Analysis of water adsorption by wood using the Guggenheim-Anderson-de Boer equation

Bratasz, Łukasz; Kozłowska, Anna; Kozłowski, Roman

doi:10.1007/s00107-011-0571-x

Cited by 83 publications

(55 citation statements)

References 10 publications

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“…The modified GAB model gave a better fit than the original model for the experimental data obtained from the moisture adsorption isotherms in the range from 0.10 to 0.90 a w (Table 3). As the parameters of the GAB equation are based on the physical phenomena involved in water adsorption by hydrophilic materials, it is considered the most suitable model to describe experimental data (Bratasz et al, 2012;Figura & Teixeira, 2007;Furmaniak et al, 2007;Lavoyer et al, 2013;Medeiros et al, 2006;Souza et al, 2015;Timmermann et al, 2001;Zhang & Han, 2008).…”

Section: Modeling Of Experimental Datamentioning

confidence: 99%

Modelling the effect of temperature on the water sorption isotherms of chitosan films

2016

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The interaction of the water molecules from the environment with foods and other materials can be evaluated using sorption isotherms. Films and biodegradable films are susceptible to changes in their functional characteristics due to adsorbed water. The amount of moisture that biodegradable films can adsorb depends on the temperature, relative humidity of the storage area and chemical composition. Several mathematical models can be used to describe the behavior of sorption isotherms in biodegradable films and some of them have been modified to include the temperature parameter into the equation. In this research, the original and modified BET, GAB, Halsey, Henderson and Dswin models were assessed to determine their suitability describing the behavior of moisture adsorption isotherms of chitosan films at 15, 20, 25 and 30 °C. The modified models of GAB, Dswin and Halsey gave the best fit to the experimental sorption data of the chitosan films, with R 2 values higher than 0.97 demonstrating that those models describe better the sorption isotherms at the temperatures studied.Keywords: chitosan film; moisture adsorption isotherm; GAB model. Practical Application:The knowledge of the relationship between the equilibrium moisture content, equilibrium relative humidity and temperature is very important in order to describe the effect of water activity on storage of foods. Several mathematical models were used to describe the water sorption behavior of chitosan edible films involving water activity, moisture content and temperature.

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Section: Modeling Of Experimental Datamentioning

confidence: 99%

Modelling the effect of temperature on the water sorption isotherms of chitosan films

2016

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“…The isotherms were modelled using the Guggenheim, Anderson and Boer-Dent (GAB) expression. This model is particularly appropriate for food materials and widely used for multi-layer materials such as wood (Bratasz et al 2011). GAB system general equation is reported in eqn.…”

Section: Moisture Relations Assessmentmentioning

confidence: 99%

Kinetic analysis of poplar wood properties by thermal modification in conventional oven

Marcon¹,

Goli²,

Matsuo-Ueda³

et al. 2018

iForest

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The kinetics of several poplar (Populus alba L.) wood properties during thermal modification conducted in conventional oven with air recirculation were analysed and modelled in this paper. A wide range of properties was assessed, such as: equilibrium moisture content, sorption diagram, shrinkage coefficients, specific shrinkage coefficients, mass loss, modulus of elasticity, strength and colour. The tests were executed at different temperatures ranging from 90 °C to 180 °C and with different durations. The time-temperature equivalency was checked and property modifications over time analysed through master curves in order to obtain a general model connecting together properties, treatment temperature and duration. Different activation energies arising from each property evolution with treatment temperature and duration are provided showing that every modification could occur with different kinetics.

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“…Experimental studies using this type of isotherm can be found mainly on (multilayer-like) adsorption, e.g. water on synthetic and natural polymers, starch, wood or food [33][34][35][36][37]. To the best of our knowledge, there are only two studies applying a multilayer-like adsorption model like GAB or BET to the uptake of phosphoric acid and water in polybenzimidazole [24,38].…”

Section: Limiting Cases For Low and High Concentrations Of The Dopingmentioning

confidence: 97%

Uptake of protic electrolytes by polybenzimidazole-type polymers: absorption isotherms and electrolyte/polymer interactions

Korte¹,

Conti

Wackerl³

et al. 2015

J Appl Electrochem

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Polybenzimidazole (PBI) membranes doped with phosphoric acid are used as proton-conducting membrane in high-temperature polymer electrolyte fuel cells. There is no general model for the thermodynamics of the absorption process over the whole accessible doping range for all published data. The interactions between H 3 PO 4 and polymer chains, the polycondensation equilibria of H 3 PO 4 and the implications on proton conductivity are still largely unknown. In this study, we demonstrate that the uptake of a protic electrolyte by a polymer with basic moieties, i.e. a PBI-type polymer, can be described satisfactorily with a BET-like absorption isotherm. The absorption equilibria of the uptake process are analysed using literature data on the H 3 PO 4 , H 2 SO 4 and HClO 4 uptake of non-crosslinked m-PBI and AB-PBI as well as using our own investigations on the H 3 PO 4 uptake of a commercial crosslinked PBI derivative, Fumapem AM-55. In addition to the thermodynamic data of the absorption process, Raman data on m-PBI taken from the literature and our own Raman investigations on Fumapem AM-55 are taken into account. It is possible to correlate domains in the absorption isotherms with specific features in the Raman spectra. Two stages for the uptake of a protic electrolyte can be distinguished: (i) the protonation of the polymer chains and thus coulombic interactions with the electrolyte anions, (ii) the formation of H bonds directly with the chains and with electrolyte molecules that are still absorbed.

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Analysis of water adsorption by wood using the Guggenheim-Anderson-de Boer equation

Cited by 83 publications

References 10 publications

Modelling the effect of temperature on the water sorption isotherms of chitosan films

Modelling the effect of temperature on the water sorption isotherms of chitosan films

Kinetic analysis of poplar wood properties by thermal modification in conventional oven

Uptake of protic electrolytes by polybenzimidazole-type polymers: absorption isotherms and electrolyte/polymer interactions

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