Energetic and Structural Characterizations of the PET–Water Interface as a Key Step in Understanding Its Depolymerization

Abstract

We report molecular simulations of the interaction between poly­(ethylene terephthalate) (PET) surfaces and water molecules with a short-term goal to better evaluate the different energy contributions governing the enzymatic degradation of amorphous PET. After checking that the glass transition temperature, density, entanglement mass, and mechanical properties of an amorphous PET are well reproduced by our molecular model, we extend the study to the extraction of a monomer from the bulk surface in different environments, i.e., water, vacuum, dodecane, and ethylene glycol. We complete this energetic characterization by the calculation of the work of adhesion of PET surfaces with water and dodecane molecules and by the determination of the contact angle of water droplets. These calculations are compared with experiments and should help us to better understand the enzymatic degradation of PET from both the thermodynamic and molecular viewpoints.

Probing Enzymatic PET Degradation: Molecular Dynamics Analysis of Cutinase Adsorption and Stability

“…In the case of the PET−water interface, atomistic simulations have been conducted to predict the work of adhesion between water and the amorphous PET surface. 27 These simulations provide insights into the strength of interactions between these two media. Additionally, the free-energy cost associated with extracting a monomer from PET material in various environments including water, dodecane, EG, and vacuum has been assessed.…”

“…14,36−39 The present study aims to address the biodepolymerization of PET in a holistic manner, filling the existing gap in understanding of different phenomena and the determination of various properties of PET biodegradation. Building upon a comprehensive investigation of the PET−water interface 27 to assess the strength of interactions between water and PET, as well as the energy costs associated with extracting PET monomers in various solvents, this work focuses on probing the adsorption of the LCC-ICCG enzyme onto the PET surface. The adsorption process is elucidated by calculating the interaction energy and examining changes in the enzyme's structural and hydration properties compared to bulk water conditions.…”

“…It allows for an adapted description of interactions, tailored to the specific process and properties under investigation. In the case of the PET–water interface, atomistic simulations have been conducted to predict the work of adhesion between water and the amorphous PET surface . These simulations provide insights into the strength of interactions between these two media.…”