Hierarchical transport phenomena in triple-crosslinked biopolymer nanocomposites: a literature-validated computational framework for sustainable active food packaging

This work presents a literature-benchmarked computational framework for predicting synergistic transport, mechanical, and barrier performance in a triple-crosslinked biopolymer nanocomposite engineered for sustainable active food packaging. The hierarchical composite integrates: (i) chemical crosslinking via citric acid thermal esterification (Δ σ chem = 20 MPa); (ii) enzymatic crosslinking via transglutaminase-catalysed ε -( γ -glutamyl)lysine isopeptide bond formation (Δ σ enz = 8 MPa); and (iii) ionic crosslinking via calcium-mediated alginate egg-box coordination (Δ σ ionic = 6 MPa), with hierarchical nanoreinforcement from exfoliated montmorillonite (aspect ratio α p = 100–300). Employing Interpenetrating Polymer Network (IPN) theory within the Sperling framework, with an interference-corrected additive baseline of 13.4 MPa and a mechanistically derived, literature-anchored IPN synergy factor α = 2.42, the framework predicts a tensile strength of 32.4 ± 1.8 MPa – a 6.2-fold increase over a pure starch baseline (5.2 ± 0.8 MPa). Sensitivity analysis confirms that a ±20 % variation in all primary input parameters yields predictions remaining within or close to the experimentally validated literature range. Oxygen barrier performance is predicted at 318 ± 22 cc·mil/m 2 ·day·atm (65 % reduction via tortuous diffusion pathways quantified by Nielsen’s model with explicit treatment of imperfect dispersion). Water vapour transmission rate is predicted at 6.3 ± 0.4 g/m 2 ·day. Aerobic biodegradation is predicted at 89.2 ± 2.1 % mass loss within 120 days per ASTM D5338. A pH-triggered chitosan nanoparticle antimicrobial release system delivers ≥2 log reduction in Staphylococcus aureus and Escherichia coli upon pH decrease to 5.5–6.5, extending produce shelf-life by 14–28 days. All predictions are anchored to 11 independent peer-reviewed experimental sources and benchmarked against mechanistic, dimensional, literature-range, and thermodynamic consistency pathways. The framework is explicitly interpolative within the benchmarked parameter space and does not claim to replace experimental verification; complete experimental protocols enabling independent laboratory confirmation are disclosed in Section 5.