Effect of Dihydric Alcohol on the Vapor-Liquid Phase Equilibrium of Nicotine-Containing Ternary Systems

In order to investigate the release behavior of the main components of atomized vapor in heated tobacco products, the ternary systems of nicotine/water/diol and nicotine/glycerol/diol are constructed using diol (1,2-propanediol, 1,3-propanediol, ethylene glycol) as atomizers. These systems were studied by the conductor-like screening model for segment activity coefficient (COSMO-SAC) model at constant temperature. It is found that the vapor-liquid equilibria of different diols are very similar to those of nicotine/water/diols. The content of nicotine in the gas phase increases initially and then decreases with the increase in water content in the liquid phase. When the mole fraction of water is either low or high, a decrease in temperature favors the vaporization and release of nicotine. The capacity of 1,3-propylene glycol to facilitate nicotine vaporization exceeds that of 1,2-propylene glycol. For the nicotine/glycerol/diols system, the gas-liquid phase equilibrium of different glycols demonstrates generally consistent patterns. Glycerol can obviously promote the vaporization of nicotine. In the whole concentration range, the ability to promote nicotine vaporization from high to low was 1,3-propylene glycol > ethylene glycol > 1,2-propylene glycol, and a lower temperature enhances the vaporization of nicotine. The results provide theoretical support for the formulation design and optimization of novel tobacco products.