Fundamentals of phase transitions (Laurence Talini)
The objective of this course is to review (and refresh!) the fundamentals of thermodynamics of state changes. We will begin with the thermodynamic description of phase changes and detail the principles governing phase diagrams of pure substances and mixtures. The cases of liquid-solid and liquid-vapor transitions will be examined in greater detail. We will also discuss the metastable states that can form, as well as the special case of the glass transition.
Bio: Laurence Talini is a physicist specializing in soft matter. After holding a position at Sorbonne Université, she joined the French National Centre for Scientific Research (CNRS) as a senior researcher in 2019. Her recent work explores transfer phenomena and interfacial flows in situations where they are driven by small-scale physico-chemical properties. She conducts her research at the Surface du Verre et Interfaces (SVI) laboratory, a joint unit between CNRS and Saint-Gobain, where the scientific questions she addresses are often linked to industrial issues.
The growth and morphology of icicles (Stephen Morris)
The shape of an icicle emerges from a complex interplay of fluid dynamics, heat transfer and phase change. Ideal icicles are predicted to have a universal "platonic" shape, independent of growing conditions. In addition, some icicles exhibit a rippled shape, which appears to be the result of a somewhat mysterious morphological instability. The wavelength of the ripples is also remarkably independent of the growing conditions. Similar shape and ripple phenomena are also observed on stalactites, although many details of their formation differ. We built a laboratory icicle growing machine to explore icicle physics. We learned what it takes to make a platonic icicle and of the surprising dependence of the rippling instability on water purity. Impurities are also found to be distributed in a complex pattern within the ice. The wetting of the ice surface also depends strongly on water purity. We review the rather sorry state of theories of the ripples. We conclude with a review of what is and what is not known about icicle growth.
Papers: https://www.physics.utoronto.ca/nonlinear/papers_icicles.html
The Icicle Atlas: https://www.physics.utoronto.ca/Icicle_Atlas/https://www.physics.utoronto.ca/Icicle_Atlas/
Bio: Stephen W. Morris is Professor emeritus of physics at the University of Toronto. His research involves experiments on emergent patterns in fluids, granular media, ice formations and fracture. He is also interested in natural patterns, and in the history of physics. He is a Fellow of the American Physical Society and a former holder of the University of Toronto J. Tuzo Wilson chair of geophysics. He has sometimes exhibited his scientific images as art.
How freezing deforms soft materials (Rob Style)
We all know that freezing can cause stresses that significantly deform or even damage soft, wet materials. This arises in examples including pothole formation caused by freezing/melting wet soils, or when food changes texture after it has been frozen. However, interestingly, the source of these stresses is not what most people might expect: the fact that water expands by about 10% as it freezes. This explanation is easily proven to be wrong by simply freezing soft materials immersed in liquids that shrink as they freeze (e.g. benzene) – this leads to similar deformation and damage. Instead, the key mechanism for stress generation is a process known as cryosuction, whereby water is sucked through a wet material towards growing ice. This transport of liquid leads to highly localised ice growth, which pushes open pores in the freezing material, ultimately causing damage.
We will lay out the physics that describes the cryosuction process, and explain how this leads to deformation and damage. There will be a particular focus on applications ranging from frost heave to cryopreservation.
Bio: Originally from England, Rob Style got his PhD studying the physics of ice growth at Cambridge University in the UK. He then had postdoctoral positions at Oxford (UK) and Yale (USA) working on freezing and the mechanical properties of soft solids, before taking a post as a Departmental lecturer at Oxford, and subsequently moving to be a Group Leader in the Department of Materials at ETH. His research interests include freezing, phase separation, capillary phenomena, membrane physics, solid and fluid mechanics, and fracture.
The surface of ice (Luis MacDowell)
The interaction of ice with our environment is very often dictated by its surface properties. In this series of lectures, a number of theoretical tools in statistical mechanics will be used to describe the microscopic structure of the ice surface, including surface thermodynamics, wetting physics, intermolecular forces, capillary waves and crystal growth theory. Combining the theoretical methods with complementary insight gained from experiments and computer simulations, a consistent picture of ice premelting will emerge which serves to explain a wide range of physical phenomena ranging from the growth of snow crystals to ice friction.
The course will be divided in four parts:
1. Surface thermodynamics and wetting physics
2. Surface structure and crystal growth dynamics
3. Ice friction.
Bio: Luis G. MacDowell was educated in the Universidad Complutense de Madrid, performing stays at the Université Libre de Bruxelles and the Johanes Gutenberg Uniiversität. After receiving his PhD in 2000, he was a postdoctoral researcher at Mainz and a Ramón y Cajal fellow in Madrid, where he is currently full professor at the Chemical Physics department. He has been visiting fellow at the Marie Curie-Sklodowska university of Lublin and at the Department of Applied Mathematics at the University of Loughborough. His research interests focus on the statistical mechanics and computer simulation of interfacial phenomena, including wetting physics, capillarity, nucleation, and crystal growth.
Analogue systems of speleothem formation (Anne Mongruel)
Cave deposits (speleothems) result from flow and precipitation of salt aqueous solutions, mainly calcium carbonate. Their various shapes, spanning from mineral straws, stalactites and stalagmites, to draperies and flowstones, are remarkably similar to those of their icy counterparts: e.g. icicles and frozen cascades. In all cases, the coupling between a flow and a solidification process produces generic growth mechanisms, leaving specific chemical reactions or phase changes on a secondary, more quantitative, plan.
In this lecture, I will discuss the similarities between these two (mineral and icy) systems. I will review their analogies and contrasts in the incremental formation of a solid structure by mineral precipitation from a solution, or by solidification from a melt, highlighting the role of the fluid dynamics. Examples will be taken from the literature and from our recent lab experiments at PMMH.
Bio: Anne Mongruel is assistant professor at Sorbonne Université and researcher at Physique et Mécanique des Milieux Hétérogènes. Her main research topics are the hydrodynamics of particulate systems, with applications to near-wall hydrodynamics, and the phase change at interfaces with applications to water condensation and dew recovery. She has started recently an experimental project on the growth of speleothems in the lab.
Physics of the permafrost (Daniel Fortier)
The objective of this course is to discover the world of permafrost. Basic concepts of permafrost science, permafrost types and permafrost distribution will be reviewed. We will then study selected significant permafrost landforms and the geomorphological, geotechnical and geothermal processes leading to landforms development. We will review the principles of cryostratigraphy and the different types of permafrost ground ice along with associated heat and mass transfers. Finally, we will evaluate the processes of permafrost degradation (e.g. thermokarst and thermal erosion) and the resulting landforms and landscapes.
Bio: Daniel Fortier is a professor of geomorphology at the Université de Montréal and a leading expert on Arctic permafrost. His research focuses on cryostratigraphy, permafrost dynamics, and ground-ice processes, with fieldwork spanning Nunavut, Yukon, Nunavik.. As director of the Geocryolab, he integrates geomorphology, geotechnical engineering, and climate science to understand how northern landscapes respond to environmental change. Fortier has led and contributed to major national and international research programs. He is also an active editor, mentor, and contributor to scientific networks on permafrost and cold-regions processes.
