure, phase behavior and crystal structure were shown to match experimental and theoretical HS systems. [2] To study the dynamical behavior of the model, the velocity autocorrelation function was computed and was shown to exhibit behavior which matches experimental results more closely than the single component HS model (i.e. velocity reversals at low concentrations).[2] The intermediate scattering functions were calculated over the same range of concentrations giving results in good agreement with light scattering experiments. [1] P. N. Pusey and W. van Megen, Nature London 320, 340 (1986). [2] W. van Megen and S. M. Underwood, Nature London 362, 616 (1993). [3] S. D. W. Hannam, P. J. Daivis and G. Bryant, Molecular Simulation (2015). | ||

Peter Harrowell | University of Sydney | The Statistical Mechanics of Liquid Structure |

1. P. Ronceray and P. Harrowell, Soft Matt. 11, 3322 (2015) | ||

Emma Hodges | Monash University | Fluctuation theorems to probe equilibrium properties of non-equilibrium work trajectories using simulation |

David Huang | University of Adelaide | Surface effects in nanofluidic energy harvesting (keynote) |

Ahmad Jabbarzadeh | University of Sydney | Surface Induced Crystallization of Polymers |

Ravi Jagadeeshan | Monash University | Coil-stretch hysteresis in polymer solutions |

Matthew King | Griffith University | Chaos and fluctuations in a modified Ehrernfest wind-tree model |

Joint work with Owen Jepps | ||

Naida M. Lacevic | University of Melbourne | Viscoelasticity of glycerol at ultra-high frequencies investigated via molecular dynamics simulations |

This is joint work with John E. Sader. | ||

Daniel R. Ladiges | University of Melbourne | Frequency-domain Monte Carlo method for oscillatory gas flows |

Joint work with John E. Sader | ||

Lang Liu | University of Queensland | Interfacial resistance and size-dependent transport coefficients in nanoporous materials |

We investigate the internal and external resistances to transport of CH4 in finite length CNTs having the diameter of 1.36nm, at ambient temperature, considering also an external bulk region. It is found that overall transport coefficients of CH4 are 2-3 orders of magnitude lower than the corresponding values for infinitely long CNTs. We determine the interfacial resistance using the one-way flux method4, and extract the size-dependent intra-crystalline resistance from the overall resistance using our novel technique. We find that while the interfacial resistance is independent of CNT length, the intra-crystalline resistance per unit length is a decreasing function of length. Consequently, the internal diffusivity of CH4 increases with increase in CNT length. However, the ratio of interfacial resistance to the overall resistance is an increasing function of pressure, and is close to 25% for CH4 at 15 bar in a 50 nm long (10,10) CNT. Joint work with Suresh Bathia. 1 Newsome, D. A.; Sholl, D. S. Nano Letters 2006, 6, 2150- 2153. 2 Arya, G.; Maginn, E. J.; Chang, H.-C. J. Phys. Chem. B 2001, 105, 2725-2735. 3 Zimmermann, N. E.; Smit, B.; Keil, F. J. J. Phys. Chem. C 2012, 116, 18887-18883. 4 Newsome, D. A.; Sholl, D. S. J. Phys. Chem. B 2005, 109, 7237-7244. | ||

Adrian Menzel | RMIT University | Planar Poiseuille flow of highly confined polymer solutions |

Guy Metcalfe | Swinburne University of Technology and Monash University | Entropy Production, Fluctuations and the Slow Approach to Equilibrium in a Mechanical Analogue to Soft Matter: the Soft Billiard |

Gerald Pereira | CSIRO | Brazil nuts and more |

Mihail N. Popescu | Max Planck Institute for Intelligent Systems | Effective interaction between active colloids and fluid interfaces |

There are many application relevant cases in which the suspension containing active colloids is bounded by a fluid-fluid interface, and thus the colloidal particles may reside in the vicinity of the interface or get near the interface during their motion. Here we present theoretical evidence that, in such a case, chemically active (or locally heated) spherical particles experience a very strong, long-ranged effective force field due to the Marangoni stresses self-induced at the interface. This force of hydrodynamic origin gives rise to a drift of the particle towards or away from the fluid interface (depending only on how the tensioactive agent affects the interface) on time scales which can be orders of magnitude shorter than those associated with Brownian diffusion. In particular, this can facilitate significantly the process of particle adsorption towards the interface and therefore has potentially important implications for, e.g., the subsequent self-assembly of particles at fluid--fluid interfaces. | ||

Andrey Pototsky | Swinburne University of Technology | Instability modes and regular density patterns in a colony of self-propelled surfactant particles covering a thin liquid layer |

Prabhakar Ranganathan | Monash University | The mechanobiology of construction and operation of traffic networks in interstitial swarms of bacteria |

A generic moving interface model is proposed to explore the interplay between cell motility, active forcing, and mechanical interfacial interactions with a passive medium. The model accounts for the dynamics of nematic orientation of the rod-shaped active particles at the interface. A fingering instability of the edge of the active monolayer as it ploughs its way through the soft substrate could explain the emergence of cell rafts. The merging of rafts and the prevention of cells from aligning perpendicular to trench walls in the colony interior leads to colony morphologies similar to those observed in the experiments. The moving interface model may also be applied to other biological systems such as cytoskeletal-membrane interactions. | ||

Shibu Saw | University of Sydney | Rigidity of matter as a consequence of configurational constraint |

Qiang Sun | University of Melbourne | Boundary regularised integral equation formulation of the Debye-Hückel model |

Andrew Tarzia | University of Adelaide and CSIRO | Design Principles for the Self-Assembly of Porous Materials |

Maryna Vlasiuk | Swinburne University of Technology | Molecular simulation of the thermodynamic properties of liquid neon |

In our study we use intermolecular potentials of different origins and quality. These are two accurate ab initio potentials [3,4], an empirical potential derived for noble gases [5] but not specifically for neon, and a simple Lennard-Jones model, which we use as a reference. To account for quantum effects we follow the approach introduced by Feynman and Hibbs [6] and employ the quantum effective potentials. We run a number of Monte Carlo simulations in the canonical ensemble [7] for generating our results. For calculating thermodynamic properties (heat capacities, compressibilities, speed of sound, etc.) we use Lustig's formalism [8]. Our study demonstrates that the empirical BFW potential [5] with quantum cor- rection achieves the best agreement with experimental data, surpassing the accuracy of `tailor-made' ab initio potentials. [1] J. D. Boer. Physica, 14:139, 1948. [2] P. D. Neufeld and R. A. Aziz. J. Chem. Phys., 59:2234, 1973. [3] R. Eggenberger, S. Gerber, et al. Mol. Phys., 82:689, 1994. [4] K. Leonhard and U. K. Deiters. Mol. Phys., 98(20):1603-1616, 2000. [5] J. A. Barker, R. A. Fisher, et al. Mol. Phys., 21:657, 1971. [6] R. P. Feynman and A. R. Hibbs. Quantum Mechanics and Path Integrals. McGraw- Hill: New York, 1965. [7] R. J. Sadus. Molecular Simulation of Fluids: Theory, Algorithms, and Object- orientation. Elsevier, Amsterdam, 1999. [8] R. Lustig. Mol. Sim., 37(6):457-465, 2011. | ||

Brad Wells | CSIRO | Towards developing structure-property relationships for tactic methacrylic ester polymers |

In this paper some preliminary results in attempting to determine structure-property relationships for the methacrylate ester polymers are presented. A particular focus of this work is in determining how the tacticity of the polymer chains can be included in the descriptive model. To investigate the structure property-relationships of the polymers a multi-scale simulation approach is employed, utilising simulations based both on density functional theory and empirical potentials. Some factors that influence bulk properties of the polymers, such as the glass transition temperature are discussed. | ||

David Williams | ANU | The Physics of Threading Rotaxanes and Nanotubes |

Here we will examine one of the more fundamental problems: How does a rod thread a ring or tube? We will show that event, which is governed by translational and orientational entropy, is in almost all cases of practical interest very rare. The probability obeys simple power laws based on the geometry of the rod/ring/tube system. This work has applications to other areas (polymer translocation, threading of nanotubes), where threading is of importance. | ||

Stephen R. Williams | ANU | Beyond Thermodynamics: Totally Nonequilibrium Relaxation towards Equilibrium |

William van Megen | RMIT University | Exposing a dynamical signature of the freezing transition through the sound propagation gap |