Roles of Paper Composition and Humidity on the Adhesion between Paper Sheet and Glass: A Molecular Dynamics Study

Abstract

Understanding adhesion behavior between paper materials and inorganic substrate is important to minimize surface contamination by paper fragments. In this work, we investigate adhesion mechanisms between paper sheet and glass in terms of molecular interaction. Molecular dynamics simulations are employed to calculate adhesion force between paper sheet and the silica glass surfaces. Pulling and sliding tests are simulated to find the effects of the paper compositions such as mannan, glucan, and glucuronoxylan and humidity on the adhesion. Simulation results reveal that crystalline cellulose film of mannan unit (uni-directional hydroxyl groups) shows higher adhesion than that of glucan unit (bi-directional hydroxyl groups). Also, addition of just a few glucuronoxylan (xylan) hemicellulose molecules on the cellulose film remarkably enhances adhesion force, because of carboxylic acid groups with strong polarity in xylan. In addition, introduction of humidity leads to a further increase of adhesion due to hydrogen bonds bridged by water molecules. The adhesion force is maximized around 10 H2O/nm2 because as the humidity increases, hydrogen bond interactions are saturated, whereas the Van der Waals interactions decrease due to thicker water layer. It is discussed that consideration of the capillary force for paper may result in different adhesion response that reflects more realistic situation.

Review on Interfacial Bonding Mechanism of Functional Polymer Coating on Glass in Atomistic Modeling Perspective

“…Park et al investigated the interface between glass and paper materials, wherein the paper belongs to the family of natural polymers and its chemical structure is a combination of rigid and flexible polymeric parts [ 32 ]. Figure 7 a,b describes chemical structures of two polymeric ingredients of the paper material.…”

“…(ii) In the copolymer case, some polar functional groups exposed to the interface strongly interact with hydroxyl groups on the silica surface, which finally contribute to the adhesion at some extent. It is also worth revisiting the paper–silica interface case and compare the above results with it [ 32 ]. Figure 9 shows an overall comparison of adhesion forces of cellulose and cellulose–xylan composite on silica glass using pulling and sliding tests.…”

“…In addition to the comparison between dry and wet conditions, it is also interesting to control the amount of water molecules absorbed in the silica surface, which can be corresponding to atmospheric humidity. In the study by Park et al, the effect of gradual change of relative humidity on the adhesion of paper-silica interfaces was also studied [ 32 ]. Various amount of water molecules in the range of 0 to 80 H 2 O/nm 2 , where 5 and 20 H 2 O/nm 2 roughly corresponds to relative humidity of 15% and 75%, respectively, were introduced to the paper-silica interface, and the adhesion mechanism was analyzed [ 57 ].…”

“…MD simulation clarifies nanoscale characteristics of the interface, such as the adhesion strength, thickness, and surface density of the polymer film [ 30 ]. Furthermore, for both cases of bonded and non-bonded interaction, atomistic modeling can artificially control the extrinsic conditions, such as the surface morphology of the glass substrate and relative humidity, to study their unique effects on the adhesion [ 29 , 30 , 31 , 32 , 33 ].…”