Prof. A. Dinsmore, UMass Amherst Physics Department

(Last taught in Fall05)

Here is a summary of the lecture topics with links to scanned lecture notes in pdf format. The notes are currently password-protected, but there is a clue to the password on the longin page. I am also happy to send the password on request (e.g. by email).

News: 9/7/07-Notes for Ch 9 and 10 were uploaded.

- Introduction. (Notes: 14 pages, 1.4 MB)
- Examples of soft materials in industry and biology.
- Foams as a lead-off example of macro properties derived from micro.
- Atomic- and molecular-scale forces and bonds.
- Repulsion, entropy, hydrophobicity.

- van der Waals Forces. (Notes: 23 pages, 3.4 MB)
- Keesom, Debye, and London contributions.
- Mean-field models of media.
- Measurements; list of Hamaker constants, relationship to surface tension.
- Derjaguin approximation; interaction between spherical particles (not 1/r^6)

- Review of Statistical Mechanics. (Notes; 12 pages, 1.3 MB)
- Probabilities; Boltzmann distribution, Helmholtz energy, Equipartition theorem.
- Example of pulling RNA and measuring stiffness of a network (experiments).

- Fluctuation-induced forces. (Notes; 11 pages. 2.7 MB)
- Osmotic pressure
- Depletion attraction
- Repulsion between membranes
- Tension in a polymer

- Polymers (1 dimensional materials existing in 3D). (Notes (Part A); 14 pages, 2.3 MB)
- Part A: Survey of types of polymers.
- ...Ideal-chain and Freely-jointed chain models.
- Part B:Worm-like chain (Kratky-Porod) model. (Notes (Part B); 10 pages, 1.6 MB)
- ...The spectrum of fluctuations and the stiffness of a single polymer.

- Friction in Fluids: the Langevin Equation of motion of a particle
in fluid. (Notes; 10
pages, 1.8 MB)
- Viscosity and a simple model for its value; terminal velocity; sedimentation.
- The mean-square displacement, Fluctuation-dissipation theorem.

- The Diffusion Equation. (Notes 21 pages, 3.4 MB)
- A free particle; an ink spot; diffusion to capture, etc.
- Particle-hopping model; Fick's law; diffusion with drift.
- Experimental methods: Dynamic light scattering and the correlation function.
- An aside: Measuring interactions: terminal velocity; g(r); Boltzmann method.

- Fluid Interfaces (2 dimensional materials existing in 3D). (Notes;
31 pages, 2.7 MB)
- Surface tension, surfactants and Pickering emulsions.
- Consequences of a surface tension: LaPlace pressure, Jurin's Law, the Rayleigh instability, the Young-Dupre law and wetting, the shape of a meniscus: the equation of capillarity. Forces among interfacial inclusions (the 'Cheerios Effect').
- Assembly of particles at liquid interfaces

- Lipid Bilayer Membranes. (Notes;
17 pages, 1.4 MB)
- Overview of vesicles and cell membranes.
- The Helfrich model and bending modulus
- The spectrum of thermal fluctuations; roughness of a membrane at finite temperature.
- Vesicles.

- Electrostatics in Solution (3D).
(Notes; 25
pages, 3.6 MB)
- Poisson-Boltzmann theory and Debye length
- Inter-particle forces, pH.

- Structure in 3D.
- Packing spheres in 3D: Close-packing geometry; minimum contact #.
- Long- and short-range order and frustration.
- Liquid crystalline meso-phases.

- Phase separation.
- Phenomenological models for hard spheres,
- Flory Huggins theory for polymers.
- Binodals and spinodals.

- Random aggregation and fractals.
- DLA and DLCA.
- (Unfortunately, I have not found time for phase transitions in 2D: KTHNY theory and disclinations)

- Fluid Dynamics. (Notes; 20
pages, 1.1 MB)
- The Navier-Stokes equation for an isotropic fluid.
- Reynolds Number, Re.
- laminar flow, Poiseuille flow, lubrication.

- Continuum Elasticity and Viscoelasticity. (Notes on elasticity; 24
pages, 1.2 MB; Notes on microrheology; 7
pages, 0.36 MB))
- Elasticity: stress, strain and the modulus.
- Thermal displacements in 1D, 2D and 3D lattices (for polymers, membranes and 3D solids)
- The loss modulus; viscoelasticity; frequency dependence of the modulus
- Microrheology: G*(?) from the mean-square displacement.

Here is deGenne's description of soft matter (from a Nobel lecture, reprinted in Rev. Modern Phys.).