Phase pure Ca2AlNO3-LDH nanoplatelets have been successfully synthesised by rapid mixing and precipitation from water in air using a colloidal mill. The as prepared nanoplatelets have an average particle size of 250 nm (by TEM) compared to 2.4 mm via conventional coprecipitation. The Ca2AlNO3-LDH nanoplatelet suspensions are not stable, and age post synthesis. TEM data showed that the particles increase in size from 250 to 705 nm after 4 weeks at 8 degrees C. TEM data also revealed that storage at lower temperatures (-20 degrees C) significantly slows platelet growth. Aqueous suspensions of Ca2AlNO3-LDH nanoplates slowly decompose at room temperature.