Self‐Assembly and Intermolecular Forces When Cellulose and Water Interact Using Molecular Modeling

Abstract

Cellulose chains are linear and aggregation occurs via both intra- and intermolecular hydrogen bonds. Cellulose has a strong affinity to itself and toward materials containing hydroxyls groups. Based on the preponderance of hydroxyl functional groups, cellulose is very reactive with water. At room temperature, cellulose chains will have at least a monomolecular layer of water associated to it. The formation of hydrogen bonds at the cellulose/water interface is shown to depend essentially on the adsorption site, for example, the equatorial hydroxyls or OH moieties pointing outward from the cellulose chains. The vdW forces also contribute significantly to the adsorption energy. They are a considerable cohesive energy into the cellulose network. At the surface of the cellulose chains, many intermolecular hydrogen bonds of the cellulose chains are lost. However, they are compensated by hydrogen bonds with water molecules. Electronic clouds can be distorted and create electrostatic dipoles. The large antibonding electron cloud that exists around the glucosidic bonds produces an induced polarization at the approach of water molecules. The electron cloud can be distorted and create an electrostatic dipole. It applies to the total displacement of the atoms within the material. Orbitals play a special role in reaction mechanism. Hydrophilic/hydrophobic nature of cellulose is based on its structural anisotropy. Cellulose-water interactions are exothermic reactions. These interactions may occur spontaneously and result in higher randomness of the system. They are denoted by a negative heat flow (heat is lost to the surroundings). Energy does not need to be inputted in order for cellulose-water interactions to occur.

Hierarchical chirality transfer in the growth of Towel Gourd tendrils

“…For example, hemicellulose molecules in the cell walls can self-assemble in cholesteric liquid crystals, which, in turn, mediate the assembly of cellulose microfibrils into helical patterns through hydrogen bonds between hemicelluloses and cellulose chains2627. During the swelling/deswelling and growth processes, some intermolecular hydrogen bonds may be broken with the appearance of water molecules28, which may also induce the reorientation of cellulose fibrils. Thus a tendril will assume a helical shape due to the intrinsic torsion.…”

Decoration of Nanofibrous Paper Chemiresistors with Dendronized Nanoparticles toward Structurally Tunable Negative‐Going Response Characteristics to Human Breathing and Sweating

“…Modeling and Simulation : The theoretical modeling and simulation were performed to assess the interparticle spatial and interaction properties. The DMol3 tool and Amorphous cell from Accelrys Materials Studio 6.0 was used to build the interparticle interaction models. The simulation of the optical absorption and the enhancement of the electric field intensity in the dielectric environment surrounding AuNPs due to the effect of their localized surface plasmon resonances was performed using the MNPBEM toolbox based on the boundary element method, which has been demonstrated in our recent work on dimers of interparticle‐linked gold nanoparticles .…”

Chemical and multi-physical characterization of agro-resources’ by-product as a possible raw building material

“…So, many intermolecular hydrogen bonds are broken in the cellulose to allow new connections between cellulose chains and water molecules, leading to water bond. Water absorption causes swelling of agro-resources, hence their volume increases ( Figure 41) (Chami Khazraji and Robert, 2013;Van Der Reyden, 1992). Figure 42 gives moisture buffer value versus thermal conductivity in order to find out the best valuation on hygrothermal point of view.…”