Due to their intrinsic interactions with cellulose in nature, hemicelluloses constitute interesting candidates for physical modification of (nano)cellulose via polymer adsorption. However, harnessing the full potential of this bioinspired approach in the design of advanced materials requires understanding of the structure-property-function relationships and component interconnections in the plant cell wall. We aim to elucidate the interactions of grass cell wall hemicelluloses, i.e., mixed-linkage glucans (MLGs) with nanocellulose substrates to reveal the driving forces for adsorption and the influence of different co-solute ions on the interactions. Due to their ability to efficiently gel and hydrate nanocellulosic networks, MLGs have previously been investigated e.g. as components for nanocellulose-based all-polysaccharide hydrogels in contact with living cells. The prior interfacial investigation has shown that MLG adsorption on nanocellulose surfaces somewhat deviates from the well-known polyelectrolyte adsorption theories. Here, we employ isothermal titration calorimetry (ITC) in conjunction with a surface sensitive approach using quartz crystal microbalance with dissipation monitoring (QCM-D) to study the thermodynamics of interaction and the hemicellulose adsorption process, respectively. To also elaborate on the behaviour of MLGs in solution in different salt environments, light scattering techniques are used. Overall, the research explores the possibility of utilizing MLGs for tuning the water interactions and viscoelastic properties of the nanocellulose networks, as well as using chaotropic ions like nitrates as a tool to further control the materials’ swelling and water uptake.

<b><i>Figure 1.</i></b><i> Investigation of thermodynamic parameters and interfacial phenomena of mixed-linkage glucan (MLG) and nanocellulose interactions via isothermal titration calorimetry (ITC) in conjunction with surface sensitive techniques, such as quartz crystal microbalance with dissipation monitoring (QCM-D). </i>

Figure 1. Investigation of thermodynamic parameters and interfacial phenomena of mixed-linkage glucan (MLG) and nanocellulose interactions via isothermal titration calorimetry (ITC) in conjunction with surface sensitive techniques, such as quartz crystal microbalance with dissipation monitoring (QCM-D).

Vladimir Grachev

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