Polypropylene hollow fibers modified with PMMA for capillary electrophoresis

Abstract

A method for modification of polypropylene hollow fibers using graft copolymerization of polymethylmethacrylate (PMMA) was developed. The unsaturated residues in polypropylene were reacted with borane‐dimethylsulfide, and PMMA was graft polymerized on the surface to form a stable coating which reduced the electroosmotic flow and the adsorption of biomolecules. The PMMA modified polypropylene exhibited a lower EOF than fused silica and polypropylene, close to that of bulk PMMA. Samples of nucleotides and pyridines were used to demonstrate the performance of the modified columns. Approximately 100,000 theoretical plates were obtained for lysozyme variants. © 1998 John Wiley & Sons, Inc. J Micro Sep 10: 605–609, 1998

Biochemical analysis with microfluidic systems

“…(1). In agreement with experience from capillary electrophoresis [48] the EOF is lower in most polymeric capillaries, because of the reduced surface charge density on polymeric surfaces. This is proven by investigation of the EOF in capillaries modified by chemical surface treatment or adsorption of polymers or detergents.…”

“…Silanol groups on the surfaces of fused silica capillaries are minimally ionized at pH 3, resulting in a low EOF; increasing the pH increases the density of negative charge on the capillary surface, and thus the EOF, with a sharp increase from pH 4 to pH 6 and minor increases at higher pH [24,49]. Depending on the pK a of other functional groups present on the capillary surface as consequence of the capillary material or surface treatment, the pH dependence is more or less pronounced in the pH range investigated and more or less shifted compared with silica capillaries [37,40,41,48,49].…”

Titanium dioxide coated surfaces for capillary electrophoresis and capillary electrochromatography

“…Attention has been denoted to the utilization of plastic hollow fibers in capillary zone electrophoresis, including polypropylene [20][21][22], poly(tetrafluoroethylene) [23,24], fluorinated poly(ethylene propylene) [25][26][27], polyethylene [28,29], poly(vinyl chloride) [28,30], poly(methylmethacrylate) [31,32], and poly(ether ether ketone) (PEEK) [32]. Micellar electrokinetic chromatography separations were carried out in polypropylene capillaries [33].…”

Charged porous membrane structures for separation of biomolecules

“…Various polymeric capillaries were investigated in the CE mode for separation of both biomolecules and inorganic analytes: ethylene/vinylacetate (EVA) [50], nylon [50], poly(methyl methacrylate) (PMMA) [47,50], poly(butylene terephthalate) (PBTP) [48,50], poly(ether ether ketone) [46]. The biggest interest was, however, in polypropylene, used in both the untreated hydrophobic form [48,51], as well as hydrophilized by modification with cellulose [52], sulphonic acid, quaternary amine functionalities [53], dextran [49] or PMMA [54].…”

“…The noisy baseline might be due to the partial washing out of the BSA adsorbed during the previous runs. The following modifications of the hydrophobic PP surface either by dynamic coating or with chemically bonded layers in order to hydrophilize the PP for the separation of peptides and proteins were reported: with acrylamide [48], cellulose [52], sulphonic acid and quaternary amine groups [53], dextran [49], PMMA [47] [54]. This seems to be a good solution when capillary electrophoresis is performed, but in this work, the PP capillary is used only to seal the outer surface of the membrane (the stationary phase) and as a window for UV detection, and there is no large surface area of PP to be in contact with the sample zone.…”