Direct observation of alkaline and enzymatic poly(ethylene terephthalate) hydrolysis via neutron reflectivity
Kinetics and mechanistic insights
Publication date
2025-05-29
Document type
Forschungsartikel
Author
Machatschek, Rainhard
Tarazona, Natalia A.
Balk, Maria
Göttsch, Frederike
Wei, Ren
Bornscheuer, Uwe T.
Moulin, Jean-François
Keller, Manuela
Schneider, Nicole
Gutfreund, Philipp
Müller, Martin
Mangiapia, Gaetano
Organisational unit
Scopus ID
Publisher
Elsevier BV
Series or journal
Journal of Colloid and Interface Science
ISSN
Periodical volume
698
Article ID
138021
Peer-reviewed
✅
Part of the university bibliography
✅
Language
English
Keyword
Enzymatic hydrolysis
Neutron reflectivity
PET
Abstract
One of the challenges in achieving industrial enzymatic depolymerization of poly(ethylene terephthalate) (PET) is the rapid loss of catalytic activity leading to incomplete polymer hydrolysis. While there are several possible explanations for this phenomenon, there is a lack of methods that can measure polymer hydrolysis directly, which makes it challenging to reliably infer mechanistic details. Here, we introduce neutron reflectivity of polymer thin films as a method that allows for direct assessment of the hydrolysis rate of polymers like PET. Through matching and variation of the isotopic contrasts, one can directly observe the reaction kinetics, while simultaneously obtaining structural information on the polymer/enzyme/water system. We show that the Michaelis-Menten theory describes well the enzymatic chain scission kinetics, whereas the alkaline one follows a (pseudo)-first order kinetics. At the concentrations used in the experiments, the areal density of enzymes at the polymer surface is very low, ruling out surface passivation or overcrowding as inhibition mechanisms.
Description
This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/).
Version
Published version
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