Adsorption and diffusion properties of tobacco composition and additive: a multiscale theoretical study

Temperature, concentration and pore size constitute critical factors influencing adsorption and diffusion in tobacco. Investigating the adsorption and diffusion behavior of tobacco not only advances fundamental theory but also provides practical guidance for the tobacco industry to optimize cigarette quality and performance through adjustments in production conditions. This study reports a multiscale simulation framework exploring the adsorption and diffusion of water, propylene glycol, glycerol and nicotine under the influence of these key factors. First-principles density functional theory calculations reveal the preference of H₂O to adsorb on O-top rather than H-top sites due to weak hydrogen bond interactions. Additionally, molecular dynamics simulations demonstrate that with increase in temperature, the diffusion properties of H₂O and other components enhance, attributed to intensified thermal vibrations and increased kinetic energy of the adsorbent. Intriguingly, with increase in concentration, the diffusion properties of all adsorbents initially increase and then decrease, intricately linked to hydrogen bond effects on system stability and the availability of accommodation space in the porous structure of cellulose. Furthermore, as pore size enlarges, the diffusion of adsorbents significantly increases due to the expansion of free space. In summary, the objective of this study is to provide a profound theoretical understanding for the cigarette industry, thereby contributing to the improvement of cigarette quality and flavor.