Molecular dynamics investigation on the deliquescence of NH4Cl and NH4NO3 nanoparticles under atmospheric conditions

Abstract

In this study, the deliquescence of NH₄Cl and NH₄NO₃ nanoparticles under atmospheric conditions was modeled by molecular dynamics simulation in order to investigate the effects of nanoparticle size and temperature. The physical significance of the method of this work is its lower computational cost of the calculations in comparison with the previous studies, without any considerable effect on the accuracy of the results. The results showed that an increase of the nanoparticle size decreases deliquescence relative humidity in such a way that this decrease can be fitted to an exponential decay for both NH₄Cl and NH₄NO₃ nanoparticles. Also, increase of temperature decreases deliquescence relative humidity which can be described by the wettability of the nanoparticle. Moreover, NH₄NO₃ nanoparticles were found to have more ability to deliquescence in atmospheric conditions than NH₄Cl ones and hence maybe could be considered more by environmental scientists for their possible influences on the ecosystem of the earth and future attempts to reduce their concentration in the atmosphere.