Impact of the particle mixing state on the hygroscopicity of internally mixed sodium chloride–ammonium sulfate single droplets: a theoretical and experimental study

Humidograms of mixed NaCl/(NH₄)₂SO₄ particles show two or three transitions depending on the initial molar composition. Up to five solid salts can coexist within the dry particles: NaCl, (NH₄)₂SO₄, NH₄Cl, Na₂SO₄ and NH₄NaSO₄·2H₂O.