Kinetics of Organic Volatile Desorption from Cellulose-Based Materials

This contribution investigates the mathematical description
of
the release of volatile organic compounds (VOCs) from cellulose-based
porous materials, particularly paper, extensively used in food packaging.
Prior research has shown that migration kinetics may be significantly
influenced by factors such as substance volatility, its chemical structure
and polarity, ambient humidity, and interactions with the fibrous
matrix of paper. While some deterministic models, based on the second
Fick’s law, have been used to describe migration, these diffusion
models often fall short when applied to fibrous cellulosic materials
like paper. The highly adaptive empirical Weibull model has been employed
to address these limitations. However, this model also shows its limitations
in terms of the physical interpretation of the empirically derived
fitting parameters. This contribution proposes to use a mathematical
model based on pseudo-first-order kinetics to quantitatively predict
the desorption of VOCs from paper into ambient air. The model is based
on Langmuir theory and offers a physical interpretability of its parameters,
namely, sorption constants. In focusing on VOC transport and emission
under isothermal and isobaric conditions, it differs from isothermal
adsorption–desorption models. Experimental data for 10 model
compounds are used to validate the proposed model and provide insights
into the role of polarity, size, chemical structure, and volatility
in desorption kinetics. The study demonstrates that the desorption
of VOCs from paper can be effectively modeled using pseudo-first-order
kinetics, which captures variations across different substances and
environmental conditions. These findings provide valuable insights
into the kinetics of VOC desorption and its dependence on compound
properties, which can inform food packaging design and preservation
strategies.