Physics of mesoscopic condensed matter where thermal energy k_BT competes with elastic and interaction energies: colloids, polymers, liquid crystals, granular media, active matter. The regime where statistical mechanics, continuum…
soft-matter
Colloid physics
Dispersions of mesoscopic particles (1 nm–1 μm) in a fluid, where Brownian motion keeps them suspended and pairwise DLVO (van der Waals +…
Liquid crystal
Phases with orientational order but partial or no positional order: nematic (directional only), smectic (layered), cholesteric (helical).…
Polymer physics
Long chains treated as random walks in dilute solution (ideal R ~ N^{1/2}, self-avoiding R ~ N^{3/5} Flory). Gaussian chains give rubber…
Granular physics
Assemblies of macroscopic athermal particles (sand, grains, powders) that are dissipative and out of thermal equilibrium. Exhibit jamming…
Jamming transition
Sharp rigidity transition at packing fraction φ_J ≈ 0.64 (random close packing) for frictionless spheres: below, system is fluid-like;…
Brownian motion (mesoscale)
Stochastic motion of suspended particles driven by solvent kicks. Langevin equation m ẍ = -γẋ + ξ(t) with ⟨ξ(t)ξ(t')⟩ = 2γk_BTδ(t–t')…
Active matter
Systems of self-propelled agents consuming energy locally (bacteria, motor proteins, birds, self-phoretic colloids). Break detailed…
Rheology of complex fluids
Stress–strain response of non-Newtonian fluids: shear-thinning/thickening, viscoelasticity (Maxwell model η(ω) = G∞τ/(1+iωτ)), yield stress…
Self-assembly
Spontaneous organisation of building blocks into ordered structures driven by weak, reversible interactions (hydrogen bonds, depletion, DNA…
Critical Casimir forces
Long-range effective interactions between surfaces immersed in a near-critical binary solvent, caused by confined thermal fluctuations.…
Ericksen–Leslie equations for nematic liquid crystals (soft-matter)
Soft-matter application of L0 partial-differential-equation theory and variation-of-parameters. Liquid-crystal nematics are described by a…
Cahn–Hilliard spinodal decomposition and instability threshold (soft-matter)
Soft-matter application of L0 reaction-diffusion equation theory and initial-value-problem theory. The Cahn–Hilliard equation ∂_t φ =…
DLVO (1940s)
Derjaguin-Landau-Verwey-Overbeek 1940s colloidal-stability: van-der-Waals + electrostatic; modern extended-DLVO non-DLVO forces.
Liquid crystals (de Gennes 1971)
P G de Gennes 1971 'Physics of Liquid Crystals'; modern LCD-displays + Frank-elastic-constants; OLED-display alternative.
Flory-Huggins (polymer)
Flory-Huggins 1942 chi parameter; modern self-consistent-field-theory Matsen 1996 block-copolymer phase-diagrams.
Granular (Jaeger-Nagel 1992)
Jaeger-Nagel 1992 'Physics of the Granular State' Science review; foundational granular-matter physics; modern jamming Liu-Nagel 1998.
Active matter
Marchetti 2013 hydrodynamics-of-active-matter review; modern bacterial + actomyosin + driven-colloid experiments + theory.
Foams (Weaire-Hutzler 1999)
Weaire-Hutzler 1999 'Physics of Foams'; modern Princen-Kiss + soap-froth coarsening + Plateau-rules.
Rouse-Zimm dynamics
P Rouse 1953 + Zimm 1956 polymer-dynamics; modern reptation-de-Gennes 1971 + DPD simulation methods.
Flory-Huggins (1942)
P Flory + M Huggins 1942 polymer-solution-thermodynamics ΔG_mix=kT[φ_1lnφ_1+φ_2lnφ_2/N+χφ_1φ_2]; modern phase-diagrams.
DLVO (Derjaguin-Verwey 1941)
B Derjaguin 1941 + Verwey-Overbeek 1948 DLVO colloid-stability; modern extended-DLVO non-DLVO solvation contributions.
Bagnold scaling (1954)
R Bagnold 1954 grain-flow regimes; modern μ(I) rheology Pouliquen + creep-failure earthquake-analogy avalanches.
Active matter (Marchetti 2013)
Marchetti 2013 hydrodynamics-of-soft-active-matter review; modern living-matter + bacterial + cytoskeletal MIPS.
Jamming (Liu-Nagel 1998)
A Liu-S Nagel 1998 jamming-phase-diagram; modern protein-condensate + cytoplasm + emulsion glass-transition.