What is the difference between Sphereclone ODS1 and ODS2?

Both materials are based on the same silica (porosity, surface area), ODS1 is a low carbon coverage partially endcapped C18, whilst ODS2 has a higher carbon load and is fully endcapped. Due to the nature of the silica (type A, acidic silica) the ODS1 has a selectivity different to many other C18 phases due to the availability of highly acidic silanol groups for strong secondary interactions.