Porous polymer monoliths (PPMs) for capillary electrochromatography are an attractive alternative to coated silica beads. The channels are filled with a solution of monomer using hydrostatic pressure and capillary action, so no pressure attachments are necessary.

The PPM forms during the polymerization/phase-separation process to create a continuous monolithic material. The UM-initiated porous polymer monolith is formed in situ on the chip in minutes. Once polymerized, no frits are required.

Electrokinetically Generated Solvent Gradients in Chips Filled With a
UV-Initiated Porous Monolith for Reversed - Phase CEC

References:

Ngola et al.,
Porous Polymer Monoliths as Separation Media for CEC Analytical Chemistry; 2001; 73(5); 849-856., Y. Fintschenko, W.-Y. Choi, S. M. Ngola, T. J. Shepodd,
Fresenius Journal 371 (2001) 174 .