Chromatography Forum

If there is a difference in energy of -H--O< I would expect it to be stronger in water than in a macromolecule as the latter might prevent the preferred linearity of the H bond.
The BET method makes use of the fact that if the pressure is right, nitrogen gas will form a one molecule layer on just about any surface. So why wouldn´t water tend to slightly shift equilibrium toward a polar surface? Also, all or just about all liquids will give laminar flow in the right pipe of all kinds of material.

It's ok. Some will call it 'HILIC', others will call it Normal Phase.
Either description is fine as long as communication is good.

Regarding the original question (HILIC selectivity), I will add my note that selectivity is different between RP and HILIC, but within the HILIC phases, there are also some significant differences.

For example, basic pharmaceuticals are retained on both silica, cyano, and pentafluoropropyl phases, but the retention order follows an RP trend (more carbons means more retention) for cyano and PFP, but NP trend (more carbons means less retention) on silica.