Newly designed gels for electrophoresis protein separation were synthesized from acrylamide, N,N -methylenebis (acrylamide) and dextran mixtures. Radical polymerization was initiated by ammonium persulfate and N,N,N ,Ntetramethylethylenediamine. The time dependence of absorbance during polymerization was monitored using UV-visible spectroscopy. The exothermic polymerization process exhibited a sharp rise of temperature reminiscent of the Trommsdorff effect. The swelling kinetics of the synthesized gels was examined in deionized water and buffer solutions. One of the challenges was to find an alternative to commercial products, sold as mixtures with no detailed chemical contents, commonly used in sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) for protein separation. For this reason, a systematic comparison was made of the properties of one of the most commonly used commercial gels, Duracryl  from Genomics Solution Inc., and those of the synthesized polyacrylamide/dextran gels.

Monolithic materials prepared from a mixture of n-lauryl methacrylate (LMA) and ethylene glycol dimethacrylate (EGDMA) dedicated to nano-liquid chromatography separation were synthesized using in situ UV polymerization in 75 m inner diameter capillary tubing. A mixture of cyclohexanol and ethylene glycol was used as a porogen to control porosity. While the preparation conditions yielded satisfactory analytical results, values of pertinent parameters turned out to be critical for obtaining columns with efficient separation. In particular, the impact of two key parameters was studied here in an attempt to identify optimal preparation conditions: (a) different concentrations of the crosslinker EGDMA and (b) different porogen compositions while the monomer to porogen ratio was kept constant. Resulting monolithic phases were characterized in terms of permeability, mean pore diameter and swelling using three different eluents (water, acetonitrile and a mixture at maximum viscosity). First, the LMA/EGDMA monolithic phases present peculiar morphology and hydrodynamic properties for 37% by weight of EGDMA, as reflected by the peak observed for their permeability and mean pore diameter. Swelling experiments revealed the coexistence of two phases in the monolithic structure: a highly crosslinked rigid phase which was insensitive to swelling in the presence of solvent and a weakly crosslinked flexible phase exhibiting significant swelling, with a transition to such a biphasic behavior taking place at 37% by weight of EGDMA. The effects of porogen composition and network swelling properties are presented based on a combination of the Flory − Huggins theory of isotropic mixing in polymer solutions and the Flory − Rehner theory of rubber elasticity in the affine network approximation.