Soft Matter-S3

Soft Matter

Contact: Kheya Sengupta

Principles of Soft Condensed Matter Physics

Abstract: This course intends to treat “Soft Matter” as a subfield of Condensed Matter physics, underlining the unifying principles. Soft Matter is defined as matter in which the interactions between the constituent particles, which may be molecules, macromolecules or larger entities, is weak and as a consequence, one defining property of soft matter is the ease with which small external forces can deform them. This means that they not only distort and flow easily, but also that thermal fluctuations play an important, often dominant, role in defining their properties. The structural diversity of soft materials means that they encompass a multitude of symmetry groups, some of which are not found elsewhere, and often exhibit interesting defect dominated phases. The prevalence of entropy dominated states and transitions, the relevance to every-day materials ranging from coffee and whipped cream to soap and paint, and the connection to active and living matter makes soft matter endlessly fascinating.

Content :

  1. Revisit concepts of free energy, entropy and temperature; Introduction to forces, energies and length/time-scales in soft matter; Notions of entropic forces, thermal fluctuations; Examples of Soft Matter: Liquid Crystals (Nematic and Smectic phases), Colloids, Polymers, Surfactants, Membranes.
  2. Revisit phase space and ensembles (classical stat mech); correlations and ordered systems; Introduction to order parameter.
  3. Symmetry and scattering; Disordered and ordered phases (examples from Liquid Crystals and ordered phases of surfactants and polymers)
  4. Elasticity and deformation in anisotropic media (focus on Liquid Crystalline phases)
  5. Defects and defect phases (with examples from Soft Matter)
  6. Phase transitions and notion of Landau Theory (with examples from Soft Matter)
  7. Fluctuations and dissipation
  8. Rheology of complex fluids (focus on polymers)
  9. Basics of hydrodynamics, life at low Reynold’s numbers
  10. Forces and potentials at surfaces and interfaces (focus on colloids and membranes)
  11. From soft to living systems
  12. New developments in active matter


Pre-requisite: Classical statistical mechanics, elements of thermodynamics, familiarity with basic mathematics.