Chitosan Eco-Friendly Approach to Oil Spill Cleanup: A Combined 2D TD-NMR Relaxation and Computational Modeling Study

Kock F.; Valdiviezo J.; Cirilo E.; Sifuentes J.; Nakamatsu J.; Souza A.; Castro E.; Barbosa L.; Colnago L. · Journal of Polymers and the Environment (2026) · DOI: 10.1007/s10924-025-03722-1

Resumen

This work investigates the molecular interaction between chitosan, an effective and eco-friendly biopolymer, and crude oil components within petroleum emulsions. This mechanistic investigation combines 2D TD-NMR relaxation and computational modeling to understand chitosan’s role as an adsorbent and demulsifier for applications in environmental remediation. We applied a medium molecular mass chitosan to a series of six petroleum emulsions, spanning a representative range of medium and heavy crude oils (viscosities from 32.52 to 182.07 mm2.s-1 at 20 °C). The 2D D-T2 correlation maps were generated using the PFG-CPMG (Pulsed Field Gradient-Carr-Purcell-Meiboom-Gill) sequence to resolve the changes in oil and water mobility following chitosan addition. The key result is the observation of a characteristic shift in the diffusion coefficient (D) and transverse relaxation time (T2) of the oil component upon chitosan introduction. This shift provides direct evidence of the molecular interaction and the disruption of the emulsion stabilizing film. Furthermore, molecular modeling confirms strong water binding, complementing the TD-NMR findings. Overall, the study successfully demonstrates the utility of TD-NMR and molecular dynamics for mechanistic assessment, providing crucial, direct insight into the demulsification role of chitosan within petroleum emulsions. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.

Instituciones: Pontificia Universidad Católica del Perú