Effect of confinement on the fluid properties of ammonia in mesopores of MCM-41 and SBA-15.

The effect of pore size on capillary condensation and solid-liquid phase changes of ammonia in MCM-41 and SBA-15 was studied by adsorption and FTIR measurements of condensed phases at low temperatures. Adsorption isotherms are all typical type IV on the fully hydroxylated surfaces, without hysteresis loops in the smaller pores (d < 2.4 nm).