Charge transport multiscale modelling for bridging material properties to insulation performance: case study of moisture deterioration at cellulose–oil interface

To address this problem, we propose a versatile multiscale CT modelling framework integrating

Molecular Dynamics (MD) and Quantum Chemistry (QC) calculations. MD enables the construction of realistic molecular morphologies and the analysis of deterioration under various stresses, while QC provides the electronic information required for CT modelling. Through multiscale mapping between MD and QC, material properties and insulation performance can be investigated collaboratively.

Based on this framework, a realistic cellulose–oil interface morphology is constructed to study moisture deterioration. Water molecules initially cluster in the oil phase, then diffuse toward the hemicellulose interface, and finally adsorb individually at the cellulose fibril surface through hemicellulose–water hydrogen bonding. Although water molecules do not directly facilitate CT because of their high site energies, they reduce the interfacial energy barrier through molecular-environment polarization. This promotes CT across the interface, increases conductivity, and weakens insulation performance. The proposed framework provides mechanism-level insight and practical guidance for status assessment and material modification, and can be extended to other dielectric materials under complex operational stresses.