Nanoscale hygromechanical behavior of lignin

Hess, Kristen M.; Killgore, Jason P.; Srubar, Wil V.

doi:10.1007/s10570-018-2045-3

Cited by 20 publications

(10 citation statements)

References 60 publications

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“…The estimated values of the C parameter were always slightly higher than K in the corresponding isotherms (Table 3). This suggests that monolayer water molecules are bound much more strongly than those with multilayer bonding [61]. Moreover, slightly higher values of the C parameter than K indicate a slight difference in the heat of sorption of the monolayer as compared to the multilayer [60,62].…”

Section: Sorption Behavior Derived From Experimental Gab Sorption Isothermsmentioning

confidence: 99%

The Effect of Chitosan Type on Biological and Physicochemical Properties of Films with Propolis Extract

et al. 2021

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The aim of the research was to determine the influence of chitosan type and propolis extract concentration on biological and physicochemical properties of chitosan-propolis films in terms of their applicability in food packaging. The films were prepared using three types of chitosan: from crab shells, medium and high molecular weight and propolis concentration in the range of 0.75–5.0%. The prepared polysaccharide films were tested for antimicrobial properties, oxygen transmission rate (OTR) and water vapor transmission rate (WVTR). Moreover, sorption tests and structural analysis were carried out. Microbiological tests indicated the best antimicrobial activity for the film consisting of high molecular weight chitosan and 5.0% propolis extract. Both the type of chitosan and propolis concentration affected transmission parameters—OTR and WVTR. The best barrier properties were recorded for the film composed of high molecular weight chitosan and 5.0% propolis extract. The results of sorption experiments showed a slight influence of chitosan type and a significant effect of propolis extract concentration on equilibrium moisture content of tested films. Moreover, propolis extract concentration affected monolayer water capacity (Mm) estimated using the Guggenheim, Anderson and de Boer (GAB) sorption model. The obtained results indicate that chitosan films with an addition of propolis extract are promising materials for food packaging applications, including food containing probiotic microorganisms.

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Section: Sorption Behavior Derived From Experimental Gab Sorption Isothermsmentioning

confidence: 99%

The Effect of Chitosan Type on Biological and Physicochemical Properties of Films with Propolis Extract

et al. 2021

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“…The observed values of C GAB were always significantly higher than K GAB in corresponding isotherms (Table 1). This suggests that monolayer water molecules might be much stronger bound than those with multilayer bonding (e.g., Hess et al 2018). Thermal modification increased C GAB for isotherms both in adsorption and desorption as well as for both size fractions of particles.…”

Section: Sorption Isothermsmentioning

confidence: 99%

“…This was observed for untreated and thermally modified wood as well as for both size fractions of wood dust. Hess et al (2018) attributed differences in C GAB values for desorption and adsorption to sorption hysteresis. The coefficient K GAB indicates the difference between the free enthalpy of multilayer water molecules and bulk water (Timmermann 2003).…”

Section: Sorption Isothermsmentioning

confidence: 99%

Sorption and diffusion properties of untreated and thermally modified beech wood dust

2021

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Dynamic water vapor sorption experiments were carried out using beech wood dust (from untreated and thermally modified wood) of two-particle sizes, (< 25 and 80–250 µm), obtained from abrasive sanding. Sorption isotherms were parameterized with the GAB and GDW models. Dust from thermally modified wood had significantly lower equilibrium moisture content compared to dust from untreated material, due to the reduction in primary sorption sites in treated material. The observed changes were quantified by the coefficients of the GAB and GDW models. Thermal modification and size of wood dust particles had no influence on binding energy of water molecules being linked to the secondary sorption sites. Water diffusivity decreased significantly with increasing moisture content, but only for monolayer sorption. For higher moisture content values, water diffusivity was practically independent of moisture content. These results were found for untreated and thermally modified material as well as for both dust size fractions. The influence of thermal modification on water diffusivity was unclear, which is attributed to the diffusion model, which represents dust particles as spheres and assumes instant hygroscopic equilibrium. Overall, this study indicates that the effectiveness of filtration processes likely depends strongly on sorption and diffusion properties of wood dust only at low moisture contents within the hygroscopic range.

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“…The relative stable sorption behavior of SCWH lignin implies a less moisture dependent hydromechanical response [69], which makes this material promising as reinforcement in polymer composites [70]. The adsorption characteristics have a close relationship with the solution behaviors of lignosulfonates [71].…”

Section: Automated Vapor Sorption (Avs) Analysismentioning

confidence: 99%

Characterization of Wood-based Industrial Biorefinery Lignosulfonates and Supercritical Water Hydrolysis Lignin

Hemmilä

Hosseinpourpia

Αδαμόπουλος

et al. 2019

Waste Biomass Valor

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Understanding the properties of any particular biorefinery or pulping residue lignin is crucial when choosing the right lignin for the right end use. In this paper, three different residual lignin types [supercritical water hydrolysis lignin (SCWH), ammonium lignosulfonate (A-LS), and sodium lignosulfonate (S-LS)] were evaluated for their chemical structure, thermal properties and water vapor adsorption behavior. SCWH lignin was found to have a high amount of phenolic hydroxyl groups and the highest amount of β-O-4 linkages. Combined with a low ash content, it shows potential to be used for conversion into aromatic or platform chemicals. A-LS and S-LS had more aliphatic hydroxyl groups, aliphatic double bonds and C=O structures. All lignins had available C3/C5 positions, which can increase reactivity towards adhesive precursors. The glass transition temperature (Tg) data indicated that the SCWH and S-LS lignin types can be suitable for production of carbon fibers. Lignosulfonates exhibited considerable higher water vapor adsorption as compared to the SCWH lignin. In conclusion, this study demonstrated that the SCWH differed greatly from the lignosulfonates in purity, chemical structure, thermal stability and water sorption behavior. SCWH lignin showed great potential as raw material for aromatic compounds, carbon fibers, adhesives or polymers. Lignosulfonates are less suited for conversion into chemicals or carbon fibers, but due to the high amount of aliphatic hydroxyl groups, they can potentially be modified or used as adhesives, dispersants, or reinforcement material in polymers. For most value-adding applications, energy-intensive purification of the lignosulfonates would be required. Graphic Abstract

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Nanoscale hygromechanical behavior of lignin

Cited by 20 publications

References 60 publications

The Effect of Chitosan Type on Biological and Physicochemical Properties of Films with Propolis Extract

The Effect of Chitosan Type on Biological and Physicochemical Properties of Films with Propolis Extract

Sorption and diffusion properties of untreated and thermally modified beech wood dust

Characterization of Wood-based Industrial Biorefinery Lignosulfonates and Supercritical Water Hydrolysis Lignin

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