EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Energetic analysis of succinic acid in water droplets: insight into the size-dependent solubility of atmospheric nanoparticles

Chuchu Chen1,2, Xiaoxiang Wang1,6, Kurt Binder3, Mohammad Mehdi Ghahremanpour4,5, David van der Spoel4, Ulrich Pöschl2, Hang Su2, and Yafang Cheng1
Chuchu Chen et al.
  • 1Max Planck Institute for Chemistry, Minerva Research Group, Germany (
  • 2Max Planck Institute for Chemistry, Multiphase Chemistry, Mainz, Germany
  • 3Johannes Gutenberg University of Mainz, Institute of Physics, Mainz, Germany
  • 4Uppsala University, Department of Cell and Molecular Biology, Uppsala, Sweden
  • 5Yale University, Department of Chemistry, New Haven, USA
  • 6Southern University of Science and Technology, School of Environmental Science and Engineering, Shenzhen, China

Size-dependent solubility is prevalent in atmospheric nanoparticles, but a molecular level understanding is still insufficient, especially for organic compounds. Here, we performed molecular dynamics simulations to investigate the size dependence of succinic acid solvation on the scale of ~1-4 nm with the potential of mean forces method. Our analyses reveal that the surface preference of succinic acid is stronger for a droplet than the slab of the same size, and the surface propensity is enhanced due to the curvature effect as the droplet becomes smaller. Energetic analyses show that such surface preference is primarily an enthalpic effect in both systems, while the entropic effect further enhances the surface propensity in droplets. On the other hand, with decreasing droplet size, the solubility of succinic acid in the internal bulk volume may decrease, imposing an opposite effect on the size dependence of solubility as compared with the enhanced surface propensity. Meanwhile, structural analyses, however, show that the surface to internal bulk volume ratio increases drastically, especially when considering the surface in respect to succinic acid, e.g., for droplet with radius of 1 nm, the internal bulk volume would be already close to zero for the succinic acid molecule.

How to cite: Chen, C., Wang, X., Binder, K., Ghahremanpour, M. M., van der Spoel, D., Pöschl, U., Su, H., and Cheng, Y.: Energetic analysis of succinic acid in water droplets: insight into the size-dependent solubility of atmospheric nanoparticles, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6415,, 2021.