Lagrangian Formulation of Interfacial Energetics and Higher-Order Electric-Field Response in PLA/PCL/PEG–Nanozeolite Membranes
Downloads
Quantum-mechanical descriptions of electrically assisted membrane fabrication require a consistent relationship among the applied electric field, interfacial structure, and electronic energy. This study developed a Lagrangian and variational framework for density functional theory (DFT) modeling of poly(lactic acid)/polycaprolactone/poly(ethylene glycol) (PLA/PCL/PEG)–nanozeolite interfaces relevant to electric-field-assisted nonsolvent-induced phase separation (E-NIPS) under an applied voltage of 10 kV. The formulation integrated a low-energy electromagnetic description with constrained electron-density and orbital stationarity conditions, interfacial interaction energies, and field-induced responses. A contact-dependent analytical potential was constructed by combining a Morse potential with dipolar, quadratic, and fourth-order electric-field contributions. Assuming an electrode separation of 3 cm and a uniform electric field, an applied voltage of 10 kV corresponded to a nominal electric-field strength of 3.333 × 105 V m-1. The combined polymer–zeolite interfacial contact model yielded a minimum interaction energy of -91.30 kJ mol-1 and a nominal-field-induced energy shift of -2.8459 J mol-1. Geometric relaxation increased the calculated polarizability from 310.000 to 313.4775 atomic units (a.u.). Central finite-difference calculations demonstrated the expected second-order dependence of truncation error on the electric-field step size, whereas a reduced quadratic energy model yielded a root mean square error (RMSE) of 0.36189 J mol-1 across six additional electric-field evaluation points. Compared with the relaxed second-order expansion, the fourth-order formulation reduced the maximum truncation error for the C5 configuration from 0.81463 to 0.001035 J mol-1. The theoretical derivations distinguished structural relaxation effects at the polymer–zeolite interface from biases in the estimated response coefficients arising from the omission of higher-order electric-field terms. The resulting equations established a reproducible representation of interfacial energetics and specified the variational potential required for subsequent density-functional extensions. However, quantitative calibration and independent validation of the proposed framework require atomistic DFT reference calculations of electronic energies, electron densities, and electric-field response properties.
Cervellere, M. Rosario, Qian, Xianghong, Ford, David M., Carbrello, Christina, Giglia, Sal, & Millett, Paul C. (2021). Phase-field modeling of non-solvent induced phase separation (NIPS) for PES/NMP/Water with comparison to experiments. Journal of Membrane Science, 619, 118779.
Colò, G., & Hagino, K. (2023). Orbital-free density functional theory: Differences and similarities between electronic and nuclear systems. Progress of Theoretical and Experimental Physics, 2023(10). https://doi.org/10.1093/ptep/ptad118
Damonte, G., Spotorno, R., Di Fonzo, D., & Monticelli, O. (2022). Multifunctional Porous Films Based on Polylactic Acid/Polycaprolactone Blend and Graphite Nanoplateles. ACS Applied Polymer Materials, 4(9), 6521–6530. https://doi.org/10.1021/acsapm.2c00923
Daub, C. D., & Kurtén, T. (2024). Effect of an Electric Field on the Structure and Stability of Atmospheric Clusters. The Journal of Physical Chemistry A, 128(3), 646–655. https://doi.org/10.1021/acs.jpca.3c07260
Gray, M., Bowling, P. E., & Herbert, J. M. (2022). Systematic Evaluation of Counterpoise Correction in Density Functional Theory. Journal of Chemical Theory and Computation, 18(11), 6742–6756. https://doi.org/10.1021/acs.jctc.2c00883
Gray, M., & Herbert, J. M. (2024). Assessing the domain-based local pair natural orbital (DLPNO) approximation for non-covalent interactions in sizable supramolecular complexes. The Journal of Chemical Physics, 161(5). https://doi.org/10.1063/5.0206533
Hernandez, A., & Mueller, T. (2023). Generalizability of functional forms for interatomic potential models discovered by symbolic regression. Physical Review Materials, 7(5), 053804. https://doi.org/10.1103/PhysRevMaterials.7.053804
Isidori, G., Wilsch, F., & Wyler, D. (2024). The standard model effective field theory at work. Reviews of Modern Physics, 96(1), 015006. https://doi.org/10.1103/RevModPhys.96.015006
Kirkpatrick, J., McMorrow, B., Turban, D. H. P., Gaunt, A. L., Spencer, J. S., Matthews, A. G. D. G., Obika, A., Thiry, L., Fortunato, M., Pfau, D., Castellanos, L. R., Petersen, S., Nelson, A. W. R., Kohli, P., Mori-Sánchez, P., Hassabis, D., & Cohen, A. J. (2021). Pushing the frontiers of density functionals by solving the fractional electron problem. Science, 374(6573), 1385–1389. https://doi.org/10.1126/science.abj6511
Kurniawan, R. A., & Chu, P. P.-J. (2024). The effect of electric field-assisted non-solvent induced phase separation method on PVDF membrane morphologies and performances. Polymer-Plastics Technology and Materials, 63(6), 703–715. https://doi.org/10.1080/25740881.2024.2302538
Li, L. (2021). Comprehensive investigations of interaction properties of polylactic Acid?Attapulgite composite by reactive molecular dynamics simulations and dispersion corrected DFT calculations. Current Applied Physics, 28, 78–86. https://doi.org/10.1016/j.cap.2021.05.001
Manholi, S., & Athiyanathil, S. (2022). Poly (??caprolactone)?based porous membranes for filtration applications—effect of solvents on precipitation kinetics, performance, and morphology. Journal of Applied Polymer Science, 139(10). https://doi.org/10.1002/app.51720
Neese, F. (2022). Software update: The ORCA program system—Version 5.0. WIREs Computational Molecular Science, 12(5). https://doi.org/10.1002/wcms.1606
Stanciakova, K., Louwen, J. N., Weckhuysen, B. M., Bulo, R. E., & Göltl, F. (2021). Understanding Water–Zeolite Interactions: On the Accuracy of Density Functionals. The Journal of Physical Chemistry C, 125(37), 20261–20274. https://doi.org/10.1021/acs.jpcc.1c04270
Wang, P., Gao, S., Chen, X., Yang, L., Cao, T., Fan, B., Liu, J., & Hu, X. (2022). Effect of PCL-b-PEG Oligomer Containing Ionic Elements on Phase Interfacial Properties and Aggregated Structure of PLA/PCL Blends. Macromolecular Research, 30(7), 438–445. https://doi.org/10.1007/s13233-022-0058-0
Zhang, H., Liu, S., You, J., Liu, C., Zheng, S., Lu, Z., Wang, T., Zheng, N., & Shao, B. (2024). Overcoming the barrier of orbital-free density functional theory for molecular systems using deep learning. Nature Computational Science, 4(3), 210–223. https://doi.org/10.1038/s43588-024-00605-8
Copyright (c) 2026 Muhammad Satya Putra Gantada, Agung Mataram

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-SA). that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.





