Kinetics and Thermodynamics of Hemicellulose Adsorption onto Nanofibril Cellulose Surfaces by QCM-D

Abstract

The adsorption of hemicellulose derived from bagasse onto nanofibril cellulose has been studied in terms of kinetics and thermodynamics. In situ monitoring of bagasse hemicellulose with different molecular weights onto the nanofibril cellulose surfaces has been investigated using quartz crystal microbalance and dissipation. Then, the adsorption kinetics and thermodynamic properties were analyzed. Also, the sorption behavior and the adsorption layer properties were quantified in aqueous solutions. The maximum adsorption mass was 2.8314 mg/m2 at a concentration of 200 mg/L. Also, compared with that of the low-molecular-weight hemicellulose, the adsorption capacity of the high-molecular-weight hemicellulose was higher, and the adsorption rate changed faster and could reach an equilibrium in a shorter time. The intraparticle diffusion kinetic model represented the experimental data very well. Therefore, the kinetics of hemicellulose on the fiber adsorption was commonly described by a three-stage process: mass to transfer, diffusion, and equilibrium. The Gibbs energy change of the adsorption of hemicellulose was found to range from −20.04 to −49.75 kJ/mol at 25 °C. The entropy change was >0. It was found that the adsorption was spontaneous, and the adsorbed mass increased with the increase in temperature. This strengthened the conclusion that the adsorption process of the bagasse hemicellulose on the NFC was driven by the increase in entropy caused by the release of water molecules due to hydrophobic interaction or solvent reorganization.

Hemicellulose and Nano/Microfibrils Improving the Pliability and Hydrophobic Properties of Cellulose Film by Interstitial Filling and Forming Micro/Nanostructure

“…In Figure 6 c, many dense white micro/nanostructures on the surface of the film exist, which may be because the exposed hemicellulose was adsorbed on the surface of nanocellulose driven by entropy [ 41 ]. As previously [ 42 ] reported, the xylan is likely to assemble into nanoparticulate aggregates in solution first and it was deposited like this onto the cellulose fibrils, forming a large number of white micro/nanoprotrusions consistent with the C-25 film surface 3D image analysis in Figure 6 d,e.…”

Quartz crystal microbalance with dissipation (QCM-D) as a way to study adsorption and adsorbed layer characteristics of hemicelluloses and other macromolecules on thin cellulose films: A Review

“…Wang et al (2017) found that mannan with fewer side chains and lower molecular weight adsorbed more onto cellulose. Yao et al (2021) extracted hemicellulose of different molecular weights by hydrothermal and alkaline extraction methods. The adsorption capacity of high molecular weight hemicellulose was high, the adsorption rate was faster, and the adsorption equilibrium was reached in a shorter time.…”

“…The study of interactions is an essential part of many fields, for example, in the field of biomass, new materials can be developed, and utilization rate can be improved, etc. For this reason, it is particularly important to develop means of monitoring interactions, such as atomic force microscopy (Yao et al 2021), dynamic light scattering (Arumughan et al 2022), X-ray diffractometers (Wang et al 2017), and contact angle measurement (Zhang et al 2020). For cellulose and hemicellulose, the structure of the surface of the two is more complex, the difference in quality change during adsorption is very small, and most traditional detection tools can only detect the results after adsorption and cannot monitor the adsorption process in real time.…”

“…In the study of the behavior of macromolecules adsorption onto cellulose, it is difficult to measure untreated cellulose with QCM-D, so it is necessary to cover the sensor of QCM-D with a layer of film with good performance, uniformity, and stability. The common film preparation methods are the spin coating method (SC) (Villares et al 2015;Jaafar et al 2019;Yao et al 2021) and the Langmuir-Blodgett method (Tammelin et al 2007).…”

“…Many scholars have used QCM-D and other research instruments to study the molecular dynamics of adsorption, but due to the complexity and diversity of hemicellulose molecules and the large molecular weight distribution range, so far, no study has shown the main factors affecting the adsorption of hemicellulose. Yao et al (2021) used QCM-D to study the adsorption of arabino-4-O-methylglucuronoxylan of different molecular weights by alkaline and hydrothermal extraction methods on CNF. Adsorption kinetics was studied with QCM-D.…”