Crystallization of Ammonium Nitrate Under Organised Monolayers at Air-Aqueous Interface

The crystallization of NH₄NO₃ under compressed Langmuir monolayers of carboxybe-taine(C₂₂N₃COO^-),C₂₂H₁₅N(CH₂)₃(CH₂)₃COO^--C₂₂N₃COO^-] and dioleoyl-L-a-lecithin(DOPC) was studied by means of π-A. ΔV-A and fluorescence microscopy (FM). The surface pressure, surface potential and molecular area of C₂₂N₃COO^- were decreased on the NH₄NO₃ solution subphase. The surface pressure and molecular area of DOPC was increased. The surface potential of DOPC was decreased. We can directly observe the surface crystallization of NH₄NO₃ by FM. The results revaled that C₂₂N₃COO^- monolayer was the promoter of NH₄NO₃ surface crystallization. In contrast,DOPC monolayer was the inhibitor of the surface crystallization of NH₄NO₃.