Flory-Huggins Polymer Blends
Free energy of mixing, spinodal, binodal, phase diagram
ΔF/nkT = φ·ln(φ)/N₁ + (1−φ)·ln(1−φ)/N₂ + χ·φ·(1−φ)
Spinodal: ∂²F/∂φ² = 0 | Binodal: equal chemical potentials | χ_c = ½(1/√N₁ + 1/√N₂)²
Flory-Huggins χ parameter =
0.5
Chain length N₁ (polymer A) =
100
Chain length N₂ (polymer B) =
100
Composition φ =
0.5
—
ΔF/nkT
—
χ_critical
—
φ_critical
—
Phase state