Interfacial association, hydration and polarization in PLA/PCL/PEG/nanozeolite membranes: a DFT framework

Background: Interfaces between polylactic acid (PLA), polycaprolactone (PCL), poly (ethylene glycol) (PEG) and nanozeolite in composite membranes couple interfacial stability with competition for water-binding sites, yet no consistent electronic-structure framework separates polymer association, hydration and polarization effects.
Objectives: This study aims to propose a density functional theory (DFT) protocol that links polymer association, water-site accessibility and electronic polarization within one energetic reference.
Method: A protocol-development design was applied. Counterpoise-corrected many-body decomposition, electrostatic and density-topology descriptors, frontier response, hydration thermochemistry, vibrational shifts and finite-field polarization were defined, and their workflow was demonstrated with an internally consistent numerical illustration built from author-assigned values (not computed) using Python/NumPy arithmetic. r²SCAN-3c geometries and PBE0-D4/def2-TZVPD single points are specified for subsequent validation.
Findings and Implications: Within the assigned illustration, the four-component binding energy of ?2.340 eV arises mainly from pair contacts and PEG–zeolite coupling (?0.818 eV), whereas the strict four-body term is weak (?0.032 eV). Water association reaches ?0.812 eV, but a positive three-body hydration term (+0.097 eV) represents competition for cationic sites, and fields of ±2×10?? a.u. produce modest directional energy changes of approximately 5.5 meV. These values are illustrative hypotheses rather than computed findings.
Conclusion: The framework yields a testable design criterion, namely preserving accessible oxygen sites while limiting deformation and competition for cationic sites, and defines the DFT calculations required before application to specific membrane compositions.