Silica-supported comb-shaped polymer (Sil-ODA18) provided a specific selectivity towards aromatic and non-aromatic solutes. Selectivity of Sil-ODA18 and ODS (polymeric and monomeric) columns towards polycyclic aromatic hydrocarbons and geometric isomers have been discussed in respect of molecular shapes and sizes. The retention versatility of this phase arises from the orientation change on transition from the ordered crystalline to the less ordered non-crystalline state. Selectivity in the crystalline and non-crystalline regions of Sil-ODA18 is similar to that of polymeric and monomeric ODS phases, respectively. Sil-ODA18 column also exhibited the characteristic temperature dependency of liquid-crystalline phases, i.e., an increase in retention with increasing temperature on transition from crystalline to isotropic state.