PolyEncap phases are made of silica particles which are encapsulated with an acrylic ester polymer. These polyacrylic esters are covalently bonded to the surface, resulting in a slightly different selectivity compared to conventional alkyl phases. Because of this encapsulation, the phases have a higher stability in basic mobile phases.
| Phase | Modification | Particle size / µm | Pore size / Å |
| PolyEncap C4 | C4 | 3, 5, 7, 10 | 120 |
| PolyEncap C4 | C4 | 3, 5, 7, 10 | 300 |
| PolyEncap C18 | C18 | 3, 5, 7, 10 | 120 |
| PolyEncap C18 | C18 | 3, 5, 7, 10 | 300 |
| PolyEncap WCX | WCX | 5 | 120 |