Interactions between paper and adsorbed molecules

Abstract

We have studied the geometry and energy involved in the interactions between adsorbed molecules and paper substrate, over a wide range of partial pressures. A two-dimensional virial equation of state was employed to evaluate the extent of interactions by the compressibility factor (Z). Data of H-bonded molecules (water and butan-l-ol) and of more weakly interacting ones (ndecane and dioxane) were selected from the literature. At low surface coverage, the compressibility factor Z exceeds 1, showing a deviation from ideality due to interactions, and reaches a maximum at a value close to the BET monolayer.As preliminary results we have measured by means of a differential microcalorimeter (Calvet) at 25~ the energy of interactions of water and n-heptane vapor on chromatographic grade Whatman paper.At very low coverage, the differential heats of adsorption of water on paper are higher than those of n-heptane adsorption on paper: 114 kJ mo1-1 > 77 kJ mo1-1. During the whole process of adsorption, in the first case, the specific interaction predominates, while in the second nonspecific interactions predominate i.e. the dispersion or Van der Waals forces.

Spectroscopic evaluation and characterization of different historical writing inks

“…The reasons for this destruction are not fully understood yet. It is believed that main degradation mechanism of paper degradation is following: inks prepared with different ingredients causes both acidic hydrolysis and catalyzed oxidation of cellulose [1][2][3][4][5]. The desire to conserve the paper necessitates the development of effective treatments methods, which can only be possible after determination of the chemical composition of inks [6,7].…”

Biomimetic Membranes with Aqueous Nano Chanels but without Proteins: Impedance of Impregnated Cellulose Ester Filters

“…One side of these channels is formed by IPM, whereas another, by polysaccharide cellulose chains with cation-exchange groups fixed on these chains. It is known that the differential heat of adsorption of water on Whatman paper is higher than that of n -heptane, which is determined by specific interactions . If free fatty acids were added into the impregnating liquid, H + ions are able to move simultaneously both carried by fatty acid anions in the oil and through the aqueous channels as free ions from one carboxylic group fixed on a polymer to another. , Interactions of these two mechanisms lead to the changes of a lag time before transport reaches the steady state…”

Biomimetic Membranes without Proteins but with Aqueous Nanochannels and Facilitated Transport. Minireview

“…Differential scanning calorimetry demonstrated that the freezing temperature of water in nitrocellulose-based membranes is below 0°C and depends on the pore size in a filter (0.05–0.45 μ) [ 62 ]. Note that heat of water adsorption on Whatman paper due to specific interactions is 114 KJ / mol , and it is much higher than that of medium-sized hydrocarbons [ 63 ].…”

“…The ordering of impregnating oils is distorted by nitrocellulose polymer chains penetrating through the membrane. These polymers (not only proteins but also polysaccharides) carry ion-exchange groups and interact with water [ 63 , 65 ], thus forming ion-selective aqueous channels with a thickness of a few nm. Polysaccharides are a common component of biological membranes, especially those of plant cells, including wood.…”