Topographical properties of polymer films deposited in capillaries for electrophoretic separations of large organic molecules.
Topography and thickness of hydrophilic polymer coatings of fused-silica capillaries for capillary electrophoresis (CE) were investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and profilometry. Three hydrogels, poly(2-hydroxyethyl methacrylate) [poly(HEMA)], poly(diethylene glycol monomethacrylate) [poly(DEGMA)], and poly(triethylene glycol monomethacrylate) [poly(TEGMA)], were deposited using two procedures, either by simple physical sorption of the polymers, or by derivatization of the capillary wall surface with glycidyl methacrylate (EPMA) followed by polymerization of the appropriate monomers. The performance of the modified capillaries was tested under CE conditions (decrease in the electroosmotic flow, EOF dependence on pH, separation of milk and standard proteins). It has been found that the most important property of the polymer coating is its thickness, whereas its topography and the degree of its hydrophobicity are less significant. Film deposition by physical adsorption is preferable to polymerization on the derivatized surface.
Guryca
Vilém
V
Department of Analytical Chemistry, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic. guryca@imc.cas.cz
Pacáková
Vera
V
Tlust'áková
Marie
M
Stulík
Karel
K
Michálek
Jirí
J
D000327:Adsorption; D000818:Animals; D007611:Aprotinin / Q000737:chemistry*; D002256:Carbonic Anhydrases / Q000737:chemistry*; D002417:Cattle; D045304:Cytochromes c / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods; D004852:Epoxy Compounds / Q000737:chemistry; D021621:Imaging, Three-Dimensional / Q000379:methods; D008567:Membranes, Artificial; D008689:Methacrylates / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry*; D011102:Polyhydroxyethyl Methacrylate / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
D004852:Epoxy Compounds; D008567:Membranes, Artificial; D008689:Methacrylates; D011109:Polymethacrylic Acids; C510557:poly(diethylene glycol monomethacrylate); C466018:poly(triethylene glycol monomethacrylate); D011102:Polyhydroxyethyl Methacrylate; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D012822:Silicon Dioxide; D045304:Cytochromes c; D007611:Aprotinin; D002256:Carbonic Anhydrases; C007870:glycidyl methacrylate