Disposable monolithic column
Permeable polymeric monolithic materials are prepared in a plastic column casing. In one embodiment, the permeable polymeric monolithic materials are polymerized by the application of heat from an external source starting at a low temperature such as 40 degrees centigrade, depending on the mixture and size of the column, and continuing at a higher temperature, such as 60 degrees centigrade. The temperature at the start of the polymerization is low enough so as not to cause exothermal run-away conditions and to avoid high heat of reaction that would prevent a substantially constant temperature across the cross-section of the column. The higher temperature is used after sufficient monomer depletion has occurred and steric interference has increased so the polymerization reaction is sufficiently slow to avoid heat of reaction generation high enough to cause significant reduction in the homogeneousness of the pore sizes.
1. A method of controlling polymerization of a monolithic polymer plug suitable for use in a separating device comprising the steps of:
(a) establishing a polymerization mixture including a monomer and a porogen;
(b) applying ultraviolet or visible light radiation to the polymerization mixture to input energy through the mixture while applying a pressure of at least 80 psi to the polymerization mixture and heating it at a controlled temperature of at least 40° C. to polymerize the polymerization mixture to form a monolithic polymer plug; and
(c) washing out the porogen.
2. A method in accordance with claim 1 in which the step of establishing a polymerization mixture includes the step of establishing a polymerization mixture that includes divinylbenzene.
3. A method in accordance with claim 1 in which the step of establishing a polymerization mixture includes the step of establishing a polymerization mixture that includes glycidyl methacrylate with hydrophobic surface groups.
4. A method in accordance with claim 1 in which the step of establishing a polymerization mixture includes the step of establishing a polymerization mixture that includes urea formaldehyde.
5. A method in accordance with claim 1 in which the step of establishing a polymerization mixture includes the step of establishing a polymerization mixture that includes silica.
6. A method in accordance with claim 1 in which the step of applying pressure is performed by a movable member.
7. A method in accordance with claim 6 in which the step of applying pressure with a movable member is performed by positioning said member to contact said polymerization mixture as pressure is applied during polymerization.
8. A method in accordance with claim 1 wherein the step of establishing a polymerization mixture includes the step of establishing a polymerization mixture comprising a initiator that is activated by light and a photoinitiator.