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.