Struct HydrogelModel 

pub struct HydrogelModel {
    pub chi: f64,
    pub n_chains: f64,
    pub nu_0: f64,
    pub molar_volume_solvent: f64,
    pub shear_modulus: f64,
}

Flory-Rehner equilibrium swelling model for hydrogels.

Balances elastic (network) and mixing (polymer-solvent) free energies to find the equilibrium swelling ratio Q.

Fields

chi: f64

Flory-Huggins interaction parameter χ (dimensionless).

n_chains: f64

Number of chain segments between cross-links N (Kuhn monomers).

nu_0: f64

Reference polymer volume fraction ν_0 (dry state, typically 1.0).

molar_volume_solvent: f64

Molar volume of solvent [m³/mol].

shear_modulus: f64

Shear modulus of dry network G_0 [Pa].

Implementations

impl HydrogelModel

pub fn new(chi: f64, n_chains: f64, shear_modulus: f64) -> Self

Construct a HydrogelModel with standard parameters.

pub fn mixing_chemical_potential(&self, phi: f64) -> f64

Mixing free energy (Flory-Huggins) chemical potential term [dimensionless].

Δμ_mix / (RT) = ln(1-φ) + φ + χ*φ² where φ = polymer volume fraction.

pub fn elastic_chemical_potential(&self, phi: f64) -> f64

Elastic free energy chemical potential term [dimensionless].

Δμ_el / (RT) = (Vs/Vref) * N^(-1) * (φ/2 - φ^(1/3))

pub fn total_chemical_potential(&self, phi: f64) -> f64

Total chemical potential (mixing + elastic) for equilibrium condition.

pub fn equilibrium_swelling_ratio(&self) -> f64

Find equilibrium swelling ratio Q = V_swollen / V_dry numerically.

Solves μ_total(φ) = 0 by bisection over φ ∈ [1e-4, 1-1e-4]. Returns volumetric swelling ratio Q = 1/φ_eq.

Trait Implementations

impl Clone for HydrogelModel

fn clone(&self) -> HydrogelModel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for HydrogelModel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.