Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Interfacial Phenomena: Size Effects and Phase Transitions

In course

MSE-304: Surfaces and interfaces

This lecture introduces the fundamental concepts for describing, characterizing, and engineering surfaces and interfaces. Students will develop both theoretical and practical understanding of how interfacial phenomena influence surface properties and techn ...

Description

This lecture delves into the significance of interfacial phenomena in material science, focusing on how finite size affects phase transitions. The instructor explains how materials of different sizes exhibit altered transition temperatures, using examples like ice nanoparticles melting at lower temperatures. The concept of nucleation and growth is explored, emphasizing the formation of nuclei to initiate phase changes. Additionally, the lecture covers Ostwald ripening, where smaller crystals are absorbed by larger ones, leading to crystal size convergence. Throughout the class, the instructor highlights the role of surface energy in determining chemical potential and phase equilibrium, showcasing how these principles manifest in various material science applications.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructors (2)

Nako Nakatsuka

Francesco Stellacci

Francesco Stellacci graduated in Materials Engineering at the Politecnico di Milano in 1998 with a thesis on photochromic polymers with Prof. Giuseppe Zerbi and Mariacarla Gallazzi. In 1999 he moved to the Chemistry Department of the University of Arizona for as a post-doc in the group of Joe Perry in close collaboration with the group of Seth Marder. In 2002 he moved to the Department of Materials Science and Engineering at the Massachusetts Institute of Technology as an assistant professor. He was then promoted to associate without (2006) and with tenure (2009). In 2010 he moved to the Institute of Materials at EPFL as a full Professor. He holds the Alcan EP Chair. Francesco was one of the recipients of the Technology Review TR35 "35 Innovator under 35" award in 2005, and the Popular Science Magazine "Brilliant 10" award in 2007. He has been a Packard Fellow starting 2005.

Official source

Related concepts (11)

Surface science

Surface science is the study of physical and chemical phenomena that occur at the interface of two phases, including solid–liquid interfaces, solid–gas interfaces, solid–vacuum interfaces, and liquid–gas interfaces. It includes the fields of surface chemistry and surface physics. Some related practical applications are classed as surface engineering. The science encompasses concepts such as heterogeneous catalysis, semiconductor device fabrication, fuel cells, self-assembled monolayers, and adhesives.

Surface energy

In surface science, surface free energy (also interfacial free energy or surface energy) quantifies the disruption of intermolecular bonds that occurs when a surface is created. In solid-state physics, surfaces must be intrinsically less energetically favorable than the bulk of the material (the atoms on the surface have more energy compared with the atoms in the bulk), otherwise there would be a driving force for surfaces to be created, removing the bulk of the material (see sublimation).

Phase transition

In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma. A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change as a result of the change of external conditions, such as temperature or pressure.

Surface tension

Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged. At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion). There are two primary mechanisms in play.

Phase (matter)

In the physical sciences, a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable. In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air is a third phase over the ice and water. The glass of the jar is another separate phase. (See .) More precisely, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform.

Related lectures (36)

Binary Systems: Eutectic and Peritectic Transformations

Explores eutectic and peritectic transformations in binary systems, phase diagrams, and surface energy in materials science.

Thin Films: Deposition and Growth

Explores thin film preparation, growth mechanisms, organic film considerations, and deposition techniques in electronics.

Polymer Phase Behavior

Explores the physical chemistry of polymeric materials, emphasizing concentrated solutions and phase separation behavior.

Interfacial Chemistry: Surface Tension, Adsorption, Electrokinetics

Covers surface tension, adsorption, and electrokinetics, including gas/liquid interface, Langmuir isotherm, and electro-osmosis.

The Crystalline Phase: Polymers and Crystallization