Soft matter is a subfield of condensed matter comprising a variety of physical states that are easily deformed by thermal stresses or thermal fluctuations. They include liquids, colloids, polymers, foams, gels, granular materials, and a number of biological materials. These materials share an important common feature in that predominant physical behaviors occur at an energy scale comparable with room temperature thermal energy. At these temperatures, quantum aspects are generally unimportant. Pierre-Gilles de Gennes, who has been called the "founding father of soft matter," received the Nobel Prize in physics in 1991 for discovering that the order parameter from simple thermodynamic systems can be applied to the more complex cases found in soft matter, in particular, to the behaviors of liquid crystals and polymers.
Interesting behaviors arise from soft matter in ways that cannot be predicted, or are difficult to predict, directly from its atomic or molecular constituents. This is often because soft matter self-organizes into mesoscopic physical structures that are much larger than the microscopic scale (the arrangement of atoms and molecules), and yet are much smaller than the macroscopic (overall) scale of the material. The properties and interactions of these mesoscopic structures may determine the macroscopic behavior of the material. For example, the turbulent vortices that naturally occur within a flowing liquid are much smaller than the overall quantity of liquid and yet much larger than its individual molecules, and the emergence of these vortices control the overall flowing behavior of the material. Also, the bubbles that comprise a foam are mesoscopic because they individually consist of a vast number of molecules, and yet the foam itself consists of a great number of these bubbles, and the overall mechanical stiffness of the foam emerges from the combined interactions of the bubbles. By way of contrast, in hard condensed matter physics it is often possible to predict the overall behavior of a material because the molecules are organized into a crystalline lattice with no changes in the pattern at any mesoscopic scale.
Soft materials are important in a wide range of technological applications. They may appear as structural and packaging materials, foams and adhesives, detergents and cosmetics, paints, food additives, lubricants and fuel additives, rubber in tires, etc. In addition, a number of biological materials (blood, muscle, milk, yogurt, jello) are classifiable as soft matter. Liquid crystals, another category of soft matter, exhibit a responsivity to electric fields that make them very important as materials in display devices (LCDs). In spite of the various forms of these materials, many of their properties have common physicochemical origins, such as a large number of internal degrees of freedom, weak interactions between structural elements, and a delicate balance between entropic and enthalpic contributions to the free energy. These properties lead to large thermal fluctuations, a wide variety of forms, sensitivity of equilibrium structures to external conditions, macroscopic softness, and metastable states.
The realization that soft matter contains innumerable examples of symmetry breaking, generalized elasticity, and many fluctuating degrees of freedom has re-invigorated classical fields of physics such as fluids (now generalized to non-Newtonian and structured media) and elasticity (membranes, filaments, and anisotropic networks are all important and have common aspects). Soft condensed matter is directly related to studies in biophysics. One possible roadblock to the development of biophysics as an established field is that soft condensed matter may be diverging into two distinct directions: a physical chemistry approach and a complex systems approach.
Multi-Investigator Groups and Centers
- Physical and Colloid Chemistry, Utrecht University
- Soft Condensed Matter group, Utrecht University
- Oxford Centre for Soft and Biological Matter
- AMOLF Institute, Amsterdam, Netherlands
- New England Complex Fluids Workgroup
- the Brandeis Complex Fluids Group
- the Chicago Soft Matter Collective
- Dynamics of Complex Fluids department at the Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Soft Matter Group at van der Waals-Zeeman Institute, University of Amsterdam, NL
- Soft Matter Chemistry Group, University of Leiden, NL
- Freiburg Institute for Advanced Studies (FRIAS), School of Soft Matter Research, University of Freiburg, D
- Center for Soft Matter Research New York University, US
- Physics of Soft and Partially Ordered Matter Faculty of Mathematics and Physics University of Ljubljana, SLO
- Soft Matter and Molecular Biophysics Group, Department of Applied Physics, University of Santiago de Compostela, Spain
- Soft Matter Team, Laboratoire Charles Coulomb, CNRS and University Montpellier 2, Montpellier, France
- Matière et Systèmes Complexes, CNRS, Université Paris Diderot, France
- Laboratoire de Physique des Solides, CNRS, Université Paris 11, Orsay, France
- Gulliver, d'une échelle à une autre, CNRS, ESPCI, Paris, France
- Matière molle et chimie, CNRS, ESPCI, Paris, France
- Physique et Mécanique des Milieux Hétérogènes, CNRS, ESPCI, Paris, France
- Physico-chimie des Polymères et Milieux Dispersés Sciences et Ingénierie de la Matière Molle, ESPCI Paris, France
- Laboratoire Colloïdes et Matériaux Divisés, CNRS, ESPCI, Paris
- Group of Microfluidics, Chemical Organisation and Nanotechnology, ENS Paris, France
- Physicochimie Curie, Institut Curie Paris, France
- Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire, CEA Saclay
- Service de Physique de l'État Condensé, CEA Saclay
- Institut de Physique de Rennes, équipe matière molle, CNRS, Université de Rennes 1, France
- Institut Charles Sadron, CNRS, Université de Strasbourg, France
- Centre de Recherche Paul Pascal, Bordeaux, Paris, France
- Laboratoire du Futur, CNRS, Rhodia, Bordeaux, France
- LPMCN, équipe Liquides aux interfaces, CNRS, Université de Lyon 1, France
- Polymer and Soft Matter Team, Department of Physics, Université Libre de Bruxelles, Brussels, Belgium
- Interface and complex fluids laboratory, Université de Mons, Belgium
- Laboratoire de Physique, CNRS, ENS Lyon, Lyon, France
- Groups of Prof. Fuchs and Maret, University of Konstanz, Germany
- Groups of Prof. Hinrichs and Weiss, University of Hohenheim, Stuttgart, Germany
- Soft Condensed Matter Physics Group, Centre for Molecular and Nanoscale Physics, RMIT University, Melbourne, Australia
- The Institute for Soft Matter Synthesis and Metrology at Georgetown University
- Soft Matter Physics Group (Weitzlab), Harvard University, US
- Soft Matter Physics Group at University of Leipzig (Käslab), Germany
- Nagel Group, University of Chicago, US
- Prof. Peter Schurtenberger's Group, Adolphe Merkle Institute, CH
- Yang Zhang's Group, University of Illinois at Urbana-Champaign, US
- Dr. Martin O. Steinhauser's Research Group 'Shock Waves in Soft Biological Matter' at the Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI, Freiburg, Germany
- Prof A V Zvelindovsky's Computational Physics Group, University of Central Lancashire, UK
- Dr. Ramón Castañeda-Priego's Group, Mexico
- Rolando Castillo's Group at UNAM, Mexico
- Theory and Computation of Advanced Materials, Stephan Baeurle's Group at Regensburg University, Germany
- David Grier's Group, New York University, US
- Eric Weeks' Group, Emory University, US
- Computational Soft Matter Science, Prof. Florian Müller-Plathe's Research Group
- Polymer Physics and Complex Fluids Group, Yeng-Long Chen's Research Group at Academia Sinica
- Soft Matter Lab, Memorial University of Newfoundland, Canada
- Polymer and Condensed Matter Physics Group, Greg McKenna's Labs, Texas Tech University, US
- Prof. Linda Hirst's soft matter physics group, University of California, Merced, US
- Losert Lab, University of Maryland, US
- Simone Napolitano's Polymer and Soft Matter Dynamics Lab, Université Libre de Bruxelles, Brussels, Belgium
- Damien Baigl Laboratory, ENS Paris, France
- Byung Mook Weon's Soft Matter Physics Lab, Sungkyunkwan University, South Korea
- Giovanni Volpe's Soft Matter Lab at Bilkent University, Ankara, Turkey
- Sam Safran's group: Theory of soft and biological matter, Weizmann Institute of Science, Israel
- Nature Physics
- Physical Review Letters
- Physical Review E
- Soft Matter
- Journal of Physics: Condensed Matter
- Journal of Chemical Physics
- Journal of Physical Chemistry Letters
- Journal of Physical Chemistry B
- Journal of Physical Chemistry C
- European Physical Journal E
- Nano Letters
Examples of soft matter
- Complex fluids
- Liquid crystals
- Foams, gels, microemulsions
- Proteins, membranes and other biomaterials
- Granular materials
- I. Hamley, Introduction to Soft Matter (2nd edition), J. Wiley, Chichester (2000).
- R. A. L. Jones, Soft Condensed Matter, Oxford University Press, Oxford (2002).
- T. A. Witten (with P. A. Pincus), Structured Fluids: Polymers, Colloids, Surfactants, Oxford (2004).
- M. Kleman and O. D. Lavrentovich, Soft Matter Physics: An Introduction, Springer (2003).
- M. Mitov, Sensitive Matter: Foams, Gels, Liquid Crystals and Other Miracles, Harvard University Press (2012).
- J. N. Israelachvili, Intermolecular and Surface Forces, Academic Press (2010).
- A. V. Zvelindovksy (editor), Nanostructured Soft Matter - Experiment, Theory, Simulation and Perspectives, Springer/Dodrecht (2007), ISBN 978-1-4020-6329-9.
- M. Daoud, C.E. Williams (editors), Soft Matter Physics, Springer Verlag, Berlin (1999).
- Gerald H. Ristow, Pattern Formation in Granular Materials, Springer Tracts in Modern Physics, v. 161. Springer, Berlin (2000). ISBN 3-540-66701-6.
- de Gennes, Pierre-Gilles, Soft Matter, Nobel Lecture, December 9, 1991.
- S. A. Safran,Statistical thermodynamics of surfaces, interfaces and membranes, Westview Press (2003)
- Rheology Bulletin Volume 74 Number 2 July 2005, p. 17
- ""The Nobel Prize in Physics 1991"". Retrieved January 27, 2008.
- Pierre-Gilles de Gennes' Nobel Lecture
- SklogWiki - a wiki dedicated to simple liquids, complex fluids, and soft condensed matter.
- Harvard School of Engineering and Applied Sciences Soft Matter Wiki - organizes, reviews, and summarizes academic papers on soft matter.
- Google Scholar page on soft matter