Invited Speakers

Dynamics of ring polymers by neutron scattering: overview and recent developments
Professor Valeria Arrighi, Heriot-Watt University, UK

Abstract

TBC

Bio

Valeria graduated in Pure Chemistry from the University of Padova, and received her PhD in Polymer Science in 1992 from Imperial College London. Following a postdoctoral fellowship also at Imperial, she joined the faculty at Heriot-Watt University, Edinburgh, in 1996. Her research focuses on the molecular-level study of polymer structure and dynamics, employing extensive neutron scattering and spectroscopy methods. Her group elucidates physical properties such as conformation, topology and orientational order in model polymer nanocomposites and membranes for water purification, and establishes fundamental correlations with material performance.


How to tune properties of interfaces with polymers; insight from molecular simulation
Professor Paola Carbone
, University of Manchester, UK

Abstract

The prediction of the adsorption and dynamic properties of polymers at solid and soft interfaces is an important technological and biological problem. Solid interfaces are indeed present in all polymer composites (where particles are dispersed into a polymeric matrix with the aim of improving its mechanical and rheological properties) but also relevant for many applications such as for coating. Polymers adsorb also at liquid interfaces in many industrial processes, such as liquid/liquid extractions, solvent displacement methods, or emulsifications, and also when used for biological applications, such as drug nanocarriers, biocompatibilizers, or protective coatings.

In this talk we will show how multiscale modelling can help in predicting the adsorption properties of polymers at solid surfaces (specifically carbon black) and soft interfaces (liquid/liquid). We will clarify the thermodynamic of adsorption and how the properties of the interface as well as of the bulk polymer change upon adsorption.

Bio

Paola obtained her PhD in Materials Science in 2004, followed by a postdoc at the University of Bologna, and a Humboldt Foundation fellowship at the Technical University of Darmstadt. She was awarded an RCUK fellowship and joined the University of Manchester in 2008. Paola’s research focuses on soft matter simulations, and her group specialises in developing new multiscale coupling procedures to link different modelling techniques from quantum mechanics to dissipative particle dynamics. Currently active research areas are: electrolyte/graphene interfaces, polymer composites for industrial applications and surfactant solutions. 


Quantifying the length-scales of polymer-substrate interactions and the impact on physical properties of polymers
Professor Peter Green, University of Michigan, USA

Abstract

It is well understood that under confinement, typically for length scales on the order of a nanometer to tens of nanometers, polymers exhibit physical properties that manifest the influence of entropic affects and of interactions between polymer chain segments and external interfaces. Physical properties, including glass transition temperatures (Tg), chain dynamics, physical aging rates, mechanical moduli, thermal conductivities and charge carrier mobilities are well documented to exhibit film thickness (h) dependent behavior. Three topics will be discussed in this presentation. (1) The origins of the film thickness dependencies of these different physical properties will be briefly explained.  (2) Macromolecular architecture, linear chain or multi arm star-shaped, strongly influences the magnitudes of the thickness dependencies of the Tgs and the physical aging rates of polymers.  The transitions from linear-chain, to star-like, to colloidal-like behavior will be explained. (3) Different experimental techniques -incoherent neutron scattering, spectroscopic ellipsometry and broad band dielectric spectroscopy -are known to yield Tgs of different magnitudes and, in some cases different h-dependent trends, for the same polymer thin film/substrate systems. While these techniques rely on different observables that denote the transition, the origins of these discrepancies  remain a matter of debate. It will be shown how insights based on the first quantitative measurements of the strengths and length-scales of the interactions at the buried interfaces between different polymers and a substrate, using kelvin force microscopy, provide a pathway to reconcile these apparent discrepancies.

Bio

Peter graduated from Hunter College and obtained his MS and PhD from Cornel University (1985). He joined Sandia National Laboratories, and then the faculty at the University of Texas at Austin (1996), later moving to the University of Michigan in 2005 to chair the Department of Materials Science and Engineering. He became deputy laboratory director, Science and Technology, and chief research officer at the National Renewable Energy Laboratory (NREL) in 2016. Peter is the recipient of numerous awards and fellowships (APS, AAAS, MRS etc.), and was the inaugural editor in chief of MRS Communications.  He is a former President of the Materials Research Society.

His research is devoted to developing a fundamental understanding of, and controlling, the structure and properties of "soft" materials for applications that include: energy conversion, active and passive coatings, membranes, sensors and organic electronic and electrorheology.


Phase transitions in polyelectrolyte gels
Matt Hennessy, University of Bristol, UK

Abstract:

When a polyelectrolyte gel is placed in an ionic solution, slight alterations in the environmental parameters can trigger enormous changes in the gel volume.  In some cases, the gel volume will change discontinuously, resulting in a volume phase transition.  Many studies of the volume phase transition focus on the equilibrium and electrically neutral states of the gel.  In this talk, I will discuss how a novel phase-field model can be used to explore the evolution of the gel structure during the volume phase transition.  Numerical simulations reveal that the volume phase transition can occur via two routes.  In the first case, a swelling/deswelling front propagates into the gel from its free surface.  In the second case, spinodal decomposition occurs alongside front propagation.  I will then re-visit the assumption of electroneutrality by studying the electric double layer at the gel surface.  Phase separation within the electric double layer can trigger the self-assembly of electrically charged phases throughout the entire gel.  I will conclude by discussing how the breakdown of electroneutrality can provide an alternative interpretation of the volume phase transition.

Bio

Matt completed a DPhil in Applied Mathematics at the University of Oxford in 2014.  Afterwards, he held a postdoctoral fellowship at Imperial College London, a Marie Skłodowska-Curie Fellowship at the Centre de Recerca Matemàtica in Barcelona, and a Hooke Research Fellowship at the University of Oxford.  In 2021, he joined the University of Bristol as a Lecturer in Engineering Mathematics.  His research focuses on the continuum modelling of complex materials.  He is especially interested in instability-driven pattern formation in polymeric systems and its application to functional materials.


Sequence Effects in Calcium-Responsive Biopolymers
Danielle J. Mai, Stanford University, USA

Abstract:

Calcium ions trigger numerous biological phenomena including bone growth, muscle contraction, and neurotransmitter release. Calcium-responsive behavior can be bestowed upon biopolymers by the inclusion of carboxylic acid motifs, such as aspartic acid and glutamic acid residues in proteins. Recently, aspartic acid-rich proteins were shown to fold and unfold in the presence and absence of calcium ions. These proteins comprise tandem repeats of a nine-residue consensus sequence GGXGXDXUX, where G is glycine, D is aspartic acid, X is any amino acid, and U is an aliphatic amino acid. These tandem repeats are called β-roll tags (BRTs) for their ability to form β rolls in the presence of calcium ions. Consensus repeat sequences in BRTs provide a modular platform to systematically determine the influence of amino acid sequence on calcium-responsive biopolymer behavior.

We report a class of calcium-responsive BRT proteins that enable an exploration of the role of amino acid sequence on biopolymer structure and dynamics. A mutation panel of BRT domains adapts a consensus repeat sequence derived from Bordetella pertussis adenylate cyclase to explore the role of charge, hydrophobicity, and sequence heterogeneity on calcium ion-actuated structural changes. Mutations specifically probe the residue in position 5 of the consensus sequence GGXGXDXUX; this residue is hypothesized to influence BRT responsiveness due to its proximity to the calcium-binding aspartic acid in position 6. Calcium-responsive BRTs are integrated into protein-based materials by genetic fusion to crosslinking domains that promote hydrogel formation. We report sequence–property relationships of BRT-containing proteins measured by circular dichroism, shear rheology, and single-molecule force spectroscopy, thereby enabling the multi-scale quantification of calcium-responsive behavior. Overall, biopolymeric materials containing calcium-responsive domains provide a tunable, modular, and naturally derived material platform with promise to mimic the dynamic chemo-mechanical environment of muscle and nerve tissues.

Bio

Danielle J. Mai graduated from the University of Michigan and earned her MS and PhD in Chemical Engineering from the University of Illinois (2016), where she was an Illinois Distinguished Fellow and a National Science Foundation Graduate Research Fellow. She conducted postdoctoral research at MIT, where she won an Arnold O. Beckman Postdoctoral Fellows Award to engineer hydrogels for biosensing and selective bioseparations. She began as an Assistant Professor of Chemical Engineering and James and Anna Marie Spilker Faculty Fellow at Stanford University in 2020. Danielle uses molecular-scale biopolymer engineering to create materials with novel function and structure. The Mai Lab integrates precise biopolymer design with multiscale experimental characterization to advance biomaterials development and to enhance fundamental understanding of soft matter physics.


An industrial perspective of global trends in bio-derived and natural polymers
Andy Sweetman
, Futamura Chemical UK Ltd., UK

Abstract

TBC

Bio

Andy Sweetman is a sustainable packaging market expert, and currently chairs the UK’s Biobased and Biodegradable Industries Association. He is also a past Chairman of the board of European Bioplastics (2009-2013). Following a degree in Modern Languages, and further studies in Packaging Technology, Andy occupied several roles at Innovia, and is currently a director at Futamura UK. He has extensive experience in the flexible packaging industry, with a focus on sustainability and cellulose and bioplastic films.


Rheology and structure formation in soft matter composites
Professor Jan Vermant, ETH Zürich, Switzerland

Abstract

TBC

Bio

Jan studied Chemical Engineering at KU Leuven, Belgium, obtaining his PhD in 1996, and was a postdoctoral fellow of Elf Aquitaine and the Fund for Scientific Research – Vlaanderen. He joined the faculty at KU Leuven in 2000, and ETH Zürich in 2014. He is the recipient of numerous awards, including the Onsager professorship and Onsager medal, and 2019 Weissenberg Award of the European Society of Rheology. His research focuses on the rheology and applications of complex fluid-​fluid interfaces, colloidal suspensions and the development of novel experimental methods and soft matter applications.


Key dates

Abstract submission deadline:

4 July 2022

Early registration deadline:

31 July 2022

Registration deadline:

1 September 2022


Organised by the IOP Polymer Physics Group