Introductory physics going soft

Abstract

We describe an elective course on soft matter at the level of introductory physics. Soft matter physics serves as a context that motivates the presentation of basic ideas in statistical thermodynamics and their applications. It also is an example of a contemporary field that is interdisciplinary and touches on chemistry, biology, and physics. We outline a curriculum that uses the lattice gas model as a quantitative and visual tool, initially to introduce entropy, and later to facilitate the calculation of interactions. We demonstrate how free energy minimization can be used to teach students to understand the properties of soft matter systems such as the phases of fluid mixtures, wetting of interfaces, self-assembly of surfactants, and polymers. We discuss several suggested activities in the form of inquiry projects which allow students to apply the concepts they have learned to experimental systems.

Evolution in students’ understanding of thermal physics with increasing complexity

“…The performance of students in stage D is not part of this study. A more detailed discussion of the curriculum, including the mathematical adjustments and supporting teaching activities that were used, can be found in a separate paper [5].…”

“…These revisions allowed us to refine the presentation of the underlying concepts and principles into a coherent, continuous curriculum for which a more comprehensive description can be found in a separate paper [5].…”

“…The last five meetings of this stage (meetings 14-18) present the free energy analysis of surface-related phenomena and surfactant self-assembly. The full derivation of the phase separation analysis as well as the analyses of other soft matter phenomena was discussed in detail in a separate paper [5].…”

“…The utility of the free energy in allowing one to focus on the internal energy and entropy of the system, where the heat bath serves only to fix the temperature in equilibrium, is examined. Stage C spans eight meetings and focuses on a modeling sequence [5] that involves the application of free energy minimization to systems of interacting particles. The free energy of attracting particles that show transitions from mixed to phase separated states is analyzed quantitatively in terms of the internal energy and entropy using a mean-field approximation.…”

“…To substantially broaden the scope of the traditional thermal physics unit in introductory courses, we proposed a novel interdisciplinary curriculum on soft matter [5]. The curriculum was introduced in a program for interested Israeli high school students majoring in chemistry and/or physics [6].…”