Separation system, components of a separation system and methods of making and using them
Permeable polymeric monolithic materials are prepared in a column casing. In one embodiment, the permeable polymeric monolithic materials are polymerized while pressure is applied through a piston having a smooth piston head in contact with the polymerization mixture. The pressure eliminates wall effect and changes the structure in the column. Similarly, some columns that have a tendency to swell in the presence of aqueous solutions and pressurized while the solution is applied to prevent swelling and wall effect. This procedure also changes the structure in the column. The size of the separation effective openings can be controlled by the amount of the pressure and pores eliminated. Uniformity in the direction flow is improved by controlling polymerization with radiation rather than with conducted heat.
1. A method of making a monolithic chromatography column, said method comprising the steps of
(a) adding a polymerization mixture containing a porogen to a chamber,
(b) polymerizing the mixture in the chamber under a pressure of at least 80 psi during at least part of said polymerization to form a monolithic polymer plug in the shape of a chromatography column, at least part of said polymerizing being performed by applying sufficient pressure to the polymerization mixture to prevent wall channeling openings in said monolithic polymer plug and during heating of the polymerization mixture to a controlled elevated temperature, and
(c) washing the polymer plug to remove the porogen.
2. The method of claim 1 in which said polymerization is performed under temperature-time moderating conditions, whereby temperature gradients arc controlled to prevent substantial cross sectional variations in the monolithic chromatographic column.
3. The method of claim 1 in which the monolithic polymer plug is formed in a capillary tube chamber.
4. The method of claim 1 in which polymerizing is performed under a pressure of at least 150 psi during at least part of said polymerizing.
5. The method of claim 1 in which polymerizing is performed under a pressure of at least 180 psi during at least part of said polymerizing.
6. The method of claim 1 in which the pressure is applied in intervals of increasing pressures.